Is Magnesium Stearate Harmful or Harmless: 6 Supposed Dangers
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Magnesium Stearate: 6 Supposed Dangers That Need Attention to Determine if It Is Harmful or Harmless


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Reviewed by Laura Beth Schoenfeld, RD, MPH

One of the benefits of ancestral eating is that you avoid potentially harmful food additives like artificial colors, monosodium glutamate (MSG), and artificial sweeteners.

magnesium stearate
Magnesium stearate is commonly used in supplement manufacturing. iStock/PeopleImages

However, even on a Paleo diet, it can be hard to avoid some fillers, thickeners, and additives. In fact, many common Paleo foods contain more additives than their Neolithic counterparts. For instance, commercial nut milks and coconut milk often contain thickeners like gums or carrageenan, while your run-of-the-mill grocery store whole cow’s milk is additive-free.

In this series, I’ll review the science on some of the most common additives, and let you know whether you should be concerned about consuming them. First up—magnesium stearate.

Is magnesium stearate a harmless additive or a dangerous chemical? Check out this article to find out. #healthylifestyle #chriskresser

What Is Magnesium Stearate?

Magnesium stearate is a salt that is produced when a magnesium ion bonds with two stearate molecules. Stearate is just the anion form of stearic acid. Stearic acid is a long-chain saturated fat that is abundant in beef, cocoa butter, coconut oil, and other natural foods. As I mentioned in my red meat article, it’s also the only long-chain saturated fat that scientists and medical practitioners agree doesn’t raise cholesterol levels, and doesn’t increase the risk of heart disease.

Uses and Function

Magnesium stearate is most commonly used in supplement manufacturing as a “flow agent,” which helps ensure that the equipment runs smoothly and the ingredients stay blended together in the correct proportions. It can also be found in some cosmetics.

Given the seemingly benign components of this additive, it’s a little surprising how controversial it is. There are a lot of misconceptions and inaccurate statements about it floating around the internet, and while I wouldn’t recommend consuming vats of the stuff (not that you’d want to), I think the concern over magnesium stearate is largely overblown.

What Are the Supposed Side Effects and Dangers, and Are They a Cause for Concern?

1. Effect on Immune Cells

One study that many people have used as evidence against magnesium stearate is a 1990 experiment entitled “Molecular basis for the immunosuppressive action of stearic acid on T cells.” This baffles me, and I suspect that anyone using this study to indict magnesium stearate hasn’t actually read it.

In the experiment, scientists isolated T cells and B cells from mice, put them in a Petri dish, and bathed them in a solution containing stearic acid (along with some other components). They observed that the T cells incorporated the stearic acid into their cell membrane, eventually destabilizing the membrane enough that the cell died.

First of all, this study has nothing to do with magnesium stearate. They just used the plain old stearic acid that you’d find in your beef, chocolate, or coconut oil, so this study could just as easily be used against those foods. If you’re going to be concerned about this study (which you shouldn’t be), you’d have much bigger sources of stearic acid to worry about than the magnesium stearate in your supplements.

Second, the study has nothing to do with stearic acid consumed in the diet. Under normal conditions, your T cells are not bathed in stearic acid, even if you consume superhuman amounts of coconut oil, tallow, and cocoa butter.

Finally, the researchers used T cells from mice, and in this case, the results cannot be applied to humans. The mouse cells incorporated stearic acid into their membranes because they lacked the ability to desaturate fatty acids. However, human T cells do have the ability to desaturate fatty acids, so even if you did bathe your T cells in stearic acid, they would be able to maintain their membrane function. (1)

In case you got lost, here’s a summary: this study has no relevance whatsoever to human consumption of magnesium stearate, I have no idea why the study is being referenced in this manner, and you shouldn’t be concerned about it.

2. Concerns about Pesticides and Genetically Modified Organisms (GMOs)

Another criticism is that because stearate is often derived from cottonseed oil, it can be contaminated with pesticides. Keep in mind that magnesium stearate is a highly purified substance, and goes through an intensive refining process before appearing in your supplements. So far, I haven’t come across any reports indicating that magnesium stearate retains substantial amounts of pesticide residue.

As for the concern that cottonseed oil is often genetically modified, the source of crude fat shouldn’t make a difference in the final form of the stearate. Stearic acid is an 18-carbon molecule with a specific chemical structure that will be the same whether the stearic acid is from a genetically modified cotton plant, a bar of Hershey’s chocolate, or a grass-fed rib eye steak.

3. Effect on Nutrient and Drug Absorption

Another criticism is that magnesium stearate might inhibit nutrient absorption. One in vitro study conducted in 2007 found that tablets containing magnesium stearate dissolved more slowly than tablets without magnesium stearate when placed in artificial gastric juice. (2) The study authors concluded that in vivo studies are needed to determine whether this finding has any practical significance. However, an earlier study found that although magnesium stearate increased the time it took for a drug to dissolve, it had no effect on overall bioavailability, as evidenced by blood levels of the drug in test subjects. (3) Further, another study found that levels of magnesium stearate didn’t affect tablet dissolution at all. (4)

All of this information indicates that although magnesium stearate might affect the rate of tablet dissolution in some circumstances, it doesn’t affect the overall bioavailability of the drug or supplement.

