Supplements for Colds & Flu

Do any supplements help for flu?
Reviewed and edited by Tod Cooperman, M.D. Tod Cooperman, M.D.
Initial Posting: 12/10/2014    Last Update: 10/24/2019
Supplements for Flu -- women with the flu sitting on couch with tissues, thermometer, warm drink
If you are deficient in vitamin D (with a blood level below 20 ng/mL), increasing that with vitamin D supplementation may help prevent the flu as well as other upper respiratory infections.

There is preliminary evidence that ginseng may help reduce the chance of flu infection and increase the effectiveness of the flu vaccine. NAC (N-Acetyl Cysteine) taken daily during flu season has been shown to significantly reduce the symptoms of flu, although not its occurrence. Elderberry has also been shown to reduce the severity of flu symptoms. (Although rare, be aware that a case of acute pancreatitis was reported in 2019 in a 51-year-old man after he took two to three doses of elderberry extract (Sambucol)).

Preliminary clinical evidence suggests that a branded ingredient produced from the fermentation of "whole food" by brewer's yeast (EpiCor) may modestly improve certain measures of immune function and slightly reduce the incidence of flu symptoms.

Although zinc, garlic and echinacea may be of some help with colds, there is little evidence that they help with flu.

CBD (cannabidiol) oil is sometimes promoted to treat colds and the flu; however, there do not appear to be any published studies on the effects of CBD supplementation for these uses.

For more information about these supplements, use the links above. Also see the Encyclopedia article on Colds and Flus.

Learn More About Immune System Health:

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Is it true that NAC can help clear nasal passages? >>

Do any supplements help prevent or treat a cold? >>

What is EpiCor? Does it really "boost" the immune system and prevent colds? >>

What is monolaurin? Can it really prevent colds, cold sores, or other infections? >>

Is Esberitox effective for treating a cold? >>

Can green tea help prevent the flu? >>

A tea called Throat Coat made me lethargic and I was found to have low potassium. Is this a known problem? I was drinking 5 cups a day. >>

Does CBD help fight colds or the flu? >>

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harold jitschak19186   March 15, 2020
Also -like former years- I saw and see spectacular very fast results [better the next morning!] with tincture of Portulaca in cases of flu [it maybe even that there were cases of Corona between them but I have no proof for this as I advise to start portulaca straight away in any case of "flu symptoms"
Sometimes the portulaca was combined with esberitox [by people who had this at home as well]
Many hundreds of patients have bought portulaca and I can't be that mistaken [for so many years]
If I knew how to attach a PDF I would like to do so to show you why I  based my decision to use Portulaca for flu since the last swine flu in 2009.
It is a pity that it is not being tried by others as well.
I hope full heartily that you may help spread the message.
I have whatsoever no other interest in this than to see that an easy cheap method may help so many.

micheline17894   June 2, 2019
I have problems with methylation (MTHFR) and NAC is helpful but it's very hard on my stomach. I take Doctor's Best, it also has some molybdenum. Not sure what to do. I ordered some glutathione but really like NAC.

Tom19067   February 5, 2020
There are methylated folic acid and b12 for people with MTHFR. There are multiple brands that carry the methylated version. I'm not sure that the one you are taking carries it though.

Ruth16366   January 24, 2018
As a 73 year old woman who has been very susceptible to flu and colds my entire life, I have found some things that work well, especially if I start them as soon as I feel unusually tired, achy and head achy and if I start to sneeze or get a scratchy throat. And during times of high exposure I use them as a preventative.
I use silver sol, which is more effective than colloidal silver.
I add it to a bottle of water to which I also add a generous amount of elderberry. My favorit is the Vitacost brand as it is stronger and not cloyingly sweet. I sometimes also add some Fungi Perfecti immune boosting mushroom tincture. I keep a bottle of this with me throughout flu season and sip it through the day, especially if I go out in public or know I am exposed to someone who is ill. When I am vigilant using this and other supplements like olive leaf extract, Vit C, Vit D, oregano oil, and eating coconut oil (also anti viral) I do OK. I also have the silver sol in a little pump spray bottle and another nasal spray bottle for nose, throat and eyes. This year I had a little scare with a possible cancer and began drinking Essiac Tea along with my morning green tea. I learned that it is good for more than cancer and some take it as a preventative.

