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N-Acetyl Cysteine: A Warning Shot

I’ve highlighted several articles here over the years that cast doubt (to say the least) on the popular belief that Antioxidants Are Always Good For You. These other views do not seem to have penetrated the public consciousness yet, though, to judge by the way that foods and supplements are advertised. Today brings another example, and it vividly illustrates how the simple story gets things very wrong.

You would imagine that if any tissue is going to be susceptible to oxidative damage, it would be the lungs (where all that oxygen is absorbed in the first place). And indeed, such damage is seen as a component of many lung diseases, from COPD to various cancers. The antioxidant N-acetylcysteine has been widely used as a supplement in general (here in the US, you can find piles of it in the appropriate aisles of drug stores and vitamin/supplement stores), and it’s been particularly recommended for lung disease, both for its antioxidant effects and its ability to thin out mucus production.

Now, there are already data to suggest that that’s a problem. In mice with activating mutations in K-Ras or B-Raf, which are commonly seen in human lung cancers, antioxidants (NAC and vitamin E) actually seem to accelerate the growth of the tumors. That was reported in 2014, and you won’t hear much about it down at the drug store. Now there’s a study looking at not just growth of existing tumors, but tumor initiation itself, and the news is disturbingly similar. But it’s even more important to realize that (up to a point) NAC supplementation looks like it’s doing a lot of good.

This paper, from a multicenter French team, looked at three populations of aging mice: normal controls (+/+ for JunD), others that had had the JunD gene knocked out (-/-), and heterozygotes (+/-) who had reduced expression of the protein. JunD is recognized to regulate a whole suite of antioxidant responses in cells – Nrf2 is another example of this, and both of those have been found to be deficient (at both the mRNA and protein level) in the lung tissue of human patients with COPD.

Both the normal mice and the JunD-deficient ones got either NAC-laced water along with their mouse chow, or just water+vehicle as a control: a perfectly reasonable experimental design to assess the effects of aging, JunD levels, and NAC supplementation across each combination of these. And as each cohort aged, there were several interesting changes (which have been noted in some other studies as well). For example, JunD was upregulated with age in the mice who still had the gene, and its down stream oxidative-stress proteins (such as superoxide dismutase, Hmox, and others) increased as well (although not in the -/- animals, as you might have figured). Consistent with an earlier study from this same group, loss of JunD exacerbated oxidative stress in the lungs as the animals aged, as well.

Here’s the good part: the animals who got NAC supplementation really did show significantly fewer of those signs of oxidative damage in their lung tissue. It also reduced signs of cell senescence and overt histological damage of aging as well, such as emphysema lesions (all of these were markedly worse in the JunD knockouts, but NAC improved them as well). So far, so good, and this is exactly the case you’d make if you were pitching NAC as something people should take for healthy lungs as they age. But hold on.

None of the aged normal mice showed signs of adenocarcinoma developing in their lung tissue. But 10% of the aged normals getting NAC supplementation showed it. None of the aged JudD knockouts showed any, either, but 50% of the aged JunD knockouts getting the NAC supplementation had it. The best guess is that cell senescence pathway that seemed to be inhibited with the NAC: some of these are in fact cells that should have died and didn’t, and went on to become cancerous:

Our results therefore support a direct role for NAC in tumor initiation. This role seems independent from antioxidant gene expression, since opposite variations in antioxidant enzyme expression were seen in healthy mice and JunD–/– mice during aging. The protective effect of NAC against lung emphysema is an expected consequence of the decrease in lung senescent-cell accumulation. Altering the cell senescence process, however, may produce undesirable consequences, since senes- cent cells are well known to constitute a barrier to cell transformation and tumorigenesis.

Now that’s something to think about, isn’t it? It comes with the usual caveats about mouse models, but it ties in with the other reports that cancer is a complex enough situation that trying to prevent it (or treat it) with antioxidants is ill-advised at the very least. All of our cellular processes involve tradeoffs, and we’ve had a billion years or two for them to come into balance. Now, we may not agree with some of the equilibria we’ve reached, but we need to have a better understanding of all these checks and balances before we go in messing around with them. For example, I find longevity research very interesting indeed, and many of us would prefer to live longer than evolution cares about us living, but lifespan is a tradeoff between several other factors, too (one of which is the eventual development of cancer).