4. Biofilms

I’ve seen this claim pop up in a few places around the internet, so I’ll address it briefly. Some critics of magnesium stearate claim that it can induce formation of harmful biofilms in the intestine. (Biofilms are immobile communities of bacteria that form when bacteria adhere to a surface and generate a polysaccharide matrix.) This assertion appears to be based on the fact that soap scum contains magnesium and calcium stearate, so they insist that just as soap scum creates film on your sink or shower, magnesium stearate creates film on your intestines.

It should be pretty obvious that the intestinal lumen is a vastly different environment from a shower door, but some people still seem to be concerned. Rest assured, there is no conceivable reason why this would take place, and I haven’t seen a single scientific article that even hints at this possibility.

5. Magnesium Stearate Allergy

A 2012 study entitled “Magnesium stearate: an underestimated allergen” reported on a 28-year-old woman who had an allergic reaction to magnesium stearate, resulting in hives. I’m very curious about this result, because an allergy to either magnesium or stearate seems highly unlikely, but unfortunately, I don’t have full-text access to that study. But, needless to say, if you develop hives (or another allergic response) after consuming magnesium stearate, you should probably avoid it in the future.

6. Magnesium Stearate in Cosmetics

Magnesium stearate has several uses in the cosmetics industry: it’s an anti-caking agent, a bulking agent, a colorant, and more. In the Environmental Working Group’s Skin Deep Cosmetics Database, magnesium stearate is marked as “low hazard,” although it’s noted that limited data are available on this ingredient.

So, Is Magnesium Stearate Safe or Bad for You?

As a final note, a rat study determined that you’d have to take 2,500 mg of magnesium stearate per kilogram of body weight per day to start seeing toxic effects. (5) That means a 150-pound person would have to consume 170,000 mg per day, which is so far beyond any amount you would encounter in supplements that it’s a non-issue.

Overall, I haven’t found scientific evidence to substantiate the claims against magnesium stearate, and the small amounts found in supplements shouldn’t be a problem for the majority of the population.


Join the conversation

  1. Thank you so much for writing up this article alaying the alarm I just had reading Mercola’s opinion on the subject and finding 85 percent of my affordable supplements have it in them. You present a reasonable arguement that supports what my intuition hinted at!

  2. I’ve been reading a lot about excipients and I’ve determined to remove as many of them from my diet/supplements as possible. While the jury is out on Magnesium stearate I am scanning labels on the many supplements I take, just like I scan labels on packaged foods. Although I’m not discarding supplements that I have already purchased, I am upgrading them as I run out of old and buy new. I will only buy ones that do not contain Magnesium stearate and other excipients. For me there is peace of mind in buying pure powder supplements and putting them in capsules myself. I look forward to the day I can stop taking supplements. When my gut is healed I believe my diet will provide most if not all the nutrients I need.

  3. The stress that some of you are working yourselves up with will cause more damage to your body then the trace amounts of Magnesium Stearate that you consume.

  4. To further prove my point, HCL (hydrocholoric acid) does not have the properties of either of its components hydrogen and chlorine both of which are gases. This is very basic science/chemistry. It scares me to think that most people on here, including the author believe that magnesium stearate should be harmless because hey, magnesium is a necessary nutrient and stearic acid sure enough is a part of beef fat! Stearic acid is also an ingredient in soap but that doesn’t make soap harmless if ingested, does it?

    • Can you tell us any more about Mag Stearate? Or give us any links to understand it further. It’s in quite a lot of supplements that my family is taking. Kind of hard to avoid.

        • I take the info on Wikipedia with a grain of salt. I was interested in her perspective. Thanks though.

          • One ought to take ALL information that someone tells one or writes for one with the proverbial grain of salt. Due diligence is always required. Compare one source with another.

            To be sure about anything you need to confirm it yourself. However, most of us don’t have the time, hence we rely upon culture and the preserved records of others’ work.

            As a science-educated individual I would express the opinion that at least as far as science goes on Wikipedia it is nearly always accurate and consistent with current scientific understanding.

            That’s because of it’s editorial policy and because the vast number of well-educated editors who constantly check the writings of others. The policy is that everything written must be not simply the opinion of the writer but must be sourced and referenced from some other attested published material. Of course, this does not always happen – some people write just anything – but you can always check the references to confirm or otherwise what is written. (If there are no reference to support as statement, treat it like that – an unsupported statement.)

            When it comes to something that is contentious or in dispute – such as the current debate about harmful health effects of Mg Stearate – you can expect Wikipedia to be conservative and in line with general scientific opinion and it probably won’t contain any contentious statements such as the current assertions of negative health effects, precisely because these have not yet had any amount of scientific research applied to them and therefore there is no such published scientific literature to reference.

            Thus Wikipedia (as any encyclopaedia) will always be behind the cutting edge. But as far as the basic science of Magnesium Stearate is concerned, it is very likely to contain exactly that (and not much else). But check against any other material you can find.

      • Check out Paradise Herbs website. I’m not hyping the company, but their stance on Mag Stearate is revealed in an article about it. Good info about it, better than here.

