7 Tips for Preventing Colds and Flus | Chris Kresser
Interested in becoming an ADAPT Certified Functional Health Coach? Early Bird Enrollment starts on August 17th Learn More

7 Tips for Preventing (And Shortening) Colds and Flus


Last updated on

Cold and flu season is upon us—but that doesn’t mean you have to suffer. Check out these tips for supercharging your immune system and boosting your resilience.

preventing a cold
Knowing how to prevent a cold or the flu is your best chance for a misery-free season. istock.com/AlexRaths

Conventional wisdom holds that there’s not much you can do to prevent colds and flus—and even less you can do to treat them. Of course you could get a flu shot, but research suggests they aren’t nearly as effective as many believe. OTC remedies like antihistamines, decongestants, and NSAIDs can suppress some of the symptoms associated with colds and flus, but they do nothing to prevent them or shorten their duration. And while antibiotics may be necessary in certain cases (e.g. a cold that progresses to a severe sinus infection, though even this is debatable), they aren’t useful for treating the viral infections that cause colds and flus.

Cold and flu season beating you down? Check out these 7 tips for boosting your immune system.

But here’s the good news: there are, in fact, several steps you can take that will strengthen your immune system and not only decrease the chances that you’ll get sick in the first place, but help to reduce the intensity and shorten the duration of any cold or flu you do get. Instead of just suppressing symptoms, these tips will actually improve the function of your immune system as well as attack the viruses themselves.

#1: Load up on Immune-Boosting Nutrients

There are several micronutrients that are essential for immune health. Many Americans don’t get enough of these nutrients through their diets. But even if you are getting enough, taking additional amounts of them when people around you are sick, or if you’re already sick, can be a big help. These include:

  • Vitamin C. Liposomal forms are best absorbed. I suggest one teaspoon once a day on an empty stomach for prevention, and one teaspoon twice a day for treatment. If you’re using ascorbic acid, take 1,000–4,000 mg/d, up to bowel tolerance.
  • Vitamins A & D. Both of these fat-soluble vitamins are important for immune health, but here’s a little-known fact: research suggests that they are only effective for preventing/reversing colds and flus when taken together. This is why I’m such a proponent of cod liver oil: it contains natural forms of both A & D in a synergistic blend. I recommend Extra Virgin Cod Liver Oil from Rosita as my preferred cod liver oil product. For more information, read this article. You can purchase EVCLO here.
  • Selenium. Selenium helps to balance and regulate the immune system. Most Americans get enough in their diet, but taking a little extra during cold and flu season can help. I suggest 200 mcg/d 3-4 times a week. This is the brand I recommend. Note: I do not recommend long-term, continuous selenium supplementation because it has been associated with increased risk of prostate cancer in men.
  • Iodine. Iodine also plays an important role in immune health, and many Americans don’t get enough of it. Ironically, this is especially true for health-conscious people that have removed iodized salt from their diet. The only significant sources of iodine in the diet are sea vegetables, fish heads, and dairy (especially pasture-raised dairy). If you’re not eating these foods regularly, you may want to supplement with about 1 mg per day of iodine in the form of kelp capsules. Note: some people with autoimmune thyroid disease cannot tolerate iodine even in this relatively low amount, so exercise caution if you have Hashimoto’s or Graves’.
  • Zinc. Zinc is another immune-boosting nutrient that many people don’t get enough of. If you like oysters, they are your best bet for meeting zinc needs through diet. You can also take 30 mg/d of zinc picolinate or zinc gluconate for short periods when you feel you’re fighting something.

#2: Drink Fresh Ginger Tea

Ginger is a potent anti-viral substance that prevents the adhesion of viruses to the upper respiratory mucosa.

If you drink the concoction I recommend below at the first signs of sickness, you can often fight it off successfully. But—and this is a big “but”—you have to drink it at or near the strength I suggest, or it won’t be effective. Some people find this difficult to do, because ginger is so intense, but if you can handle it your immune system will thank you.

Also, while it’s possible to do this without a juicer, it will take a lot longer. You can get pretty good juicers now for less than $100, so if you or someone in your family suffers from frequent colds/flus, a juicer is a worthwhile expense (and of course it has many other uses).


  • Juice (or grate on a fine setting) 1–2 pounds of ginger; place juice in a jar and refrigerate
  • Place 2–4 ounces of ginger juice in a mug with the juice of one-half lemon and a large tablespoon of honey (honey is also anti-viral). I recommend Beekeeper’s Natural honey. Add 1/8 teaspoon of cayenne pepper and 6 ounces of hot water.
  • Drink 2–6 cups of this a day, sipping slowly throughout the day

#3: Wash Your Hands

Maybe you already know this, but studies have shown that frequent hand-washing is one of the most important things we can do to protect ourselves during cold & flu season. Wash your hands every time you arrive at a destination while out and about, and first thing when you get home.