As for antioxidants, well. . .I’d say that taken together the idea that we can generally improve ourselves by taking them appears far too simplistic (to put things in their mildest form). It’s not that life has spent a billion years bumbling around not realizing that all that was needed was some extra vitamin E and N-acetylcysteine. Things are more complicated. They generally are.

83 comments on “N-Acetyl Cysteine: A Warning Shot”

  1. luysii says:

    The use of antioxidants in medicine has a checkered history. 25 years ago a trial of antioxidants (alpha-tocopherol and beta-carotene) in 29,000 people to reduce the incidence of lung cancer had exactly the opposite effect (an increase in the antioxidant group of 18%). The following subsequently appeared [ Science vol. 264 pp. 501 – 502 ’94 ] “In our heart of hearts, we don’t believe [ beta carotene is ] toxic” says one researcher. This is not science.

    This year another study (in an animal model) described a mechanism by which antioxidants ‘can also promote tumor formation’ — [ Cell vol. 178 pp. 265 – 267, 316 – 329, 330 – 345 ’19 ].

    For the gory details please see —

    1. MAURICE LEL says:

      And then you have other studies that suggest the opposite:

    2. DrLogic says:

      The question what is the minimum dose of NAC that is beneficial and how much is dangerous? In certain countries deemed “third world”, NAC is sold 200 mg per capsule/sachet. In countries like the US, they sell it minimum 600 mg and 1000/1200 mg per capsule. Use of NAC usually serves a particular purpose. It’s like vitamins, you can’t live without them, but you can’t also take too much of them. I like the article above, it’s good to warn people of the risks of taking supplements. So the French group who did the study can invest some effort in studying the amount of NAC that causes these dangerous outcomes, and come up with a guideline for safe consumption. The rule of thumb when consuming any medicine is to use the minimum safe and effective dose, not gulp as much as possible.

  2. Polynices says:

    “All of our cellular processes involve tradeoffs, and we’ve had a billion years or two for them to come into balance.”

    Very much this. I’ve often thought it’s sort of remarkable that ANY small molecule drugs (that aren’t antimicrobials or otherwise not directed at our own mechanisms) work at all. That antioxidants might not help isn’t too shocking from this way of thinking.

    Am I crazy to think this?

    1. Ian Malone says:

      Although you do have to remember that that evolutionary optimisation has gone towards reproductive success, not the longevity of individuals.

      1. Derek Freyberg says:

        True, but you have to live long enough to (a) have offspring, and then (b) raise them to the point that they are capable of looking after themselves.

        1. X says:

          I suppose a parent in a relatively primitive society could do that by age 40.

          So, evolutionarily speaking, we can all safely die at 40. Certainly by 60.

          Elders probably add some survival capability to groups (as well as potentially being a drag on their survivability in hard times), but…

    2. Dylan Richards says:

      Yes, “All of our cellular processes involve tradeoffs, and we’ve had a billion years or two for them to come into balance.”


      What were we eating when our bodies “came into balance”???? Our lifestyle and diet has changed SOOOO fast in the past hundred years, that maybe we need to rediscover what’s best for our bodies (e.g., pesticides, PFOS levels in water, BPA, processed food, non-seasonal diets, city vs rural microbiome, exercise levels…)

  3. bhip says:

    Whether or not antioxidants could help prevent a disease i.e. cancer, I suspect (naively perhaps) that what a really aggressive, metabolically active tumor really needs to be happy is a good antioxidant….

  4. Chairman Mao says:

    Its well established that decreasing ROS in immune cells causes decreased oxidative burst in them and their ability to phagocytose tumor cells and pathogens alike.

    A dirty little secret the supplement industry ignores while they have their heads up their asses.

    1. Deb says:

      Please, could you explain that in lay man’s terms for me. Much Thanks

  5. SA23 says:

    I am a biochemist working on aging and longevity research at a major university.

    There are some examples of ‘pure upside’ interventions that extend healthy lifespan with no tradeoff. These include: caloric restriction, autophagy enhancement, senescent cell ablation, and AAV-mediated telomerase expression. Lifespan has not been perfectly optimized. Indeed, there is little selective pressure to maximize healthy lifespan, because the power natural selection is strongest prior to reproductive age.

    Two evolutionary theories of aging cover this question: the Disposable Soma theory and the theory of Antagonistic Pleiotropy.