    • Sophie, So agree. What is Science??? It is some person PICKING/CHOOSING variables to work with. Quite subjective if one really, really looks at this with a true open-minded mind, a mind that can see beyond the chains of those CHOSEN variables. (in fact, the big criticism with science is that a so called scientist can handpick variables to result in his/her particular DESIRED outcome. Just look at all the so called scientifically produced products that result in injury and lawsuits. For example, it is ironic that when a drug is ‘studied’, participants must be a selected group of people. That would leave out those with allergies to peanuts, dyes and such who may react terribly to the product. At any rate, if SOME people react to mag stearate, it is not an OK ingredient for ALL people, yet it is on the books as being nonreactive or inert or harmless. To the people who say it should be science over empirical, in plain words, reality instead of hand-picked variables, I don’t even respond back to them. I have a right to say that our very negative empirical evidence should be evidence that mag stearate is not an inert ingredient. The number of responses to this article alone that indicate bad reactions to mag stearate indicate a problem with mag stearate so it just should not be some ubiquitous ingredient in foods/supplements/drugs ESPECIALLY since it has NO nutrient value at all. It’s just used for the machines to be oiled so they don’t wear out processing the stuff.

    • Sophie:

      There are thousands and thousands of examples of harmless man made chemicals. I will grant that there are good examples of where the combinations did not work out so well, but you cannot condemn the entire practice because of a small percentage of failures. BTW, HCL is a necessary chemical combination used by our own bodies. It is not a great example as CL gas is extremely dangerous on it’s own. H2O is just as good an example of gases that form something else… only the most important substance on our planet.

      Magnesium Stearate has been used in medicines, foods, and cosmetics for decades. It is used in over 2,500 medications and is by far the most common excipient found in the top 200 medications used today. Just because a few whiners have made an anecdotal link to it as a problem for them is not enough to write it off as a safe compound. I am amazed at the irrational lengths some of you will jump to in your attempts to demonize this longtime safe compound.

      No Alice, you have anecdotal evidence that proves nothing. The only empirical evidence available on Magnesium Stearate indicates that it is perfectly safe. The hubris you display when you snub your nose at good solid science in favor of your subjective guess that MS is the root of your problems is ludicrous. Even if you were right, it does not make it a problem for billions of others. I would recommend that you avoid it, if you feel you must, and let the rest of the world make their own judgments. Every argument you have thrown at this wall has failed to stick.

      You need to get a hobby… or a life.

  5. If I can recall my basic chemistry lessons from school accurately, magnesium stearate isn’t a water soluble salt. Yes it is derived out of Mg and stearic acid but magnesium stearate itself is a different animal than either of its precursors and it will behave differently than stearic acid which is found in the aforementioned beef, chocolate and coconut oil. Mg stearate does not readily break down into Mg and stearic acid as soon as it is ingested simply because it is not soluble in water. So please people, A+B = C and C is neither A nor B!

  6. Wow thanks so much to the guy who blogged this! I recently saw enough of these alarmist claims about the supposed dangers of magnesium stearate to finally become worried. If I hadn’t finally clicked this page in my search results (it seems to be the only non-alarmist result btw) I’d probably would’ve started obsessing about it! I’m really glad someone has taken the time to get to the real truth of the matter.

  7. You mentioned that a young woman developed hives taking magnesium stearate in her vitamins. I have been itching all over ever since I changed my vitamins to ones containing this product. I have been searching for the cause for a month. Thanks for sharing her story. I plan to discontinue this brand to see if the itching stops

  8. To everyone,

    I have spent a serious amount of time researching this topic, primarily because I want to know… all I find is article after article like this…
    All touting the safety of magnesium stearate, with several exceptions that were not “scientific” studies, but personal commentaries.
    I think that those of you who have had “negative” experiences should get together and start a blog or website, and gather all the personal stories you can, and then present this to the general scientific community, and see if there is interest in actually determining the truth…
    Just my opinion…

    • Hear, hear!!! These folks with all of their “empirical” evidence are convinced they are RIGHT, and will holler to the rooftops until people give in and admit they are RIGHT!!!!

      It would make sense for them to gather on a site of “like-minded” people where they can trumpet their “beliefs” to each other.

      Then, once a large consensus of information has been compiled, hopefully someone in the scientific community can be convinced to perform peer reviewed testing that can help settle the matter once and for all.

      • Shawn, Alice and others are not presenting “empirical” evidence. They are presenting “anecdotal” evidence. Empirical evidence is scientifically-based. Anecdotal evidence is based on personal experience.

        • ROTFLMAO!!!! I let her crap get me so worked up that she managed to confuse me. Naturally I know the difference. I just let her screwy reasoning mess with my thought processes. Hey at least it was good for a laugh, eh?

          • Hey Shawn,

            You were right, though, in what you clearly meant. Anecdotal evidence is nearly always the precursor to the gathering of empirical data by scientifically designed studies.

            Once the empirical data is in, we can dispense with the anecdotal – unless the research fails to account for the anecdotal evidence AND it continues to present, unexplained, in the light of new understanding gained by the empirical studies.

            In this case we simply need more studies to examine other possible causes for the unexplained.

