Doctor's Note

For some background on creatine, see yesterday's video. I have 51 other videos on brain health, including Constructing a Cognitive Portfolio,Improving Mood Through Diet, and Reversing Cognitive Decline, as well as hundreds of other videos on more than a thousand subjects. Note that the contaminant study is open access, so you can download it by clicking on the link above in the Sources Cited section.

For more context, check out my associated blog post: Probiotics and Diarrhea

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  • Michael Greger M.D.

    For some background on creatine, see yesterday’s video. I have 51 other videos on brain health, including Constructing a Cognitive Portfolio, Improving Mood Through Diet, and Reversing Cognitive Decline, as well as hundreds of other videos on more than a thousand subjects. Note that the contaminant study is open access, so you can download it by clicking on the link above in the Sources Cited section.

  • Tan Truong

    Dr. Greger, please let us know when it’s safe to supplement creatine. I could use some cognitive boost.

    • Michael Greger M.D.

       Did you watch through to the end? It’s probably best not to take supplementary creatine.

      • Joe Smith

        You mentioned 50% of the Creatine supplements are contaminated.. Which of the 50% were not contaminated?  Do they spell out any brand names or anything?  I have exams coming up!

        • Darrylsroy

          The referenced article found 44% of the Italian market creatine monohydrate samples had creatinine (the body’s own creatine metabolic product, so harmless), and 15% with 4.5-8 mg/kg dihydro-1,3,5-triazine (4.5 mg/kg being EFSA’s limit) and > 50 mg/kg dicyandiamide (resulting from inadequate water during manufacturing recrystallization).  So it looks like 15% of the samples were contaminated with fairly low amounts of toxic manufacturing byproducts.

          I’m a bit more concerned about elevated intramuscular IGF-1 from creatine consumption (Int J Sport Nutr Exerc Metab. 2008 Aug;18(4):389-98).  Probably desirable from a bodybuilder’s standpoint, but problematic given all the smoking guns linking elevated IGF-1 and cancer proliferation.

          • albert

            According to that article, found here:

            IGF-1 only increased when creatine was combined with heavy resistance training. This increase of IGF-1 may have been an indirect result of the creatine since it allowed the subjects to exercise harder, producing better results and greater hypertrophy. In such a case, the body uses its IGF-1 appropriately and there is no increase in risk of cancer. The body is wise enough not to produce an excess. Excess IGF-1 is a result of excess protein, “complete protein,” and zinc, all found typically in animal foods. Incidentally, the vegetarians experienced the greatest muscle gains. A clean diet definitely helps.

  • Mike

    This is some of the worst science I have come across.

    • Tetranomad

      This is some of the worst blog commenting I have come across.

      • Mike

        How much meat is eaten. What sources of meat are eaten. How much creatine is in those source. Why is the study only 4 days long? That is not enough time for the body to regain its equilibrium. Because of this short period of time, of course you will see positive results. The body will have a positive balance of creatine. Meat eaters already have a creatine balance. Where and why does intake of a water soluble supplement such as creatine decrease cognitive function? I say water soluble because if additional creatine is ingested and the body does not use it, it is pissed out in the urine. I can continue on and on about how terrible this study is. I’m not against a vegetarian lifestyle. I actually promote many aspects of it. This particular study though is absolutely ridiculous. Extend the study out to 4 or more weeks minimal so that each test group has the ability to regain their equilibrium and you will likely see no significant difference.

  • Paul

    I take a brand of creatine monohydrate marked 100% pure powder. If 100% means what I think it does, there are no contaminants in it at all. Creatine supplementation is said to lower homocysteine as well as giving an energy boost for anerobic activities and now, helping memory. On balance, I can find more reasons to continue taking creatine than to shrink away from it.

    • Rschommer

      From the bigger picture, it is key to note the initial graph in comparison between the vegetarians and omnivores concerning cognitive memory. They are almost exactly similar in value…….even with the tremendous amount of average meat(muscle) consumed by the average omnivore.