    This is the key review article in the aging field, ‘The Hallmarks of Aging’:

    1. ScientistSailor says:

      Caloric Restriction comes with the side effect of severe grumpiness.
      As for your other mechanisms, how do you accomplish them without side effects?

      1. Hap says:

        Caloric restriction means that the calorically restricted can’t do as much – everything (thinking, walking, etc.) requires energy, and if you don’t have the energy to spend, you can’t spend it. So caloric restriction isn’t exactly a free ride, either.

        1. Angi says:

          Ich meine, man bekommt eher mehr Energie durch Kalorienreduktion.
          Ich kenne viele Sportler die das durchziehen und die sind nicht im Slow Modus!

        2. Ed says:

          Keto diet allows for caloric restriction through intermittent fasting. I started the diet, not for a weight problem, but for a joint problem. Almost automatically it improved my joint aches to make them practically nonexistent, and in addition, I gained lots of extra energy with no spikes of highs and lows as in a regular carb/sugar diet. In the diet, you eat to satiation, and hunger takes much longer to return, so it is very easy to stay 16 hours and even 24 hours without food. Grumpiness also goes away when the spikes of sugar in the blood are regulated.

    2. DrLogic says:

      Yes, caloric restriction is the key for longevity and good health. So is maintenance of proper hydration and reducing stress. Chronic stress and inability to enjoy life, and sitting in front the computer and TV for 8 hours at work and 2 hours before sleep is crippling lifespans. As far as some of the comments here regarding “evolution” trying to get us to get some offspring and then we become useless, many of the major scientific contributions and wisdoms come from older generations, not just the young and eager.

  6. loupgarous says:

    “The protective effect of NAC against lung emphysema is an expected consequence of the decrease in lung senescent-cell accumulation. Altering the cell senescence process, however, may produce undesirable consequences, since senes- cent cells are well known to constitute a barrier to cell transformation and tumorigenesis.”

    This is something to think about for those of us who are impressed by the idea that cellular senescence is the bad guy and we ought to be winding our telomeres back to let us live longer. Maybe not.

  7. Red Agent says:

    Flipping channels, I just saw an ad for bottled water supplemented with antioxidants and another ad for bottled water with added oxygen, during the same commercial break. You have got to love the charlatans who come up with this stuff, and the suckers who buy it. I wonder if you wired these two concoctions together, maybe put out enough juice to charge an iPhone.

  8. Anonymous says:

    Previously posted In The Pipeline:

    Oxygen Radical Absorbance Capacity (ORAC). The US Dept of Agriculture used to maintain an ORAC table of various foods that would then be used by companies to hype their offerings to the hoi polloi. However, from the USDA … “In 2012 USDA’s Nutrient Data Laboratory (NDL) removed the USDA ORAC Database for Selected Foods from the NDL website due to mounting evidence that the values indicating antioxidant capacity have no relevance to the effects of specific bioactive compounds, including polyphenols on human health. … There is no evidence that the beneficial effects of polyphenol-rich foods can be attributed to the antioxidant properties of these foods. The data for antioxidant capacity of foods generated by in vitro (test-tube) methods cannot be extrapolated to in vivo (human) effects and the clinical trials to test benefits of dietary antioxidants have produced mixed results. We know now that antioxidant molecules in food have a wide range of functions, many of which are unrelated to the ability to absorb free radicals.”

    The USDA full announcement link no longer works: “page not found.” See wikipedia and elsewhere:
    “What Has Happened to the ORAC Database?”

  9. You better work !!!!!!! says:

    Idiots….,,I cannot wait until postdocs learn their lesson and just completely think it through that PIs are dumb.

  10. New student says:

    I need to be a prof now!!!!!!!!! I need respect !!!!!!!!! I need my own blog!!!!!! You better kiss my a)& as)(!!!!!!!!!!. I’m smart and I went to Avad

  11. Lane Simonian says:

    This might be one of those cases where you don’t want to throw the baby out with the bathwater. Certain antioxidants may help kill cancer cells because they become pro-oxidants. Other antioxidants may allow the immune system to detect and kill cancer cells.

    It is not a case of all antioxidants being a problem; it is a case of choosing your antioxidants wisely.

  12. gippgig says:

    One general principle of cell defensive mechanisms seems to be that turning them up a little is good but turn them up too far and you fall off a cliff. (Remember the p53 story? Overexpress it some and it reduces cancer. Overexpress it strongly & you get premature aging.) Try lower dosages of NAC. I’d be very interested in the dose-response relation.