            • Thank you Hedles. I have a ton of stuff going on in real life, so that post was not well thought out. On top of the normal stuff, I went and let the extremely dysfunctional Home Owners Association here make me the President. I hate bickering and whining but as I read my posts here, I have not been very charitable while making my points. In acting that way, I have allowed myself to drop to the very levels I so detest. Fortunately, I now realize I have been letting the stress get to me and can take action to alleviate it.

              Again, thank you for your kind response.


  9. I don’t know about tests or anything on magnesium stearate. However, I cannot take it period. This is curious because I took it all last year after developing A fib and BUT I took Natural Calm for a year or more and all of a sudden one dose gave me hives forever. I was miserable. I told my nutritionist and he gave me some Standard Process mag. Same reaction. SO after stopping all supplements and adding back one at a time, doing mag last, it was absolute confirmation. I have since been using magnesium chloride brine transdermal and it works fine.
    Having a little adrenal problem this past week, my nutritionist gave me some Standard Process Adrenal Complex. I did not look at the ingredients as he and I agreed no mag stearate. After taking 3 pills, the reaction came just like the magnesium. Looked at the ingredients and sure enough mag stearate. It is a puzzle. All I know is, my body is rejecting it big time and I have no idea why.

  10. I’m skeptical of that study on rats. Let’s examine who funded the study. Also, did they use just one form of mag stearate? Can’t it be made up of different things? Instinctively, I would not feel comfortable nor feel it justified to take supplements on a regular basis that were made from cottonseed oil or corn (knowing that the source was probably GMO), no matter what ‘study’ proved it harmless at those amounts.

    • Susan, well said. I think when it is all done and said, the ones here who are making money from the sale of supplements/drugs, they will find the ‘so called’ studies to support the use of what makes them the most money. It is almost funny listening to drug commercials on TV. They show people having the most wonderful time cuz they took a drug WHILE the drug side effects are softly stated in song like voices. MY GOSH, The side effects are always worse than the symptom the drug is supposed to relieve. That’s what it comes down to with additives like mag stearate in supplements and drugs. If some real research was done and the bad side effects were discovered, supplement and drug producers would just get some sing/song language and even make it sound positive like, if you get an erection that lasts for 4 or more hours, go to the ER. (What a backwards way to advertise) If nothing else in that ad convinces the man that this is what he needs, that so called ‘bad side effect’ will get him running to get the drug. Bottom line, I don’t take drugs, stay away from doctors. If one eats right, don’t need them. I also don’t take supplements excepts for a few that I seek out in pure powders. IF one eats right, don’t need them. Side effects from additives in supplements will continue to be denied by the makers of them cuz money talks.

      • Aha Alice! Gotcha!!!

        You state:

        “Bottom line, I don’t take drugs, stay away from doctors. If one eats right, don’t need them. I also don’t take supplements excepts for a few that I seek out in pure powders.”

        You are here telling everyone else how to live their lives when you state that it minimally affects yours. You claim to be disease free and that we could all be disease free if we “eat right.” That my dear is the ultimate in hubris and hypocrisy. Of course, given your posts here, I should not be surprised.

        Chris Kessler wrote a well reasoned article, which Mr. Paleo, Hedles, and others like myself, defended in the face of specious empirical evidence and total falsehoods.

        Your best course of action is the advice found under this heading:

        MR PALEO
        FEBRUARY 4, 2014 AT 11:56 AM

    • Lora,

      As I have stated previously, Chris may (or may not) be omniscient, but, in my opinion, he does know his biochemistry, and practices due diligence when analyzing and reviewing a given subject. Just because one does not understand something does not mean it is necessarily appropriate to criticize the messenger… but it is your choice…

      • Did you open the website??? WOW, THERE this is said:

        “Magnesium stearate affects the respiratory system as well. When someone inhales the powder or fumes of magnesium stearate side effect, he may get some of the structures of the respiratory system inflamed. He is most likely to develop asphyxia, which is physiological condition wherein there is either no or insufficient oxygen and carbon dioxide available to the body. It may result in unconsciousness or even death. It may trigger allergic reaction in people. Such people mostly include those who are sensitive to food additives.”

        Now that is exactly the reaction I get, not when I inhale it of course, but when I ingest it. While I Love Chris, my EXPERIENCE says he, as a messenger, didn’t realize the ill health effects including possible dangerous reactions to the heart and air pathways of our body. The fact that mag stearate is added solely for the machines, just CHUCK IT. I believe IF the research was done, mag stearate would be found to affect many people.

        • Alice,

          Yes, I reviewed what was presented, however, there were several misleading statements which, for me, cause concern about the accuracy of the material presented.
          Let’s just take the one you emphasized, ok ?
          Just about ANY “powdered” material can cause the symptoms described if inhaled, this is not necessarily due to the chemical nature of the material, but rather the lungs reaction to an irritant… many persons who are “sensitive” to inhaled irritants, such as asthmatics, would react this way. All I am saying is that Chris is not perfect, you are not perfect, I am not perfect, no “one” is perfect, none of us “know it all”. So one must pick and choose their sources based on a certain level of proficiency… and for me, Chris meets that required minimum. Now, as an addendum, BECAUSE of what has transpired on this particular blog, I now make it a point to recommend supplements which DO NOT contain Mag stearate, just to be on the “safe” side…