      As a low fat vegan, I am very comfortable with the knowledge that my own body can manufacture creatine……….in multiple locations and capacities, as needed—–without supplementation from actual meat or toxic pills. Too much of a “good thing”, especially from unnatural sources usually or can lead to trouble. Let’s all not forget, Vitamin A, Vitamin E, Selenium and several other pill supplements as opposed to the real mccoy, from natural food sources.

      Really believe the bigger picture of cognitive function is more strongly related to atherosclerotic plaque formation in the large(carotid) and numerous small blood vessels leading into and within the brain. Hard to provide the 20 percent needed nutrients to this super computer when the inflow roads are blocked.

      However, we presently do have great medical documentation concerning cleaning out these plaque deposits and continuing to maintain our blood vessels is the research from Dean Ornish and Caldwell Esselstyn. 

      The answer is a low fat vegan diet with moderate exercise, plain and simple.
      What is good for the heart, will be good for the brain (memory). My opinion anyway.

      • griffd

        Be careful with a “low fat” diet – fat is an extremely important part of the diet, and it also helps facilitate absorption of nutrients from your fruits and veggies. I think low (or no) animal consumption is the best way to go, but we should get nearly all our fat from whole food plant sources (like nuts, seeds, avocados, etc). I think we got to get rid of the old school terminology here – low carb, low fat, high protein, it’s all so misleading. It focuses on macro-nutrients and doesn’t take into affect the micronutrients, fiber, etc etc. Whole food (mostly) plant based high-nutrient diet? It’s a mouthful :) Dr Fuhrman calls it “nutritarian” which is simple, but not completely descriptive either. 

        • Toxins

          Actually, all the essential fat we need is found in greens, fruits and grains. We have no dietary need for seeds or nuts, nor is a healthy diet dependent upon these foods. Monounsaturated fats are produced in the liver while we must acquire omega 6 and 3 through food. Men need only 1.1 grams of omega 3, women need 1.6 grams of omega 3. If we eat low fat whole plant foods our dietary fat needs are met.

          Here is Jeff Novick’s chart on omega 3 supply in the diet, you will find that the best nut choices are flax and walnuts, as well as chia which is not listed.

          In addition, if one were to eat a lot of peanuts or almonds throughout the day, we would throw our omega 6: omega3 ratio off. We should strive to keep the ratio at 4:1 or under. Peanuts have a ratio of 4400: 1 Almonds have a ratio of 1800: 1Eating these foods on a constant basis will not allow the omega 3 to synthesize efficiently, omega 6 is already significantly more abundant then omega 3.

  • griffd

    If you took creatine supplements regularly, wouldn’t your body stop producing it just like if you were regularly eating meat? And if so, I wonder how long it would take to adjust – maybe you could save the creative supplements for those special days when you need the athletic performance boost.  ???

    • Shane Jackson

      The instructions for use on almost all powdered drink creatine supplements call for a loading period where the subject is supposed to take double the daily dose for 5 days before backing off to the normal maintenance dose. So it appears at least according to the supplement dealers that not having a consistent amount present in the body doesn’t allow for the full benefit. Whether this is actually the scientifically correct method of supplementing with this or just a way for the supplement companies to make their purchased product disappear faster I couldn’t tell you. I will say that when I used to take it my brain/mind seemed to go into a little overdrive where I seemed to be extra alert and able to focus a little more than normal.

  • Terra Preta

    The contaminant study doesn’t appear to be open access; at least for me, I have to register and pay $36 to view it.

  • Terra Preta

    I noticed my creatine claims to test each batch using state of the art HPLC. It lists the levels of organic contaminants and heavy metals.  It claims it is the purest on the market.  It’s called Creapure and it’s by Integrated Supplements:
    I’m assuming it’s valid.  It acknowledges that contaminants are often present in creatine products.

  • Mike Snyder

    Is L-Arginine safe to take for High Blood Pressure?…thanks…Mike

  • Alexandra Lupin Rajzman

    So how do we boost our vegetarian brain performance without creatine supplements?

    • James

      (I know this is three years too late, but for anyone else reading…)
      In my opinion, you’re already running at max capacity, at least naturally.
      Although contamination is in 50% of products, if you need a brain boost for a couple of days (and you’re a vegetarian or vegan) take the supplements 4 days before. Then after the test, stop the supplements due to health concerns. Also, if you continued taking the supplements your body would most likely adjust and lower your own supply of creatine.