#4: Take Elderberry Syrup

Elderberry is one of the most effective botanicals for strengthening immune function and preventing colds and flus. Take 1 teaspoon twice a day if you feel like you’re coming down with a cold or flu—and continue taking it if you do get sick.

#5: Take Immune-Boosting Herbs

There are several botanicals that have a potent immune-boosting effect. I recommend the following blend for prevention during cold season:

  • Mix equal parts astragalus, cordyceps, and rhodiola in tincture form. Herb-pharm is my favorite brand.
  • Take up to 1/4 teaspoon 3x/d for prevention, and 1/2 teaspoon up to 6x/d if you’re already sick.

Note: since astragalus, cordyceps, and rhodiola are “immune boosting” botanicals, people with autoimmune diseases that involve an overactive immune response should exercise caution and speak with their health-care practitioner before using them.

#6: Take Anti-Viral Herbs

If you’ve finally succumbed to a cold or flu despite your best efforts, there are a number of anti-viral herbs that can be helpful. If you want to go deep on this topic, I strongly recommend Stephen Harrod Buhner’s excellent book, Herbal Antivirals: Natural Remedies for Emerging & Resistant Viral Infections. But if you just want to cut to the chase, here’s the formula he recommends for treating mild influenza and colds:

  • Mix 2 parts lomatium, 2 parts red root, 2 parts licorice, 1 part isatis (all in tincture form).
  • Take 30–60 drops mixed with 1–2 ounces of water each hour until condition improves. You may have trouble finding some of these botanicals locally, but you can get them fairly easily online.

#7: Rest

Of all of the recommendations, I suspect most people will have the hardest time with this one. In our crazy, hectic world, rest is simply not valued—but it’s absolutely necessary when battling a viral infection is consuming a lot of your energy.

Of course it’s not always easy to take time for yourself, especially if you have young children (I know this firsthand!), but even a few short rest periods throughout the day can make a big difference when it comes to supporting your immune system.


Join the conversation

  1. I don’t get colds, but have read that massive doses of vitamin D for 3 days in a row, at the first sign of a cold coming on. I have had reports of good results from this.

    The dose of vitamin D to treat a flu is about 900IU per pound of body weight (2,000 IU per kilogram). The dose would be taken once a day for three days; that’s about 135,000 IU a day for a 150lb. adult.

    • Lol!

      The dose of vitamin D to treat flu is …

      Really? You’re acting like this is a science. There is no “dose to treat flu”. It would depend if the person is vitamin D deficient, their weight, and Many other factors. And that’s assuming that it actually works in a person who has a regular daily supply of vitamin D and isn’t short on it.

      I’m all for nutrition to stay healthy, which includes lots of vegetables and nutrient rich foods along exercise. But some of the claims randomly being thrown around this site are ridiculous. Sure vitamin D is awesome, so are many other nutrients. I don’t think we have any evidence showing that people with adequate stores of vitamin d do better after having the flu. Obviously deficient individuals will do better. But they would do better with all kinds of vitamins and even regular exercise.

  2. AHCC (Active Hexose Correlated Compound) , Beta Glucan, oil of oregano, olive leaf extract and propolis are also good for stimulating the immune system.

    I plan on using mastic gum, olive leaf extract and oregano oil to fight H Pylori infection if tests come out positive. I may take them anyway, since blood tests can miss detection if you’ve had H Pylori infection for a long time.

    • @pm
      My husband got rid of H Pylori using mastic gum, chewed a piece daily in the morning on an empty stomach for about 30 minutes and in the afternoon between lunch and dinner. He did this for about 6 weeks along with a semi Paleo diet and it could no longer be detected,

      • That’s encouraging to hear. Six weeks is a lot longer time than antibiotics would take, but much much safer — which his the whole point, right? Thanks for letting me know.

    • I got rid of an h. pylori infection with something similar. I followed one regimen for 3 weeks, then switched to a second for 3 weeks, then back to the first for 3 weeks, and finally the second for 3 more weeks. It took 12 weeks but the infection disappeared without any need for antibiotics.

  3. ZINC all the way!! It works magic. I can’t believe Chris didn’t mention this. While I hate to mention brand names, Zicam lozenges, when taken exactly according to the package’s directions, prevents most colds for me. It must be taken at the first sign of a cold, however, to be most effective. I start taking it as soon as I feel a sore throat coming on (which is how my colds start most of the time) and within 24 hrs I am symptom free. In the rare cases that a cold ensues, it is a much much milder version of the colds than I used to get. My daughter can’t stand the lozenges, but I find that giving her zinc tablets to swallow (combined with echinacea) is almost as effective.