          • Mr Paleo, Your statement:

            “Just because one does not understand something does not mean it is necessarily appropriate to criticize the messenger… but it is your choice…”

            THAT statement made by you shows inability to discuss. If an opinion does not fit with you, then it is me or us that do not understand. Those of US who have had horrible lung reactions NOT FROM INHALING but from INGESTING mag stearate, we have EMPIRICAL evidence so we DO FULLY understand. IT is people/doctors like you who are CLOSE minded and think they found the ONE RIGHT answer that can make life miserable and even deadly for some people. Just look at the statistics of how many people die from dyes in contrast exams. Yet the medical system continues to use them. Attitudes that say just because some SO called experts say it is OK cause this end result. Same goes for mag stearate, a group of people (probably much larger than imagined) DO react very negatively with digestive issues and lung issues and fast pulse/heart palpitations. Just cuz you don’t react negatively to mag stearate does not mean you found the ONE right answer or the ONE right person that shows mag stearate is safe. BOTTOM LINE, a USELESS MAN-MADE QUESTIONABLE ingredient should not be a ubiquitous ingredient in supplements and drugs. To say it appears naturally in foods is as crazy as saying that processed junk food is as good as the apple. Something chemically processed is not the same as the apple. Ingredients that are chemically processed to BECOME an ingredient found naturally in a food are not the same as eating the apple with that ingredient in its natural form in context with whole apple. Chemically made stuff is not the same as the natural food. As Nurse said
            January 24, 2014 at 9:23 pm,
            “WHEN IN DOUBT, DON’T.” There is NO room in a discussion like this to tell us we just do not understand cuz our opinion/EXPERIENCE differs from yours. I perceive you as the one who does not understand this one. While I do appreciate all that you do understand in your position, this one I feel you missed the boat. AND let me also reiterate, I admire Chris and believe in his work and FULLY appreciate his knowledge but we are ALL continually learning and by coming to a conclusion along my path that differs from a conclusion he made along his path in not way degrades Chris in my eyes. It is only when one is so close-minded that they have to be right just because their evidence worked for their experience that I loose faith in them. That IS NOT Chris for sure. I follow him because he is so open-minded and presents cutting edge knowledge.

            • I have spent hours researching this subject, and discussing it on various forums. The simple fact is that every single objective breakdown of the “controversy” surrounding magnesium stearate concludes that there is absolutely no reason to believe that it presents any danger. I brought up some of the studies I found, and was pointed to many reasonable arguments why the studies were not relevant to this discussion. I am sorry for those few people on this forum who feel they suffer one malady or another that they blame on magnesium stearate. It is important to note that even if they could be sure, it doesn’t mean the other 99.9% of the population needs to get worked up over their issues. The protestations a few of you are “loudly” adding to this discussion are not made valid just because their .1% of the population claims “empirical” evidence.
              Note: definition of empirical? “relying on experience or observation alone often without due regard for system and theory.” Your choice of words, not mine. That leads back to the point by the more reasoned responses that are informing the public that ignorance of the facts does not strengthen your argument. Instead it demonstrates that you refuse to face up to the FACTS we have available to us and prefer to judge using conjecture instead.

            • Another important point. The stearate molecule is the same regardless of it’s origin. You can call it crazy all you want, but it is an immutable fact. When the facts don’t square with your hysterics you tend to fall back on unsupportable arguments like this one.

              • YES Shawn, You don’t have true empirical experience, you just have some SO CALLED BOOK evidence, which is someone deducting something about how a particular thing is OK. No true study has been done, just deductions of how mag stearate is OK cuz it is natural in veggie/fruits. You can ingest it, I never said you could not have it. LAP it up but don’t sit on your high horse and say it is OK cuz it works for you. MAYBE it does not work for you and you just don’t realize it. Anyway, I don’t care who ingests it, I will continue to say that some ingredient that is chemically processed and used only for a MACHINE should not be in everything. Empirical experience is real, your way of someone just making deductions without any study is not real. You can research yourself stupid (that is what really must have happened) by reading deductions made by various authors. Now you are a slave to those authors who seem to have said what you want to hear. NO where is there an actual double blind type study on mag stearage, just deductions. It is people like you who statistic around with 1 Percent and such do react that makes our products full of junk and with risk. Are you not able to think of things like WHY has asthma suddenly jumped up to epidemic rates. For all you know, everyone of these asthma patients may react to mag stearate but so what according to you. Since it does not bother you, just let them ALL suffer. I am not going to say more here as money is at the heart of this issue. MOney matters and not how many people could be hurt, just sell those supplements How many times have things come around to be changed cuz some study brought to light how a particular thing really is very harmful after all. Well, along with “oleo” and all the rest, mag stearate could join those ranks as really open-minded intelligent people do real studies instead of so called research of opinions.