  • Anja

    Hello, I am a plant-based athlete/body builder, personal trainer and dancer and my brother (who is also a plant based athlete) sent me a supplement over from Austria called “Tribulus Terrestris”. He adds it to his shakes/smoothies and he swears by it. I just wanted to ask for your input on whether this is a good option for females as well?

    • albert

      Yes, it stimulates the body to produce lutenizing hormone which causes a cascade of other hormones as appropriate for either sex. However, it’s possible that frequent continual usage will result in the body adapting to Tribulus- or any exogenous supplement, resulting in its effect decreasing, perhaps to the null point. For this reason I rotate between one of seven adaptations and one of seven sex stu

  • Derrek

    Is supplementing with creatine safe? What about like brown rice protein, pea protein or any plant based supplement like Sunwarrior?

    • albert

      Recently, I read an article that indicates that it’s safe for the kidneys, which was their main point of concern: I would recommend using a brand such as NOW which is tested in their lab with very sophisticated mass spectrometers to assure that it’s 100% pure. You can call them up and talk to customer service to get info on their quality control- that’s what I did. If pea or rice protein is also pure, there shouldn’t be any problem- but why not eat the whole food pea or brown rice instead? It’s cheaper and has more fiber and micronutrients.

  • Derrek

    I use pea and brown rice for protein and BCAA.

    • Toxins

      Getting enough protein is not really an issue unless you are not eating enough calories to begin with, which is essentially starving oneself, or you are consuming a strict fruitarian diet. Other then that, not getting enough protein is a non issue.

  • Jsr

    Are vegans creatine /deficient/??

  • William Dwyer

    I took creatine for awhile and felt great while I was on it. My
    strength also increased noticeably at the gym. Wow! I was riding high
    on that stuff! What could be better? However, since I have a
    blood-pressure monitor and take my blood pressure frequently just out of
    habit and curiosity, I took it while on creatine, and what did I

    Holy Sepulcher! It had jumped from 110/70 to 150/95.
    At first I thought there must be something wrong with the monitor, but I
    kept getting the same high numbers no matter how often I took it. I
    called Kaiser and talked to the advice nurse, who told me that I should
    stop taking the creatine, because it causes your body to retain water
    and could drive up your blood pressure. I did stop, and after a couple
    of days, my blood pressure returned to normal. By the way, I was only
    taking 2 grams per day. Body builders take 20 grams per day in the
    loading phase, and for maintenance, they take 5 grams per day.

  • trent

    Results of this study overstated (misrepresented).
    Graphs used in Dr. G’s chart misleading.

    I read actual study:

    1. Placebo arm for veggie & meat eater before & after.
    2. Creatine arm for veggie & meat eater before & after.

    The baseline “before” levels were different between placebo & treatment arms. (the comparison being made was within group before/after)

    The “before’ in Dr. G’s graph actually the “after” in placebo group.
    The “after” in Dr. G’s graph is the “after” in creatine supplemented group.

    Dr. G jiggered study graphs to give appearance vegetarian performance actually improved following creatine supplementation (it did not).

    The only statistically significant difference [ based on study authors analysis] was word recall better in veggie group after creatine supplementation than meat eater group after supplementation.

    No group [ veggie, meat eater placebo or creatine arm] did better in word recall at the end of study than at baseline!
    Trend downward in all cases.

    Veggie group supplemented with creatine just did LESS WORSE.
    This finding in itself note worthy.
    Maybe due to effects (brain drain) of continual bombardment with memory/recall tests in which one is not actively learning and cannot really learn.

    (Standardized K-12 curricula anyone?).

    Perhaps the barrage of tests should be repeated with black coffee, black tea, green tea, M&Ms and placebo control arms.

  • Mindaugas Raulinaitis

    And what about your video “Heterocyclic Amines in Eggs, Cheese, and Creatine”? I am taking creatine supplements at the moment…

  • Derrek

    Do you recommend creatine supplementation? I have a bad memory?