    1. Nuketown says:

      It seams like you didn’t get the p53!!! Just stay away from antioxidants! Even when they say its safe in non cancer patients and fatal in cancer patients. PEOPLE HAVE CANCER LONG LONG TIME BEFORE IT GETS DISCOVERED!!!!!

  13. On the other hand, there are lots of other studies showing conflicting results. For example, one random study with human data shows that NAC might decrease markers of aggressive tumor behavior.

    It’s unfortunate that there are not more systematic reviews for basic/translational research such as this. This is a widely studied topic and reading too much into one individual study is not wise.

  14. drsnowboard says:

    I do have a problem with ageing being seen as a disease state and something to be cured. Who wants to live 50 years longer in the body of decrepit 80 year old? Are we really going to ‘treat’ healthy 25 year olds with supplements/ small molecules in the hope of preserving their youth into their 80/ 100s? That’s going to have to have a big old control group in the trial….

    1. kismet says:

      Of course you do, if you assume the conclusion. That treating, slowing or curing aging will increase the time spent suffering. What it will do in reality, is increase the time people spend being young and decrease frailty and suffering of the elderly. Will it also give you more years at the tail end? Sure, however, by that logic you could argue against any life extending treatment, like statins, etc.

      1. drsnowboard says:

        Yup, and people are already questioning the risk benefit ratio of statins for the ‘healthy’ patient population , those not carrying the risk factors of familial disease or previous MI etc.
        Ageing as a chronic disease to be treated is , in my opinion, too vague a syndrome.

    2. Chris Phoenix says:

      I know someone who lived to be over 100. She had osteoporosis. She also lived on her own until 96 or so, and made her own breakfast until a few months before she died. And she was sweet, intelligent, and creative.

      I’m a lot younger and healthier than she was when I knew her. But if I had a choice between dying next year, or living for 30 more years in the body and mind she had at the age of 90 or even 95, I would absolutely choose to stay alive.

      Aging isn’t fun (I’m almost 50 now), but dying is a lot worse.

      1. Nick U says:

        Our goal as humans is to Survive.

        Living should be our only goal period.

        1. drsnowboard says:

          The goal of any species is to survive. Once you are past reproductive age, you are not going to contribute to the genetic survival of your species, hence your long life is redundant.
          I’m not dismissing the value to society of elders in any way, being one myself, just saying no heroic efforts in which I include calorific restriction, believing supplement claims, taking prophylactic drugs from your 20s etc.

    3. Rod Spake says:

      I, being a healthy active 81 year old, take minor offense at you calling me decrepit.
      Pretty sure I could kick the ass of anyone over 50 I see in the gym. If I am ever allowed to go back to a gym.
      My hearing is not too good and I could use a new pair of glasses. Body overall is excellent.

      1. Keep it up, old-timer. You make us young guns proud!

  15. Cb says:

    Anti-oxidants with free thiol groups such as NAc-Cysteine, Glutathione and DTT (as present in your buffers!) are not always ‘save’ anti-oxidants because the molecular oxygen that is present (unfortunately needed for many living organisms) can be reduced to the more unfriendly hydrogen peroxide (what a paradox!) causing e.g. much damage to unsaturated fatty acids and biomacro-molecules. The formation of hydrogen peroxide can be catalyzed by numerous compounds catalyzing the redox reactions. As a medicinal chemist I deselected many of such false positive redox cyclers in screening campaigns on targets with sensitive thiols and when DTT is in the buffer. Oxidation sensitive targets (e.g. cysteine proteases) were not oxidized if instead of the anti-oxidant DTT a different anti-oxidant is used: TCEP, which cannot donate the hydrogen to molecular oxygen. So indeed it is tricky to generalize the benefits of anti-oxidants and perhaps too much thiols can lead to too much hydrogen peroxide in those organisms who use oxygen and in particular if they also biosynthesize/consume redox cyclers…………

    1. HTSguy says:

      Are you sure about TCEP not driving redox cycling? The experimental evidence says otherwise:

      1. Cb says:

        sure, but certainly examples where TCEP was better than DTT (and also Cysteine could be better than DTT)

    2. Barry says:

      In fact, anti-oxidants seem to block the benefits of exercise on longevity

  16. Barry says:

    Weiss wrote (“Tissue Destruction by Neutrophils”) thirty years ago that much of what killer T-cells do is mediated by super oxide, peroxide, and hypochlorite. Sopping these up leaves one (partially) immuno suppressed. And among the things we rely on killer T-cells to kill are cancers and cancer precursors

  17. Paul Brookes says:

    Tell you what though – NAC is a great hangover preventer/cure. If you’re headed out “on the pop” as they say, some NAC beforehand to elevate liver GSH levels is likely a good thing (N=1, YMMV).

