Doctor's Note

Pregnancy is a very vulnerable time and requires an even higher level of dietary vigilance:

Some supplements are risky for everyone though. See my last video Safety of Noni and Mangosteen Juice.

I've previously addressed green powders in:

If one wants something to sprinkle on their popcorn I'd recommend chlorella instead (Is Chlorella Good for You?).

For more context, check out my associated blog post: Toxin Contamination of Spirulina Supplements.

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  • elsie blanche

    Dr. G, you know anyone at ‘Whole Foods” in upper management (the founder of whole foods is a fellow vegan) whom you can get to watch this video? They sell spirulina in all their stores, and they also formulate some of their store-brand multivitamins with it. No judgement here, I honestly think they don’t know any better.

    • They also sell meat, fish, dairy, and junk food. While your idea is a noble one, I doubt they’d pull the spirulina off the shelves unless forced to do so my some regulatory board. They are a market, albeit a “whole foods” specialty market and they are in the business of making money. I assume like most businesses they will sell what continues to sell. In other words, buyer beware, or more like buyer be educated.

      Maybe if you and other consumers wrote them a letter to see if they could guarantee the safety of or reformulate their spirulina supplement that might have a bigger impact. Maybe?

      • elsie blanche

        Good suggestion in the last paragraph.

    • WholePlantFood

      There are thousands of studies showing that most added supplements to ones diet create more problems than benefits. But Whole Body (the part of WFM that sells supplements) makes a very large profit for WFM and as WholeFoodChomper states below they sell lots of other toxic foods as well, so I do not think they will stop selling the stuff if people keep buying it. Let your Dollar be your vote! If no one buys the stuff they won’t sell it–it’s that simple. Problem is education (again as WFC stated).

      • OzSydDr

        99% of those studies also use vitamins that are Synthetic vitamins, not those sourced from whole food. There has just been studies released showing the complete opposite. The biggest one to date in fact, a 20 year + study following thousands of people showing they had less cardiovascular and cancer indications than those who did not take any multivitamin.

    • Brian

      Yes, I agree with the comment below. ‘Spirulina’ is not a priority when you want to start discussing foods/supplements that need to be removed from shelves. Also, this research is presented in a biased way, you should start reading literature for yourself.

      • guest

        Have you seen solid evidence that the B12 analogues/inactive B12 in spirulina does not in anyway compromise the utilization of true active B12 in humans?
        Vital information for the consumer to know the truth of.

  • Aaron

    Thank you for sharing this. I’ve never experienced insomnia until I tried spiralina about two weeks ago. I had absolutely no idea it would cause such a disruption.

  • Plantstrongdoc M.D.

    Unfortunately no surprise that supplements are contaminated – why not – think of the degree of contamination of the regular food – beef with growth hormone, chicken with feces, fish with mercury and prescription drugs, milk with pus and flame retardants and nothing is done. Money talks.

  • Algae Expert

    I worked for years in the edible algae business and make no profit from Spirulina. More detailed fact checking is in order here. Microcystin contamination can possibly come from blue green algae strains of AFA (Aphanizomenon flos-aquae) which are harvested in the wild
    from Klamath Lake in Oregon. It can also come from other species of AFA. Please see link:

    Historically, microcystin contamination has never been found in either Chlorella or Spirulina any more than malaria has been found in Vitamin C. It is that unlikely. However, microcystin toxins are recorded to
    be commonly found in AFA blue green algae. The FDA considers Chlorella and Spirulina to be GRAS (Generally Recognized As Safe). Factually speaking, AFA blue green algae has never received GRAS designation from the FDA due solely to the occasional
    presence of microcystin which naturally occurs with it. If AFA was mixed with Spirulina, the presence of some microcystin contamination is indeed possible. Otherwise, the presence of microcystin in Spirulina is nil.

    • Shane

      Good on you Algae Expert for some balanced comments to offset the scare mongering on Spirulina.

      Personally I find Spirulina beneficial.

      There are other studies around that show Spirulina to be beneficial.

      eg vegan source of Vit K2
      beneficial for cancer treatment


      • Algae Expert

        · The neurotoxicity BMAA scare had no science
        behind it and was disproven years ago. The notion that Spirulina, unlike AFA, contains hepatotoxins like Microcystin has no
        scientific basis.

        • Maria Hazlewood

          Please help. I was taking raw preserve which contains AFA and Spirulina. Am I in danger? I’m so worried I’m having panic attacks. Please help. Can bmaa be cleansed from the brain / body?

      • Thea

        Shane, as you saw in this video, Dr. Greger is not saying anything about the health or lack there-of of spirulina itself. What I understand the video to be saying is that there is ample evidence that contamination is so rampant in spirulina products that one faces severe risk in consuming them. The health benefits of the spirulina itself are irrelevant if the product contains something overwhelmingly harmful. He’s not saying that *every* incidence of sold spirulina contains harmful contaminants. Just that [too] (in my not-humble opinion) many do. It’s a significant risk.

        I’m all for people taking risks if they want to. Truly I am. What is important is that we all be informed of what the risks are. Then you can decide if that risk is worth it or not. That’s why this video is so valuable.