  • Violet

    Ummm… thanks for nothing? Now I want something that I didn’t previously know existed and that I just found out is likely bad for me! What a mind *uck!


    Creatine Supplementation for Vegetarians (and all older athletes)

    Can a vegetarian diet lead to underperformance in endurance sports? That
    is, even if protein requirements are met (on a vegetarian diet) is
    the athlete still at risk for under performance compared with those
    who eat meat (omnivores)?

    article suggests that may be the case, at least in older athletes,
    and got me started on this search of the medical literature.
    of a meat-containing diet contributed to greater gains in fat-free
    mass and skeletal muscle mass with RT (resistance training) in older
    men than did an LOV (lacto-ovo vegetarian) diet.”

    are several possibilities for this observation – 1) a subtle deficit
    of basic dietary elements such as carbohydrates and protein or 2) a
    nutritional component found in a meat based diet but lacking in a
    vegetarian diet. This paper raises the possibility that it is a lack
    of creatine that is the performance risk factor for vegetarians. We
    know that vegetarians often need to supplement micronutrients such as
    iron, zinc,
    vitamin B12 (cyanocobalamin), vitamin D and calcium (either by using
    supplements or altering their dietary intake). But now we add the
    potential of a creatine deficiency (which cannot be met on a meat
    free diet). “Creatine
    supplementation provides ergogenic responses in both vegetarian and
    non-vegetarian athletes, with limited data supporting greater
    ergogenic effects on lean body mass accretion and work performance
    for vegetarians”

    Creatine is found mostly in meat, fish and other animal products and this does
    impact vegetarians. “… the levels of muscle creatine are known
    to be lower in vegetarians.”


    “A vegetarian diet is correlated with a lower muscle creatine.”

    Not only can creatine levels be low in the muscles of vegetarians, it has
    found to be lower than in omnivores in the brain as well. And it has
    been suggested that a lower level may impair mental as well putting
    vegetarians at small risk. ”…in vegetarians rather than in those
    who consume meat, creatine supplementation resulted in better

    The creatine deficit occurs fairly quickly, in less than a month, when
    switching to a vegetarian diet. “..The
    results demonstrated that consuming a LOV diet for 21 days was an
    effective procedure to decrease muscle creatine concentration (p
    <.01) in individuals who normally consume meat and fish in their

    So the question is whether creatine supplementation makes sense for
    vegetarian athletes? Is it possible to take supplements (assuming
    that the creatinine supplement, probably derived from animal sources,
    is acceptable to vegetarians). Interestingly, vegetarians as a group,
    respond more dramatically and in a relatively short period of time
    to such supplementation. Just 5 days of creatine supplementation
    increase tissue levels. “The results indicate that VEG have a
    lower muscle TCr content and an increased capacity to load Cr into
    muscle following CrS. ”

    The increased responsivness to creatine supplements is confirmed in this
    study. “Vegetarians
    who took Cr had a greater increase in TCr, PCr, lean tissue, and
    total work performance than nonvegetarians who took Cr (P<0.05).
    The change in muscle TCr was significantly correlated with initial
    muscle TCr, and the change in lean tissue mass and exercise
    performance. These findings confirm an ergogenic effect of Cr during
    resistance training and suggest that subjects with initially low
    levels of intramuscular Cr (vegetarians) are more responsive to

    So we know that tissue creatine levels are lower in vegetarians, that
    this may be a reason for a decrease in performance, and supplements
    can fairly quickly reverse this deficit. Are supplements safe?

    Creatine is a relatively safe supplement with few adverse effects reported.
    The most common adverse effect is transient water retention in the
    early stages of supplementation. When combined with other supplements
    or taken at higher than recommended doses for several months, there
    have been cases of liver and renal complications with creatine.”

    What dosages have be used in these studies?

    First, the formulation – “Creatine monohydrate is the most studied; other
    forms such as creatine ethyl ester have not shown added benefits.