marjorie16365   January 24, 2018
Been using the following successfully for years, even with our restaurant workers who work closely together in a warm and moist kitchen where infections spread like wildfire. The only person who went down was our chef who refused to use any supplements!
Purecaps Thymuplex
Vit C
Zinc lozenges
We start by doubling up dose for a couple of days (and all night, if possible) every four hours. When symptoms are under control, we drop to normal dose every 4 hrs. We find that even if the symptoms are eliminated, it's necessary to continue on diminishing gradually or the infection will come roaring back.
Absolutely incredible. Now retired, I never travel without the combo and often find I need it.

Terri16359   January 21, 2018
I have had great success with Ocillicoccinum at first sign of symptoms. Sublingual. If the first dose doesn't fix it, I do it an hour or two later, as well. It puts me to sleep and when I wake up I feel much better. Must use half hour before eating, or a couple of hours after. A helpful prevention is to take half a vial a week for 6 weeks at the beginning of the flu season,   January 23, 2018
Thank you for sharing your experience with this Terri. Information about Oscillococcinum can be found here:

MaryJo16357   January 21, 2018
My husband and I are almost 80 and take no medicine, except Armour thyroid and bio-identical hormones. We also take vitamins, feeling Vit. D is vital and contributes to our great health! We have not taken the flu shot for years (have had arm pains since last shot??) and just increase our D during flu season. Our research shows and our doctor recommends at our age our Vit. D count should be between 50 and 70 for optimum health. We have not had the flu or any colds for years now!!! Hopefully more doctors will become aware of the power of this little vitamin, have all their patients take a yearly Vit. D blood test, and recommend taking this essential vitamin. I know the prescriptions of drugs will decline! What a gift that would be for all!!!! (When we used to get sick, we always took Sambucol right away which worked!)   January 26, 2018
Hi MaryJo - Thank you for sharing your experience with this.

Please note that research suggests vitamin D supplementation is effective in reducing the risk of respiratory infections (including certain types of flu) in people who do not have adequate blood levels of vitamin D, but there are risks associated with blood levels higher than 50 ng/mL

Pamela16410   February 3, 2018
Mary Jo: Congratulations on taking such good care of yourselves so that you have not had colds or flus for years and on no meds at age 80. I would love to know you foods and lifestyle habits to contribute to this. Thanks

Letcher11512   December 15, 2016
I have been taking vitamin C (500-1000 mg) zinc (50 mg) NAC, glutathione, oil of oregano (last two, more recently) for years, and I haven't had a cold OR influenza for almost 30 years. I had my first flu shot this year (test) and I noticed it increased inflammation of my joints and a strange rash on my hand.....won't be inoculated again.   December 15, 2016
Thanks for sharing your experience. Glad you've been cold-free for so long. Be aware, however, that the RDA for vitamin C is only 75 to 90 mg. Getting extra vitamin C (500 to 1,000 mg) from a supplement has been shown to increase the risk of cataracts, as noted in the Vitamin C Supplements Review at Ingesting too much zinc (the upper limit is 40 mg per day) can interfere with copper absorption, as noted in the Zinc Supplements Review. You only need a small amount of zinc (8 to 11 mg) per day to maintain a healthy immune system and zinc's cold-fighting property is otherwise limited to its use as a lozenge where it can work directly on the throat, as also explained in the Zinc Review at

Larry16367   January 24, 2018
Commenting on Letcher 11512's remarks about a strange rash after the flu shot this year. This happened to me also~! First time ever, and I've had flu shots for about 45 years. A couple hours after the shot I got a burning sensation in the middle-finger area of my left hand and the joint swelled (as with angioedema)~! Lasted a few hours and I could barely use it. Felt hot with a red surface rash. Anybody else experience this???

