7 Tips for Preventing Colds and Flus | Chris Kresser

7 Tips for Preventing (And Shortening) Colds and Flus


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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. 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 received a post on FaceBook yesterday from Charles Poliquin. He is a strength coach who has trained many NHL, NFL, and Olympic Athletes (over 100 medal winners).

    When his Olympic athletes get sick get sick before a meet he has a three-step protocol that he uses that cures them in 6 hours:
    Step 1: Take 10 grams of Glutamine every hour
    Step 2: Swab your nostrils with rubbing alcohol – this will sting a bit – it’s to kill any bacteria in the nostrils
    Step 3: Gargle for 30 seconds with warm water and sea salt – this kills any bacteria in the throat.

    He says all symptoms will be gone after 3 hours, but to make sure they don’t return this should be continued for 6 hours.

    • Sorry, there was more step. That is attitude. He said that the brain is hard-wired into the immune system – that’s why people with high-stress levels get sick. Keep a positive attitude and don’t give any negative thoughts towards being sick.

  2. Whenever I need to drink something unpleasant I keep up the swallowing action as I finish it and quickly continue with plain water to rinse away the taste. Hope this is helpful.

  3. Wow! I can’t believe you left out HUMIDITY. Dry indoor air during the winter time is a major cause of cold and flu infections.

    We tend to forget that the primary immune barrier is physical: skin and mucous membranes. When the lining of your nose and throat become dried out, the immune barrier is breached, allowing nasty viruses to invade.

    In my experience, almost every cold and flu I’ve had started with a sore throat, possibly from sleeping with my mouth open in a low humidity environment.

    I know it’s anecdotal, but since installing a quality whole house humidifier, no one in our home has come down with a URTI.

    • agreed! didn’t have a humidifier recently. i noticed my skin was super dry and my hair was extremely static for days. then a week later i get a nasty cold.

    • He probably left it out because in the Bay Area we struggle with high humidity and mold in the winter. If used a humidifier my house would be overrun with mold.

    • Me too! I more or less followed the recipe Chris wrote out, except that I substituted homemade chicken broth for the hot water.

      I simmered it in my crock pot & drank it all day Sunday, and obviously this is anecdotal, but I feel pretty good today.

  4. Amen to all of your recommendations! I also take oscillicoccinum at the first sign of flu-ish symptoms. And rest is absolutely crucial! I was coming down with something nasty right before Christmas and made time to nap for an hour and a half two days in a row. That along with Oscill and my homemade echinacea tincture beat that cold/flu into submission. I felt great throughout the holidays, PTL! Stay home from work and get well.

  5. Chris,

    I tried this in earnest last week and it worked. My kids (ages 9 and 8) had both been sick with nasty colds, the kind with plugged noses and heavy congested coughs. After spending the long Thanksgiving weekend in close quarters with them I started to feel ill on Monday. I started with the ginger treatment but added garlic and lots of cayenne and also yellow onion and instead of juicing I pulverized with food processor and then added a tablespoon or two to broth and sipped that throughout the day. I also took extra zinz, maybe up to 400 mg. By the next day the symptoms had become minor but I decided to do the full on ginger formula that you recommend and I juiced it this time. Sipped that throughout the day and also got a vial of black elderberry from Whole Foods and took a couple of teaspoons a day. If I truly had a cold, and I think I did, this lessened the length and severity by at least 75%. Incredible. It made this cold into a minor annoyance. I will definitely continue to do this at the first sign of illness.


  6. For using the neti pot, I know you use distilled water. Is it ok to use the water from the dehumidifier for the distilled water? Is it safe or should I just buy it at the drug store?

    • I know that this is a half a year after, however, I thought I’d add this info for next year. 😉

      Dehumidifiers are notorious for collecting mildew spores and also the waste reservoir is often made from recycled, NON-food safe plastics and cannot be counted on to be as clean as a food-grade condenser.

      I hope that this helps.

  7. I’ve had a cold for over a week and I’m just seeing these tips but they sound great! I do take the FCLO but I must admit that I ran out 2 times this past year and that’s when I got sick: first with shingles (fairly mild) and now with this bad cold. Could be coincidence but I’m going to make sure I don’t run out again! Thanks so much for all the great info you share! I really appreciate it. I have your book which I also gave to 3 family members!

  8. I’m a little disappointed that you are giving all this immune boosting advice but the only thing you warned against with regards to autoimmune disease are the immune boosting herbs. Anything that boosts the immune system has the potential to exacerbate or flare up symptoms in people with autoimmune disease. I can’t even take vitamin C without it flaring my symptoms. Many of us with autoimmunity follow individuals like you, among others, for advice because regular medical professionals just don’t get it. If I hadn’t already known this through personal experience and tried what you’re recommending, I would be upset. Please be thorough in the future…Ibtrust you know better.

    • Thank you! I had been wondering that myself… I have Rheumatoid Arthritis, and it’s pretty close to remission, I really, truly do not want to endure my RA coming back full force!! Thank you Casey!

    • I used to have this issue, even thought i had developed a garlic & onion allergy! Basically my life was being ruined by Lupus for many years, everything made me sick even the drugs to “help” & I was getting worse with kidney failure! Then I did GAPS protocol & cured all my symptoms by healing the gut lining & inner ecosystem of gut flora. Autoimmunity is caused by a leaky gut and a gut healing diet like GAPS can cure it for FREE at home. I think Chris kresser discusses this but these natural doctors have a tendency to over complicate it in my opinion so you Feel you need to pay For professional help. If you are smart this is not hard to do on your & doesn’t generally require supplements. Supplements & herbs as you noticed can be very bad for people with a leaky gut who do not absorb & digest chemicals notmally. The Specific Carb Intro Diet guys give the intro that cured 99% of my symptoms within a few days for free as a pdf of their first chapter. i forget their names but Dr Natasha also gives the basic info necessary on her website gaps.me. If you don’t do the work to cure your autoimmunity you are looking at a young death from cancer. Like my mom who refused to look at any natural healing for her autoimmune condition & was dead from cancer by age 50. Once the immune system goes on auto attack cancer is inevitable. Watching my mom die such a horrible death is probably why I felt motivated to beat lupus when i got sick a year after she died.

    • Do you add coconut oil to your diet? (good source of lauric acid.) Also, one noted correlation between increases in sickness over the decades is the fact that fewer and fewer people drink full-fat cow’s milk and opt for fat-free. A huge mistake for many reasons, actually. Also, since fat is a nutrient transporter, it helps vitamin A be transported around the body, for instance. (Remember, “eating fat does not make you fat”.)

      • Leaky gut is why people are so sick in the west, and milk can be toxic for anyone with a leaky gut. Commercial dairy is genetically modified A1 protein , ultra pasteurized with synthetic vitamins re added & stored in plastics for a long time under fluorescent lights. Whole or non fat, organic or not isnt going to make a difference… commercial dairy has very little nutritional value & can exascorbate many mental & physical problems. Some people are more sensitive but for anyone with a health issue should avoid milk as it is very high in sugar & feeds pathogenic bacteria.

  9. When I feel that a cold is coming up (normally it starts in my throat) I take one teaspoon of Vitamin C (in form Sodium Ascorbate) three to 4 times a day (depends a bit on how I feel).
    This leads to a shortened time span where I have cold-symptoms (usually 2-3 days) and / or drastically reduced symptoms (subjectively I judge that symptoms are at least 50% less or more).
    While taking higher doses of Vitamin C definitely works (in my experience and clinical control trials), clinical trials show that – contrary to what Chris says – taking Vitamin C does not prevent colds.