        A thought for you: I’m willing to bet that whatever benefits you get from spirulina, you could get more safely from other whole plant sources. If so, why not do so?

        • nc54

          exactly, you can get all the vit K and cancer protection you would be getting from spirulina from just consuming some extra kale in its place. .

        • Shane

          Sorry, I agree with Algae Expert on this.
          My opinion from other sources – Scientific Testing on Spirulina has found it to be safe from cyanotoxins like microcystins and BMAA.
          However there are doubts on the safety of AFA blue green algae.

          I use Hawaiian Spirulina , nothing from China.

          I don’t have links to anyone that sells Spirulina.

          There is anecdotal evidence that raw green salads can cause gastro problems and parasite infestation.
          I also eat a significant amount of raw leafy greens daily.

        • Darryl

          The blue pigment C-phycocyanin, about 0.5% of the dry weight of Spirulina (and present in other blue green algae), is of considerable interest, as it can function as a NADPH oxidase inhibitor, overactivation of which is implicated in oxidative stress and diseases with inflammatory causes. A quick scholar search.

          There is a U.S. source 30% phycocyanin extract sold to supplement manufacturers, but its rather expensive.

          • Thea

            Darryl: Interesting. That adds another level to consider. Thanks.

    • Tuni

      Thank you so much for all your factual information. I was and still am worried sick about consuming AMAZING GRASS “raw reserve” . I am 7 months Pregnant and would add 1 tsp daily in my protein shake. I left a message with Amazing Grass and they stated they would look into this topic. I’ve never heard back:(. Do you have any advice or information about the spirilina in this product? Any piece if mind would be SO APPRECIATED. THANK YOU for any information.

  • saeffe

    dear dr. greger, do you know anything about the “lithotamnium calcareum” algae, that is added to my soy-rice-milk because of the calcium? I didn’t find anything about it in the internet. regards from germany

  • Thea

    I live in a part of America that experiences “blooms” of blue-green algae that kill dogs every year. I take such warnings to heart. Unless there was some independent agency who could somehow guarantee that a particular spirulina product was contaminant-free, I wouldn’t want to eat it. It doesn’t seem to me that the benefits outweigh the risks.

  • Kelly

    Do you know if Hawaiian Spirulina Pacifica grown in ponds on the west side of Hawaii Island, in water pumped from deep in the ocean, is any less likely to contain dangerous contaminants?

    • If I’m remembering correctly, aren’t those ponds like right near the airport? I’m just thinking jet fuel contamination, but maybe I’m getting my geography wrong. Anyone want to look it up?

      • Kelly

        Oh my gosh; you’re right! Yikes! Thanks.

  • kathi richards

    Though it the seizures could be caused by the mother’s spirulina use nothing is said about the infant getting any vaccines in those first 24 hours. Most hospitals vaccinate infants for Hep-B shortly after delivery. Only the mother telling them not to stops it. This vac has caused lots of problems for the infants including death.

    • Esther Summerson

      It’s incredible how much I learn, not only by watching the videos and articles by Dr. Greger, but from people’s comments too. This is awesome! Thanks everybody!

  • colonyofcells delacruz

    Not planning to buy any more spirulina. I did finish my last bottle of spirulina that I bought from whole foods and I did not experience any ill effects. The number of people harmed by spirulina is probably a small number so we don’t really hear about it in the newspapers and nobody is stopping the selling of spirulina. The newspapers did cover the Costco frozen fruits with hepatitis A and the same company continues to sell frozen fruits in Costco. I actually ate the Costco frozen antioxidant mix with pomegranate seeds every week for 4 months and did not get hepatitis A.

  • Jan Fitzpatrick

    Dear Dr. Greger;

    This is the response that I got when I expressed my concern to the manufacturer about the quality of the Spirulina in the products that I use.

    Also, there are algae companies that use third party testing. They test the daily harvest on the lake and send samples of the batches to 3 independent labs.

    Kindest Regards, Jan

    Dear Jan,

    Thank you for your email. The powder is tested for microcystin and is not allowed to be more than 0.5ppm, with results of non-detected.

    The spirulina we use is the only Organic Spirulina to be certified by the USP under US Pharmacopeia-Ingredient Verification Program.

    About USP Program:
    Products and ingredients that meet all USP verification requirements – including a GMP audit, product and ingredient testing, and manufacturing documentation review – are then awarded the distinctive USP Verified Marks.

    Manufacturers of dietary ingredients that pass USP Verification can display the USP Verified Ingredient Mark on containers of verified products, as well as on an accompanying Certificate of Analysis. When the manufacturers of dietary supplement finished products see this distinctive mark on the containers of ingredients they buy, they can feel confident that Products and ingredients that meet all:

    • The ingredients are consistent in quality from batch to batch.
    • The ingredients meet label or certificate of analysis claims for identity, strength, purity, and quality.
    • The ingredients are prepared in accordance with accepted manufacturing practices.
    • The ingredients meet requirements for acceptable limits of contamination.