                • Alice:

                  So, simply insulting me and dismissing all of the logical data on the safety of magnesium stearate is now going to be your approach. You are operating on multiple fallacies, and believe that a few people who think magnesium stearate may be causing them problems (none of you can actually prove it). You slam, so called deductions made on logic, but consider “empirical” evidence to be the end all on the subject. Your narrow-minded way of deciding your course of action on this subject may work in your mind, but anyone using logic would give it the attention it deserves… very little. At no time in the discussion have you presented a single bit of creditable evidence that magnesium stearate is anything but harmless. You have attempted, and failed to tie it to other supposed health scares, but they are not relevant. The only way that money matters in this discussion is that the few people who claim magnesium stearate is harmful are doing so to sell their overpriced, and sometimes inferior products. You present “empirical” evidence, which by it’s very nature is biased, as being superior to actually researching the facts regarding this subject. I’m sorry, but that makes me much more open-minded than you. Get over it. Logic trumps your biased opinion every time
                  You have the ability to choose the products that do not include magnesium stearate and the rest of the world can safely choose from the thousands of products containing magnesium stearate if they so desire. Just let it go at that. You are beating the proverbial dead horse here.
                  P.S. Calling me stupid does not make you any smarter. I am quite confident in my intelligence.

                • Alice, it’s not true that magnesium stearate is “only for the machines”. It is used to make ingredients flow, because sometimes they stick and clump together. If they clump together, you won’t get accurate dosing in your supplement. This is not a cost-saving measure for a manufacturer, it’s a quality control measure. Your claim that it’s all about money is way off the mark.

  11. WHEN IN DOUBT, DON’T. For many years, most of the supplements I purchased have contained stearic acid and/or magnesium stearate. Having done my own research on these two additives, I will definitely be switching to organic whole food supplements from now on. One report stated that the presence of these particular stearates in a formula reduces the absorption rate of the supplement to only 25% – 30%. No more for me. Yes, it will cost me more initially, but not as much as I have already spent on products that have done me very little good and may have even harmed my system, thanks to these two culprits that I assumed were safe for consumption.

  12. I was told by my holistic doctor that it is converted into a trans fat (hydrogenation process)…and trans fats are bad so I am it trans fat or isn’t it? Thanks!

    • There are statements of “prediction” and “interpretation” (i.e. “mag stearate is good for you/bad for you”). Then there are statements of irrefutable fact, i.e. regarding the chemical structure of a substance. This is an issue of FACT. Simply put, a fatty acid may be a trans-fat; it may be a saturated fat; but it cannot be both. Period.

      Hydrogenation is a process which can turn polyunsaturated fats into both trans-fats and saturated fats. But the same process can have different results.

      And let’s not forget, even if we were talking trans-fats, 2% pill weight of a 500 mg capsule is 10 mg, of which about 70% is stearic acid, or around 7 mg. 1,000 mg in a gram. 28 grams in an ounce…. You do the math! 🙂

  13. I dare say, there is one common denominator that is not being given the attention it so richly deserves, and that CD is GMO’s (genetically modified organisms). If what you are consuming contains ANY ingredients derived from GMO products, then you can expect gastric upset, amongst other repercussions. Cottonseed Oil was originally used as machine oil. I consider myself to be much more than a mere machine. At last finding from those in the agricultural “know”, all cotton grown in the US is GMO. So if what you are eating contains cottonseed oil, you are most likely getting all the wonderful benefits or should I say side effects of eating GMO products, which are too numerous to recount here, but one of which is gastric upset. I do maintain a belief that GERD is caused by ingesting GMO products, due to my own personal experience. Take all GMO products out of your diet, or go 100% Organic, and see how much your own health will improve, first of all your digestion. And yes, if you have been taking antibiotics, replace the beneficial flora in your digestive tract with pre- and pro-biotics, and include digestive enzymes for your stomach. GMO’s were designed to destroy the digestive tract. Destroy the digestive tract, and you destroy the organism. For future reference, check out Super Natural Silver Sol(ution), to use instead of antibiotics. Silver Sol has no known side effects, including argyria, and kills bacteria, viruses, fungus, mold, and pathogens like malaria, which are parasites. Surgeons are spraying it on surgical masks, and finding the solution to be as effective dry as it is when wet, killing pathogens on contact. Silver Sol does NOT promote the growth of candida. I will have to agree with Alice, as I no longer see any benefit to antibiotics as long as I have Silver Sol, which is also available under the Natures Sunshine label. This solution taken via nebulizer, is the best way to get the silver into your system, and as an added bonus, it will clear up respiratory infections. In the gel form, when applied to moles and warts, the skin lesions eventually fall off. These conditions are caused by viruses, and this silver solution kills them most effectively. (A word to the wise, this is not ionic or colloidal silver, and it is produced under a patented process, making it the only one of it’s kind). Awesome! After all, YOU are the only one ultimately responsible for your own health, as you will be the one who will pay the ultimate consequential price if you don’t practice due diligence on your own behalf. Carpe Diem!

    • Well said JR, I was going to make a similar point. The author merely glosses over the GMO aspect and instead was concentrating on the pesticide residue. This stuff is built right into the plant’s genetics itself, and I find this glossing over and nonchalant dismissal of the GMO aspect to be alarming, given what we know about GMO’s from true independent studies.

      • Assuming you accept that the fundamental picture of modern chemistry and atomic physics – for all practical purposes – accurately represents the world we live in (but don’t get me started on philosophy of science!), then whether the raw stearic acid is derived from GM cotton seed or any other source has almost nothing to do with this debate.