John11510   December 14, 2016
I'm amazed that vitamin D has not been mentioned. My wife and I both experienced flu-like illness every (every!) February from the mid-90s through about 2005, when I learned about vitamin D. Taking enough D to keep our 25(OH)D levels around 50 ng/mL has resulted in NO flu-like illness since, in fact we have hardly any minor illness at all any more. We stopped taking flu shots about five years ago.   December 14, 2016
Hi John - Thanks for sharing your experience. You are correct that vitamin D can be helpful, particularly when correcting a deficiency (blood levels under 20 ng/mL). We have added that information to the answer. However, this benefit may be reduced or lost when boosting levels too high -- such as in the high 40's. It's great that you've been flu-free, but there are potential disadvantages from maintaining a level in the 50's. This is discussed in the Vitamn D Review at
and in the section at

John11506   December 14, 2016
I've had really good success with Sambucol for symptom relief and shortened duration of colds/flu.

Dennis8177   December 10, 2015
I have not had a viral infection for over three years. Quite an accomplishment for a guy who normally got 3-4 colds a year plus bronchitis every couple of years. The answer is Glutathione, the body's master antioxidant. Add some liposomal Vit C and you're really protected.   December 11, 2015
Hi Dennis - Thank you for sharing your experience with these supplements. You can find more information about glutathione in the Encyclopedia article ( and the Review of Protein Powders and Drinks ( ). You may also be interested in this CL Answer about liposomal vitamin c:

Michelle 8174   December 10, 2015
Yin Chiao has proven to be effective, especially when dosing begins at the first symptoms of illness. Both severity of symptoms and length of duration have shown to be lessened through use of Yin Chiao, which is derived from Honeysuckle flower.   January 3, 2016
Hi Michelle - Although Yin Chiao has traditionally been used for this purpose, we are only aware of some preliminary research (, not studies in people. For information about other Traditional Chinese Herbal Medicines, including those for colds and flu, see the Encyclopedia article:

Hanna8170   December 9, 2015
We use a product called Flew Away by Natura. it combines. Elderberry, Propolis Gum, Forsythia, Honeysuckle, Elder, Ginger and other ingredients to provide robust immune support and can also be used to lessen the duration and severity. This is our personal experience. Some of the herbs in this combination match up with recommendations from Chinese medicine.

Carol8168   December 9, 2015
I have taken generic equivalents of Airborne before I fly and Zicam at first sign of a sore throat. I follow the directions until the sore throat goes away--about a half day or day. Haven't been sick for many years. I just don't ever get the flu. Just lucky I guess.   December 10, 2015
Hi Carol - Thank you for sharing your experience with these products. Please be aware that there may be adverse effects with certain forms of Zicam. See the "Concerns and Cautions" section of the Zinc Supplements Review for more information:

Larry8165   December 9, 2015
Elderberry extract has some evidence to shorten the length of influenza from 6 days to 2 days. Regular use during flu season may lower risk of contracting influenza.

J Altern Complement Med. 1995 Winter;1(4):361-9.
The Journal of International Medical Research 2004; 32(2):132 - 140;
OJPKTM Online Journal of Pharmacology and PharmacoKinetics, Volume 5: 32 - 43 2009   December 9, 2015
Thanks Larry! For more information, see the Encyclopedia article about Elderberry (linked to in the answer above) which discusses two of these studies.

Barbara8163   December 9, 2015
I agree with Barbara304 and Beth308, that Echinacea and/or Oscillococcinum help when I take them at the first sign of a cold or flu, I prevented getting sick several times. Both help redusing symptoms for me too.