    1. passionlessDrone says:

      This is the real reason NAC is the MVP! Well over a hundred discrete trials with a N=2 performed.

    2. loupgarous says:

      I’d imagine (from casual experience passing patients getting the “MucoMyst” dosage form of NAC in hospitals) that’ NAC taken before a pubcrawl also makes “social distancing” much easier. I’ve smelled worse things in patient rooms, but not many.

  18. AIC says:

    I thought antioxidants were good not just for cancer but because they make your body “alkaline” and help “flush out” your toxins and lose weight.

    1. I’m not sure if you’re kidding or not, but making your body “more alkaline” will kill you. You’re perfectly situated at the pH you’re in with very little buffer room before acidosis or alkalosis.

  19. Otto says:

    High dosages of thiols (such as NAC) chelate necessary minerals from the body, such as zinc/copper/manganese. Low levels of such minerals may contribute to cancer. So it’s not the high dosages of NAC which are the problem, but the secondary mineral deficiency.

  20. Dylan Richards says:

    Wait a minute…so are there benefits to things we’re told are bad for us? (e.g. benefits of BPA, benefits of consuming pesticides, benefits of process food/nitrates in food?)

    1. Vader says:

      This idea was explored long ago by the literary intellectual side of C.P. Snow’s Two Cultures.

    2. loupgarous says:

      “Radiation hormesis” has long been presented as a viable alternative to the “no threshhold for radiotoxicity” hypothesis. The caveat, of course, usually being that it’s an external dosage of radiation, like the residents of that apartment in Taiwan where some of the steel reinforcement elements had been contaminated by enough Co60 to register on radiation meters.

      I’m unaware of any population studies showing lowered or extended life span for residents of the Colorado high plains, who get higher doses of external radiation from cosmic rays (having one mile less of protective atmosphere above their heads) as well as actinides in their soil (uranium is more abundant in the soil statewide, and much more abundant in seams of the relevant ores in the Rockies foothills).

      1. Barry says:

        A statistically underpowered study was published in airline pilots (who spend time quite a lot higher than Denver)

        1. Vicky says:

          Clothes and windshields protected them? Odd. My quirky brain thought the windshield would have a magnifying glass effect, increasing the risk of cancer. Also, I’d like to see a study of frequent flyer cancer, since air flight attendants also showed a higher risk of cancers.

  21. JIA says:

    NAC has been studied seriously in idiopathic pulmonary fibrosis (IPF) for many years. A randomized controlled trial suggested a detriment: link in my handle.

    1. loupgarous says:

      Thanks for the link!

  22. Nile says:

    Interesting: you’ve raised the point that some cells actually need to senesce and die – something we al knew, but rarely get to see laid out so clearly in a review of the relevant research.

    So this is a very useful illustration for teaching the challenges facing the search for effective life-prolonging therapies; and these limitations, of antioxidants, will probably apply to other approaches too.

  23. Well then… maybe the focus should be on designing therapies that targets neoplastic cells… maybe a glucose based compound with something other added that would be capable of resonating and expressing a significant thermal expression enough to induce protein denatureation to the point of causing irreversible cytoplasmic damage to said neoplasms.
    It can be designed to be toxic so as to satisfy the oncologist society in order to get their approval for use.

  24. Is not NAC considered MORE than just an anti-oxidant? It is a precursor that increases endogenous production of glutathione. Glutathione is the master endogenous detox pathway in the body.

  25. Skincarecdog says:

    A mouse weighs around 20 grams And a lab mouse consumes 15 ml water pr 100 grams body weight pr day so around 3 ml.

    mol = 0.04 M*0.003 L = 0.00012 mol
    0.00012 mol * 163 g/mol = 0.0195 gram or 19.5 mg NAC daily = 1 mg pr gram bodyweight.

    That’s equivalent to a 75 kg man consuming 75 g NAC daily!