        For a short explanation, please see my reply above, beginning, “Linda, you are right that no-one yet knows all the effects that GM …”.

        In short, there is only one form of stearic acid and all molecules of this are identical, no matter where they are sourced from. Only in the unlikely event of some genetic material or other contaminants such as glyphosate making it through the extraction and manufacturing process into the final magnesium stearate product could this have any effect. See my above referenced comment for the reasons why this is very unlikely.

        • Would have to disagree. Some say synthetic vitamins are the same, structurally, as natural vitamins. Even though mainstream science believes this, I do not. Some have argued that all fluoride is the same because it is the fluorine ion that makes it so. I would argue that the toxic waste they dump in our water supply is far different than that occurring naturally. Mainstream science is limited and much of it is used for propagandistic purposes.

        • And there is a big component that your missing. There is a nonphysical component to reality that most people leave out and which is very difficult to prove because we do not have equipment to measure it yet. Example: We all have the same components that make up our DNA, yet some people have extraordinary abilities, while others do not. Wim Hof is able to raise his body core temperature at will. Science cannot explain it, yet there it is. Perhaps it goes beyond what we can perceive physically.

          • We all have the same components that make up our DNA. Sure, why not say it that way? In the same sense, my reply has the same components that make up your reply: letters, punctuation, spaces. Yet they say very different things! This does not mean that the meaning and content of one piece of writing vs. another transcends words and grammar…

            • The point I was trying to make is that there are anomalies that are verifiable that science cannot explain….yet. Just because things “seem” to be that way now “scientifically” doesn’t mean they always will. And mainstream science is limited. We are all made up of the same building blocks…more or less…yet some possess abilities that are far beyond others or “impossible”. Just because things look the same from a mainstream science point of view doesn’t mean they are. I used the example of Wim Hof earlier who can raise his core body temperature even when submerged in near freezing water. Science can’t explain it, yet how much different is his physical, scientific make-up?

          • Rudy,

            I agree with a lot of your ‘sentiment’, but I would express it differently.

            I did issue a warning not to get me started on the philosophy of science, but there is really no other alternative to reasonably address some of the issues you have raised in all your posts to date – not just the one above.

            “Science” means knowledge. What do we actually ‘know’, and what components of ‘science’ are actually knowledge as opposed to opinion, guesswork, theory or (political) propaganda?

            I would argue that the only components of what is commonly understood as ‘science’ that can reasonably be regarded as true knowledge are the data that are the results of scientific observation and measurement and the mathematical relationships between those data.

            Everything else is ‘theory’ or ‘working hypothesis’ or just pure guesswork or wishful thinking or propaganda.

            Every time a scientist draws a conclusion about the nature of physical reality from experimental data, s/he is doing one of three things: either extrapolating (or interpolating) from the actual results to a larger domain than the results can prove, or proposing a picture or an image of reality that we can visualise, or proposing a mathematical model of that picture which can be used to predict the results of further experiment. Normally these three activities follow in approximately that sequence but with a great deal of feedback from later to earlier stages that modifies the earlier output. All three of them can be classified as scientific theory.

            Once a mathematical model has been proposed, it can be tested – first, to see if it is self-consistent, second to see if it correctly predicts the results of previously untried experiments.

            Once it has passed these tests for a reasonable length of time without failure, confidence grows in the model and it can become elevated to the status of an accepted scientific theory.

            In my opinion, a big problem is that once a theory has been accepted for a good length of time, many people, sadly including many scientists, begin to confuse the theory with reality.

            In fact, the theory is only ever a model of reality – one that usually expresses much of the knowledge (experimental data) that we have collected so far.

            So when you say that there are some observations that science cannot explain, I agree with you completely. “Science” is a work in progress and biological science is particularly complex and ‘never-ending’, so perhaps at some point science will catch up with some of these unexplained observations and incorporate them into its model.

            This is precisely why I began my first post with, “assuming you accept that the fundamental picture of modern chemistry and atomic physics … accurately represents the world we live in”.

            That accuracy is a big assumption! But there is very good reason to make it. Much of the scientific model we currently work with has been exhaustively tested over many decades for compliance with reality – not just by direct scientific experimentation, but by engineering applications from the construction of skyscrapers to the manufacture and use of electronic devices – and it is able to correctly predict many experimental results as accurately as we are able to measure them.

            However, none of that means that the model is complete or that there are no future results that will cause us to revise the model. Nor does it mean that there might not be some completely different model that predicts as well as or better than the currently accepted model.

            Even, for example, the atomic model of reality could be challenged. Nobody has ever seen
            an atom with their naked eye, nor heard one, smelt one, felt one or tasted one. We have seen pictures of atoms, generated by scientific instruments. But I could easily create an image of what I imagine an atom looks like and that would not prove that the atom exists. The difference is that these so-called ‘images of atoms’ are generated by an instrument that is supposed to be sensing the atomic structure of some piece of matter. However, the logical flaw is that the instrument is constructed and the image generated based on many layers of theory that assume the existence of the atoms being imaged.

            Nothing in science or logic can prove that atoms must exist. So, logically, it is entirely possible that some day an alternative mathematical model not invoking atoms might be constructed that delivers results as or more accurate and consistent to reality as the atomic model we have today.