Peter8161   December 9, 2015
I have taken ginseng in the past, and it interferes with my sleep. Not sure if that is a know side effect or not.   December 9, 2015
Hi Peter - There are reports that high doses of ginseng can cause over-stimulation or insomnia; also be aware that some ginseng products promoted as boosting energy may have added caffeine, so always be sure to carefully read the label. See the "Concerns and Cautions" section of the Ginseng Supplements Review: and the Encyclopedia article on Ginseng for more information:

Peter8164   December 9, 2015
Thanks for the added information. I'll be sure to check it out.   December 9, 2015
You're welcome!

jeff8158   December 9, 2015
I am taking monolaurin lauriciden to prevent the flu. Also prevents cancor sores.

Franco16358   January 21, 2018
Since I started taking monolaurin (in Lauricidin form) three years ago, I have not had the flu once, and only the mildest of colds; and the big test has always when traveling to Europe during the winter, which always gave me the flu or something like it. I know there scientific studies are “preliminary,” but I would like to register my own positive results (with no side affects).   January 31, 2016
Hi Jeff - Thank you for sharing your experience with this supplement; however, the evidence for these uses appears to be very preliminary. Please see the CL Answer about this:

Susan8153   December 9, 2015
I have used Astragulus and Andrographis for years and have not gotten the flu since 1984. There are also many other things you can do to prevent the flu, such as regular chiropractic care (increases immune response), moderate exercise, eating a diet rich in phytonutrients, sunshine, stress reduction....

William8156   December 9, 2015
There is zero scientific evidence that chiropractic care increases immune response, none

John8160   December 9, 2015
There's plenty of studies that do show that regular adjustments boosts the immune system significantly. Below is a link that corroborates this information.

ron8151   December 9, 2015
For the past 2 years or so I have a healthy smoothie every morning for breakfast and I have avoided any sickness at age 81. I do get the flu shot.

Jerry8150   December 9, 2015
Another homeopathic product for flu prevention is Influenzinum. It is a homeopathic preparation of the same flu strains that are in the current year's flu vaccine (3 strains). According to the homeopathic literature, this product has been used successfully for decades and has been very effective in preventing influenza. I don't know if there have ever been double blind clinical studies to demonstrate the effectiveness of the product. So the reported effectiveness may be more anecdotal.

Beth308   December 11, 2014
I have found that a flu product from Boiron company called "Oscillococcinum" has prevented me from getting the flu multiple times. It has to be taken, however, at the first sign of a symptom.
For colds, I have found that "Cold Calm" from the same company, Boiron, has prevented me from getting colds. Again, it must be taken at the first sign of a symptom.   December 11, 2014
Hi Beth - More information about oscillococcinum and clinical studies of its efficacy are in the article on at

Pattie8159   December 9, 2015
I too have had multiple positive experiences avoiding the flu or getting less symptoms than my family/friends when taking oscillo. This coming from a person who used to get flu the worst of anyone I came in contact with.

Barbara304   December 10, 2014
Echinacea halps me if I take it at the first sign of a cold or flu. I prevented getting one several times by taking echinacea when I first feel body ache and/or start sneezing and feel like I am getting sick.

Dennis303   December 10, 2014
The Life Extension Foundation offers a common cold protocol ( The last page of the 7 page article lists the recommended supplements and gives dosing instructions. It's important to start the protocol at the early onset of symptoms. I used this protocol for eight years and managed to avoid bronchitis which has plagued me since childhood. The protocol was formulated by the founder of Life Extension who claims he has not had a serious cold in 20 years.

Another, simpler protocol involves daily administration of oral Glutathione (Setria form). Glutathione (GSH) is the body's master antioxident and serves to help prevent viruses from attaching to cell walls. Along with GSH (500 mgX2 on an empty stomach) take a lyposomal form of Vit C and a B complex. The person who got me started on this protocol has been on it for years and also claim to not have experienced a serious cold. I have been on the protocol for one year, experiencing only minor sniffles.

Lucy Diana300   December 10, 2014
I have taken elderberry for years in the winter, and I never get flu even though I never take flu shots.

STELLA 294   December 10, 2014
Ginseng makes my BP go up.

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This CL Answer initially posted on 12/10/2014. Last updated 10/24/2019. members may submit questions to We read all questions and try to answer those of popular interest.



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