    Also, in the mouse study they only had groups of 15 mice, It seems a bit suspect that this got them a P value under 0.05 (using the X2 test), could someone run the numbers?

    It is possible that NAC could be protective from lung cancer at a lower dose, who knows, one take home here is the potential value of cycling supplements.

    1. Peter says:

      Well said. The rats were given extremely high doses. Why did not the writer of this article figured that out? Tests in rats are always misleading because they use astronomical doses of the drugs in them to test for toxicity.

      This study shows how high dose NAC is dangerous.

      No one would take what that rats took in the study, they would die.

    2. Jon Dough says:

      A mouse has about 12.3 times faster metabolism. So 75/12.3 ≈ 6.1 grams

  26. Roy says:

    I have an intellectually open mind. So, I have a general question concerning the potential pitfalls of NAC supplementation: Putting aside everyone that voluntarily takes NAC supplements, isn’t NAC also widely used in hospitals? (

    If it is, then this whole article about the possible pitfalls of NAC is even more disturbing than this article conveys.

  27. Peter says:

    All readers of this blog, the studies posted in this article are missleading and in fact can be dangerous information for people. It is claimed that NAC can initiate the growth of cancer cells based on rat studies and rats that received astronomical doses of NAC toxic to humans.

    There are several studies wish show NAC stops cancer growth, exactly the opposite of what this article claims. I hope the writer reads this comment and updates the article mentioning the result in humans and not in… rats.

    Please all, check the real data done in humans, here are only some studies:

    And there are many more.

    Please Mr. Derek, update your article with this studies.

  28. Anon says:

    The author has worked for “several major pharmaceutical companies”,… Hmm,…

    1. Vicky says:

      Allow me to guess…chemotherapy drugs?

  29. Donkey Dikc says:

    Thanks to the author for stating early on in the article that researchers used 40x the max doses that some folks supplement with ( 2 grams daily ) for general neurological conditions etc.

  30. loupgarous says:

    Revisiting this article, is NAC being tried as a last-ditch preventative for pulmonary fibrosis in late-stage Covid-19? It seems like it might help (but I’m going to withhold the shocked moral indignation if overworked physicians haven’t given it a good try).

    1. Bruce Scott says:

      Yes, clinical trials are being conducted at a dosage of 6g of NAC. The results will be interesting. The chemistry of NAC on the super oxides and its effect on reducing the sulphuric bonds in the Von Willebrands factor seems to work on paper at least.

    2. Debbi says:

      Yes I too read that they are using NAC to treat patients with Covid
      They didn’t indicate in article the milligram but they did indicate it is given by IV to those very ill

  31. Desire Steel says:

    Loupgarous! I am not surprised to hear this. I am a firm believer or Nac being an all time healer. When I heard my older relatives got covid and were starting to really go down hill I rushed down to Georgia to the senior citizens home they are and gave them 2,400 mg of NAC. It’s been 10 weeks since then are they are now negative for covi. Unfortunately since I am not a doctor and I was attempting a last resort effort I didn’t not tell their clinic which I wish I had. Over 50% of the other Seniors that were in the same condition as my great aunt and uncle have since passed. They asked was it anything in particular I did that’s when I explained. They put the other senior residents on Nac and they have all recovered.

    When I read this article I wanted to shoot the messenger. Misleading information like this kills people, but of course anyone who has worked for the pharmaceutical industry would bad mouth natural healing powers. The USA is sick. It’s all about money. You should be ashamed of yourself for writing this and even worse for posting it! Doctors don’t want to heal and cure people anymore, what money would the make them if their customers are all healthy

    1. Anoulie says:

      Desire Steele could you please elaborate on your dosage that you used on your dear aunt and uncle. I am so very happy to hear that they have recovered! They were very lucky to have you as their advocate! If you could let me know how much they took daily and for how long I would so greatly appreciate it! Thank you

    2. Cam says:


      Can you share more on how often (daily/3x weekly, etc.) you provided the 2400 mg NAC to your relative(s) and the entire duration they took the supplement?

      And – do you take this daily for maintenance, and anyone else can chime-in, too please – and from a preventative standpoint – is there a recommended daily mg?

      I got interested in NAC as I saw John McAfee (computer virus guru) on Twitter boast about taking 3,000 mg per day, along with Selenium and Milk Thistle to combat his daily habit of 3 qts of whiskey and 3 packs of UNfiltered cigs – every day.