            For the time being, however, the atomic model is extremely successful and it is the only model we have that fits so widely into our intuitive understanding of reality.

            – – – – –

            Some synthetic vitamins may have the exact same structure as the naturally occurring, others definitely do not – and any biologist who has knowledge of the subject would agree. What is often different, however, between vitamin supplements and vitamins in their natural context, is precisely that – the chemical context – the soup of other enzymes, proteins and chemicals of all kinds that are part of the natural package.

            Naturally fluoride is not the same as “the toxic waste they dump in our water supply”. There is no question about that. Anybody who says otherwise is suffering from an overdose of propaganda.

            You speak of “a nonphysical component to reality” and then cite as an example “Wim Hof is able to raise his body core temperature at will.”

            To me this does not sound like a nonphysical component to reality. Body temperature, is surely a physically measurable value. If Hof has found a way to control his bodily control system by application of his decision making power, then there is some prospect that scientific observation of his feat might be able to understand the physical processes involved and even eventually be able to teach others to do the same.

            However, I do not dismiss your suggestion that there are nonphysical components of reality. It is certainly possible that there is a spiritual world ‘within’, ‘around’, ‘above’ and ‘beyond’ the physical realm. To me nothing else could explain the existence of the physical universe. Big bang or no big bang, the universe is not a logical necessity.

            However, the difficulty for scientific exploration of such metaphysical reality is that what we cannot observe and measure repeatedly and reproducibly cannot form the basis of scientific data – certainly in the sense of modern science since Galileo. Where the spiritual impinges upon the physical with a measurable physical impact we might begin to investigate, but where there is no such impact science cannot begin.

  14. Thanks for your thoughtful analysis of magnesium stearate. However your article fails to discuss the only issue that really matters when it comes to magnesium stearate — namely, is the magnesium stearate made from hydrogenated oil?

    • manufacturer’s safety data sheet, brilliant Kay to look at this AND it is not good. (skin & liver toxin) Also, Paul, YES, is it a hydrogenated oil? That is what I said a number of times, why would we put a little bit of hydrogenated oil into our body every time we take a capsule for nutrition or supplement. Over the weeks/years, a little ends up as a lot. And for some reason, I get heart/lung reactions from it.
      Why is this not said about it or is it really a hydrogenated oil or what???

      • If the magnesium stearate is made from stearic acid extracted from a vegetable or animal source, then it is NOT hydrogenated.

        Hydrogenation is a process for saturating (or partially saturating) unsaturated fats.

        Stearic acid is a saturated fat. There would be absolutely no point in trying to saturate it, because it is already saturated.

        If you made stearic acid from an unsaturated fat, by hydrogenating it – unlikely because it is readily available direct, it would still result in a saturated fat (stearic acid) and as I wrote in one of my other replies, stearic acid is stearic acid is stearic acid.

        The danger of hydrogenation is not in the word ‘hydrogenation’ or in the fact that certain products have been made by hydrogenation. The danger is in the damaged fats (e.g. trans fats) that can be produced by the process. However, if the product you seek is a (fully) saturated fat such as stearic acid, it matters not a jot whether it was made by hydrogenation or extraction from a ‘natural’ vegetable or animal source or otherwise, because there is no trans or other damaged form of stearic acid. Stearic acid is stearic acid is stearic acid.

        [There is some chance that a small amount of damaged fat that had not been fully saturated could be left in the stearic acid product after hydrogenation then separation, but since it is likely that there will be at least two further extraction/filtration/separation processes following that after hydrogenation, it is very unlikely more than an insignificant amount would contaminate the Mg stearate. Then consider that the amount of Mg stearate actually used in tablets is tiny and all you will get is a very tiny percentage of extremely small.]

        • Thankyou, Hedles! Always a pleasure to have someone address issues of fact…. er — how do I put this? — FACTUALLY! 🙂

  15. I spent a long time writing about my own research and opinion about magnesium stearate and it suddenly disappeared.
    So here’s the short version: Just do an online search for the MSDS (manufacturer’s safety data sheet) and you will see that it is considered a skin and liver toxin.

  16. Thank you, thank you, thank you for being a voice of sanity and intellectual rigor in this wilderness of self-proclaimed “experts” and alarmists and wanna-be natural med celebrities. I read your piece on mag stearate, and I’ve skimmed another few now. There aren’t that many of us out there who are doing what you do. Keep up the good work.

  17. My #1 question is “does Mr. Kresser have an axe to grind regarding magnesium stearate”?

    Additionally, in reading his article, one must be aware of the #1 greatest human frailty, i.e., tending to believe what one wants and needs to believe.


  18. I came to this site because I have two overlapping auto immune diseases both of which cause a lot of pain. I do not take pain medicine on a regular basis but when I do I have noticed that if I take Hydrocodone I get mouth sores and gum boils. This does not happen if I take the same dosage of Oxycodone. I researched the ingredients of both meds, active and inactive, and compared. The only thing I found different is that Magnesium Stearate is used in the Hydrocodone pills and not the Oxycodone. I am wondering if this could be the cause of the mouth sores and gum boils. I have not found anything referencing this side effect.

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