  4. Also, Standard Process supplement, Congaplex is fantastic, take 2 capsules per hour at first signs of cold!

  5. Let’s not overlook the value of homeopathic remedies. Hyland’s makes a wonderful product called Cold Calm and for flu you can’t beat Oscillococcinum. I’ve had wonderful results from homeopathy and it sure beats swallowing a handful of pills everyday.

      • I wouldn’t believe anything from wikipedia or wiki anything. You need to find a different reference if you want me or anyone in the know to take you seriously. Otherwise, you are simply viewed, IMPO, as a troll.

      • This negative comment about homeopathy is such a strike against my normally positive or neutral response to these articles. My evidenced based response as well as that of my family (who actually don’t believe in them, even though they can stop a vomiting episode within minutes) refutes your condescending link. If I’m trusting in evidenced based zinc or elderberry, return the respect for evidenced based CORRECTLY USED homeopathy.

        • I don’t think it’s condescending to acknowledge that peer reviewed studies haven’t found conclusive evidence that homeopathic remedies work. Wikipedia links to these studies, and many people when using wiki as a source in comments do it in lieu of linking to all those studies separately.

          I’m sure most people just want safe, easy, and proven ways to deal with illnesses, but to figure out what those are, we need to weigh the evidence for and against treatments. This goes for all treatments, not just homeopathy.

          Anecdotes don’t really constitute evidence, because someone else has another anecdote saying the opposite. So who’s right? Determining that is what science is for.

          High quality peer reviewed evidence will tend to get more respect than a random person’s experience, because high quality scientific studies are designed to control for all the confounding factors that can affect illnesses and confuse the issue of whether a treatment is actually effective. So it’s only fair that peer review science will get more respect than a person’s anecdote, right? That doesn’t mean your experience isn’t important, it just means it’s an n=1 that can’t be generalized to others.

          People will have to weigh scientific evidence against anecdotes themselves, but it’s always helpful to check different lines of evidence either way. I always check both to get a complete picture. Though I have to note that what’s particularly pertinent in homeopathy is lack of mechanism.

          • Agreed. Homeopathy is well known to have no scientific background, no double blinded placebo controlled studies and just piggy backs on the placebo effect.

            • Craig, besides my response above, which I am not sure they will let post as it goes against big money, and your placebo defense of it, I think a placebo is a great thing when nOT dealing with major illness, especially something like a common cold.

              I would much rather find a nice, cheap placebo concoction that works for me in fighting something like the common cold, instead of spending a bunch of money lining the pockets of pharmaceutical companies with a product that despite a few hundred profit motivated ‘scientific studies’, doesn’t work for me, and also opens up the chances for a terrible side effect.

          • I put more weight in anecdotal evidence because it is usually first born from many uses in the past, while the scientific had big money clouding things up, and that same big money will push to dismiss homeopathic (almost never pouring the same amount of money into it because it’s too cheap to produce) and will have a bias in favor of where money can be made, which also leads to ignoring signs of ineffectiveness of non-homeopathic medicines.

  6. Propolis is a great one for my family, also seems to track sore throat in it’s tracks. Vit C, Echinacea and homemade elderberry syrup are the other winter “staples”.

  7. For up coming flu I’ve found that taking more deep breaths, getting more oxygen in the body, stimulates the lymph system and makes the flu go away soon.

    Also rubbing your self or getting rubbed by some one close gives an tremendous immune booster, so cuddling is good besides keeping warm.


  8. I have found that using a combination of liquid herbs of
    echinacea,olive leaf,astragalus,sambucus,thuja,colloidal silver,base as in The Pot Lots immun/virus formula works well

  9. Fire cider/Master tonic every couple of hours works for me. I added echinacea tincture for extra punch! I gargle and breathe it, then swallow.

  10. Hi Chris!
    I have a special needs child and I have been giving him liquid Cod Liver oil, for kids. I didn’t know fermented was key until after I purchased it. My son is super picky. What is the best liquid form for kids?

    • Green Pasture is a good brand, as is EVCLO (EVCLO.com). It’s not key that it’s fermented; the main issue is the vitamin content. Both of these brands are high-vitamin.

      • There was recently some discussion (in the comment section especially) over at David Gumpert’s blog, The Complete Patient, about the dangers of using fermented cod liver oil.

        Everyone is entitled to their opinion, however, so one must do what one thinks is right. But you need to have all the facts before you do these things. Too many opinions these days on things like CLO and other “health” foods/supplements/options.

  11. Hi Chris,
    Nice article, I really enjoyed it. I would like to recommend virgin coconut oil intake, it’s the best bet one could do for shortening cold and flus!