      Thanks in advance.

  32. Paul Quinn says:

    In researching COVID 19, the most impressive piece of data supporting NAC supplementation as a preventative measure is an earlier study demonstrating its impact on seasonal flu. While NAC and control groups had similar incidence of flu infection, the NAC arm had a shorter, milder course and was more frequently asymptomatic.

    NAC has also been shown to have anti-coagulant properties that have been useful in treating COVID-related coagulopathy. I could potentially seeing it being used as an alternative to ASA for cardiovascular dz prophylaxis.

    1. Rob says:

      NAC seems like a no brainer to me. I have been banging on about the potential of NAC on every platform since I first knew about Covid19 caused by SARS-Cov-2. I am not a Doctor although I was married to one, my mother was a pharmacist. I am not a microbiologist either. I am an industrial chemist and I have an intuitive feeling, a knack about molecules and compounds. NAC has all the correct properties, is accepted by the body, small quantities have been consumed in garlic since ancient times. It increases glutathione. It is relatively cheap, readily available, and not patentable.

  33. nattynotsyn says:

    Synthetics BAD
    Natural GOOD

  34. Zachary Smith says:

    I think one of the most important factors missed here is the chrono-pharmacological aspect of drug administration. The most tightly controlled and preserved aspect of patterns of cellular metabolism are circadian rhythms centered around red-ox balance (which obviously shares strong correlation with anabolism-catabolism cycles). The issue may be that these doses of NAC are given during the day rather than in the evening. All doses of NAC should be taken in the evening at DLMO (dim-light melatonin onset) or later; any other usage pattern than this is likely to be more destructive than useful except in certain populations where NAC is aimed at more than just, say, fighting metabolic syndrome—schizophrenia, autism, etc.

    1. Tam Tam says:

      I was reading a similar article about the massive dosages given to the rodent test subjects. I am wondering if there is maybe a connect between the supplements NAC and PQQ when taken together for Covid-19. Do you believe they may complement one another as I perhaps do?

    2. Chrus says:

      Do you have a link for this?

  35. Nora says:

    NAC cleaves von Willebrand factor and reduces thrombosis. This would certainly benefit anyone fighting Covid; provided it’s true.

  36. Jules says:

    I think I’ve only read one person talking about the fact that this is because the NAC is not found in nature…and cystine is never found alone. These “supplements” are franken-antioxidants. I’m sure if the mice were given some whole food blueberry water (I realize these are different compounds), there would be zero negative side effects. SYNERGY, PEOPLE!

    1. Jon Dough says:

      N-acetylcysteine is found in foods like garlic etc

  37. George M. Carter says:

    The comment above by skincaredog that the mice were given physiologically absurd doses of NAC needs to be taken into consideration. That said, there’s a really great way to offset the hydroxyl radical production: vitamin C. (I wonder too–what proportion of humans are JunD-/-?)

    Were I to have SARS-CoV-2 infection that put me in the hospital, I’d want IV vitamin C with NAC, vitamin D3, zinc, potassium (lots of hypokalemia) and B vitamins. Biology isn’t simple, clearly–and balancing it with micronutrients makes a great deal of sense. Indeed, a lot of covid-19 disease is more to do with the inflammation, coagulation problems and cytokine storm. These agents can help MODULATE the cytokine storm (rather than say wiping out just one like IL-6 or TNF).

    The failure to undertake pertinent clinical studies is an indictment of a system terrible corrupted by pharmaceutical company profiteering, Indeed, we see this with the push to study a basically nearly useless drug, remdesivir. (I’m all for antivirals but it appears they must be given early; so an IV drug for a non-hospitalized patient is absurd; plus, as with most viral infections, it will probably take a couple of antivirals).

    Anyway–here’s another mouse study for consideration.;2-3

    1. Golfsailor says:

      Spot on. I will do the exactly same adding Melatonin !

  38. Ivan says:

    Well, guess what… Too much of EVERYTHING can make you ill…
    You cannot live without water yet you can die from having too much of it…

  39. Jake says:

    As is so often the case, many comments are smarter than the article.

  40. Paul says:

    This thread cracks me the f*ck up. I have moderate COPD and am 3 days into NAC 600 mg bid and the improvement is notable, non placebo, significant respiratory mucous reduction. Carry on with the mice 🙂

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