    “0.3g·kg·d for 5 to 7 days, followed by maintenance dosing at 0.03
    g·kg·d….However loading doses are not necessary to increase the
    intramuscular stores of creatine

    g/kg of body weight” per day

    There are many articles on the benefits of creatine supplementation in
    power lifters and for other anaerobic activities such as sprints.
    This is the only study I could find that addressed aerobic endurance
    performance… and as in many of these studies, the subjects were a
    younger population. Remember that the initial article specifically
    qualified the statement to “older
    men”, who may be more susceptible to the creatine deficit
    of a vegetarian diet. “Cr supplementation did not result in any
    improvement in upper-body maximal strength and in endurance running

    So let's switch the focus for a minute to the older, non vegetarian
    athlete. Interestingly the younger meat eating athlete does not
    appear to be as sensitive to creatine supplementation as the older
    athlete. Perhaps it is the fact that a minor change in performance is
    hard to demonstrate statistically and only becomes evident when
    accentuated by the age factor.

    Article after article supports the idea that creatine supplementation is
    beneficial for the older athlete looking to improve performance:

    1) “Supplementing
    with creatine, a high-energy compound found in red meat and seafood,
    during resistance training has a beneficial effect on aging muscle.”

    2) “creatine supplementation to be a safe, inexpensive and effective
    nutritional intervention, particularly when consumed in conjunction
    with a resistance training regime, for slowing the rate of muscle
    wasting that is associated with

    3) “These data indicate that creatine supplementation without associated
    training in the elderly could potentially delay atrophy of muscle
    mass, improve endurance and strength, and increase bone strength, and
    thus may be a safe therapeutic strategy to help decrease loss in
    functional performance of everyday tasks. Generally, however,
    creatine supplementation, without associated resistance training,
    seems to enhance muscular strength, power and endurance, increase
    lean body mass (LBM) and improve the functional capacity of the

    4) “Creatine is an inexpensive and safe dietary supplement that has both
    peripheral and central effects. The benefits afforded to older adults
    through creatine ingestion are substantial, can improve quality of
    life, and ultimately may reduce the disease burden associated with
    sarcopenia and cognitive dysfunction.”

    And as a bonus, it may help the aging brain as well. ”…subjects
    consumed either a placebo or 20 g of creatine supplement for 5 days.
    Creatine supplementation did not influence measures of verbal fluency
    and vigilance. However, in vegetarians rather than in those who
    consume meat, creatine supplementation resulted in better memory.

    Again this beneficial effect may be age accentuated as “…creatine
    supplementation does not improve cognitive function in young adults.

    I think we have plenty of evidence that creatine is part of the
    problem. Are there any other factors (in addition to a relative
    creatine deficiency) that might the contribute to a performance
    deficit in the older meat eating athlete? Daily
    protein requirements (RDA), whether from plant or meats, do increase
    as we age and may compound the problem of athletic performance for this group.
    “These results suggest that the RDA for protein may not be adequate to
    completely meet the metabolic and physiological needs of virtually
    all older people.


    recommended dietary allowance of 0.8 g protein x kg(-1) x d(-1) might
    not be sufficient.”

    So what are my conclusions after this investigation?

    1) If you are in that older age group (65 – 70) creatine
    supplementation makes sense – for cognitive as well as muscle
    strength. I plan to give it a try for a month although I'm not sure
    how I will eliminate a placebo effect as I try to decide if it is
    helpful. Based on the data, even if I am doubtful I will probably
    continue it if I don't experience any negatives.

    2) If you are a vegetarian, or an “almost vegetarian”, the age limit
    where a benefit can be demonstrated decreases. What age? There is no
    data. But as it is a safe supplement I'd give it to any performance
    athlete who is a vegetarian.

    3) Will this help endurance performance (as opposed to resistance or
    anaerobic activities) in vegetarians or the older athlete? It may not
    increase your time to exhaustion in aerobic activities, but if it
    leads to an increase in muscle mass, strength and the watts of power
    you can generate should increase as well, which can't help but
    improve your performance up to that point of exhaustion.


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  • 1992Matze

    Most creatine supplements are made in China. What is about the German Creatine (Creapure®)? It is brand quality (99.99%). I would appreciate it very much, if you could say something about it. ;-)