    • Agree, Silvio, and I would add:

      I apply coconut oil topically (instead of lotion) after I wash my hands and throughout the day. I keep a small bottle of top-quality coconut oil in a recycled cod liver oil bottle in the center console of both our cars so that we can always make sure our hands are clean, even if soap/water aren’t available. I used to get sick much more frequently than my husband, but I haven’t caught even a sniffle after he brought home a cold last month and late last winter.

      I can attest to its anti-viral properties firsthand since it vanquished a cold sore in 48 hours flat (compared to 12+ days with Rx Denavir). Powerful stuff!

  12. Very opportune information, thanks very much!

    I’ve always struggled my entire life with frequent and very severe colds that knocked me out for the better part of a week. But I have noticed a drastic improvement since I eliminated omega-6 rich oils, excessive sugar, and wheat products from my diet. I also eat a lot of apples and other whole fruits, and I drink lots of raw milk. As far as vitamins, I occasionally take most of the ones mentioned in this article.

    A question about vitamin C… what exactly is Liposomal Vitamin C, and how does it compare to say, regular vitamin C with rose hips? And what about Ester-C? Any advantages, or is it a farce?

  13. I was surprised to see Vitamin C mentioned I thought this cold remedy had been thoroughly debunked. I tried it for years to no effect.

    However echinacea works a treat as long as it is a good quality one and not the liquid form

    • Vitamin C fuels the white blood cells. Echinacea stimulates an immune response against the infection. Most people will do better by taking both vitamin c and echinacea. You probably have adequate vitamin C, but lack the immune response.
      People with autoimmune problems should avoid echinacea.

  14. Chris, what do you think about taking N-acetyl cysteine for the flu (and maybe colds?) I seem to remember reading that it might be useful to fight the flu… and I suppose it’ll at least help your body detox if you end up taking cold / flu symptom relief products with acetaminophen.

    I also find Pelargonium sidoides tincture to be useful for colds especially when it’s working into my lungs.

    • NAC is a glutathione precursor, and glutathione can definitely help with viral and intracellular infections. There are about 10 other tips I could have included here (tried to keep the article a manageable length), and glutathione is definitely one of them.

      • Pure Encapsulations sells liposomal glutathione. Is this better than NAC and what amount is recommended for infections?

  15. Wish I’d seen this article a month ago, when I went down with a bad flu. It took weeks to fully recover, particularly from the fatigue. I hadn’t been eating much meat during my illness, so last week I started eating a little liver each day. The boost in my energy level was immediate!

  16. I love to drink lemon water in the morning before breakfast. One half or whole lemon squeezed in warm water. Makes me feel great, boosts my immunity and gives me energy for the day.

    • To avoid acid damage to your teeth (I speak from experience!) and immediately raise the PH level in your mouth to 7.0, be sure to do one of the following for 4-5 minutes:
      1. swish 1 gram (1/4 tsp) of 100% xylitol granules
      2. chew 100% xylitol sweetened gum
      3. let 100% xylitol sweetened mints dissolve in mouth

  17. Hi Chris,
    Love your work. A great addition to the ginger tea that I’ve found works really well is to place garlic cloves and quartered brown onion into a big jar of honey (as much as you can fit in) and leave overnight. The active constituents of the garlic and onion steep into the honey, and you can strain the vegetable matter out once complete. You’re left with a much thinner consistency garlic/onion honey syrup that can be spooned into the tea for added anti-microbial effectiveness.
    Keep up the great information – you’re an inspiration to all us practitioners!

    • In regards to the Ginger/lemon/cayenne pepper/honey drink. I know you mention that it’s difficult for some people to withstand because of the intense flavor of the Ginger but what about the Cayene pepper? I found it difficult to over come. Would it still be effective if I put less Cayene pepper in it? What role does the Cayene pepper play in it?

      • Brandy, for what it’s worth, I add a few shakes of cayenne pepper to my morning lemon-water drink, and it took no time to get used to it. Now, on the rare occasion that I forget, I actually miss it!

        The heat is, yes, shocking when you’re not used to it, but as I say, the shock doesn’t take long to wear off. Maybe you can start with a shake or two of the cayenne , and increase it every few days until you are up to 1/8th teaspoon — which really isn’t very much.

        Hope this helps.

        • Hi Carsie! Yes I completely agree. I am actually having a cup as we speak and I put just a couple of shakes in it. 1/8 teaspoon was definitely a shock but I’m working my way up to it. 🙂

      • Brandy, another thought about the cayenne pepper….If, instead of adding it to the basic mixture, if you add it just before drinking the tea, the cayenne doesn’t heat up the mixture too much before you drink it, but yet you get the benefit of getting it into your system.

        • Thank you Norma. I did try it again where I didn’t heat the drink with the Cayenne pepper in it. I do agree that the heat isn’t as intense