    If we can assist you further, please let us know.
    Kind regards,

    Jeanne Morris
    Sales Operations
    New Earth
    Life Starts Here
    Living Begins Now

  • Tuni

    I’m a little anxious considering I’m seven months pregnant and have been consuming AMAZING GRASS (raw reserve) for about two months. I use a tsp a day in my protein shake. After reading and watching Dr. Gregor video I’m so scared that our unborn blessing will have any issues from my consumption. Any help or extra info on this product would be GREATLY APPRECIATED.
    Thank you,

  • ifyoucareenough

    Hi Dr. Greger — Does brand matter? I got some samples of Vitamin Mineral Green by Health Force Naturals (given at the Seed: A Vegan Experience in NYC a few months ago) . I believe the founder is Jameth Sheridan, who is along with yourself one of the interviewees on Veganpalooza. Health Force Naturals line is supposed to be top of the line.

    • Eating a whole food plant based diet with a variety of vegetables, fruits, starches and beans generally avoids the need for any supplementation except Vitamin B12. If you do take supplements as Dr. Greger points out their are many hidden issues. Most companies do not do third party testing. Best to use the precautionary principle and avoid supplements. Of course with individual variability there are always exceptions.

      • ifyoucareenough

        Thank you. And I was reminded by a friend about green smoothies using kale, spinach, etc. Only thing I hate to shop but I guess I have to bite the bullet.

  • Dean

    I am truly enjoying and being enlightened with the information and opinions/concerns presented here from everyone. As mentioned above New Earth has addressed the many concerns voiced here. Please click to find out more.

  • Joe

    What about chlorella? I remember you mentioning that it is safer, but would it suffer the same problems if grown outdoors?
    Thanks, joe

  • ama

    Is there a difference in certified organic spirulina?

  • CSH

    Hi Dr Greger, What you have to say makes total sense, but what about the company NUTREX HAWAII that produces Pure Hawaiian Spirulina Pacificia. Is your video/article based off of ALL producers of Spirulina? Have you included this NUTREX company in your study as well? Thank you for your interest in this subject. I look forward to hearing your reply.

  • spartan carol

    Comparing this with my Lifepak and with all the recent updates about Spirulina I have read, I would still not dare to replace my Lifepak daily dose. :) read and learn more about it. it’s perfect for everyone!Been taking it for almost 4 years, never’ve been so satisfied every year when I see my regular blood chem and urinalysis results!

  • HB

    This is in supermarkets and even in the local coop:

    Simply Nutritious brand’s “Mega Green” which is lower in grams of sugar than most any other fruit juices:


    There are videos on NF saying that spirulina however is harmful as a “supplement” but
    about about as one ingredient in a juice…since this juice by R.W.
    Kudsen is sold all over the place (and since I like the taste and the
    low sugar) I’m wondering if in the amounts present (amounts of
    spirulina) in that juice if it’s harmful or harmless?

  • Jessica Cook Rodrigues

    Dr. Gregor. Is all spirilina contaminated with blue green algae? Should we avoid any product that contains spirilina? Have you heard of shakeology? Spririlina is in all of their flavors. Do you know of any testing done on shakeology?

  • ANON

    vaccine damage ? creepy,as soon as it comes out,they’ve got a vaccine waiting for the little one !

  • Redirectionalism Redirectional

    That was very enlightening and helpful Doctor, thank you.

  • Ricardo


  • Ricardo

    I was under the impression that the egg industry cannot use the word “safe” in their products. I …

  • Sidney

    So if I buy spirulina that is grown indoors in man-made ponds, is it safe from contamination?

    • Jennifer Smith

      Contamination is the presence of an unwanted constituent, contaminant or impurity in a material, physical body, natural environment, workplace, etc. Under this definition everything can be considered contaminated. However, spirulina grown inside controlled man made “greenhouses”, have the ability to have much more quality control over large commercial open made made ponds. The question is not the specific contamination, the question is will this impurity harm you? No to worry, if you have a normal functioning strong immune system it will take care of it and cause no harm.

  • Laura Stanasila

    I have seen a low-carb, high-fat diet touted as a remedy for infant seizures, what is your take on that? Is there a plant-based alternative that can be helpful with infant epilepsy?

    • Thea

      Laura: Here’s my take: The diet you describe that helps children with epilepsy is called a ketogenic diet. That diet is well known to be extremely unhealthy both short and long term for most humans. But it seems to help people with epilepsy. To me, this is an example of how people with diseases and special conditions may need something different than what is best for the vast majority of humans. In this case, the difference is dramatic. In other cases, the differences are less dramatic. For example, someone who is allergic to peanuts can not eat peanuts. But peanuts are healthy for the vast majority of humans. Similarly, there is a rare congenital defect where someone’s body can’t make on of the non-essential amino acids that everyone else’s bodies can make. In that case, the person needs to eat meat or take a pill for that amino acid. But for the majority of humans, meat is an unqualified unhealthy food. My bottom line is: I think there are lots of examples like this, and it is just sad that we don’t have something better for those kids.
      Having said that, Dr. Greger has touched on epilepsy in some of his videos. Maybe these will answer your question better than I:
      What do you think?

  • TK

    Is this info about spirulina still true, your recommendation to avoid it due to uncertainties of toxins?

  • AJB

    I wonder if

    • AJB

      I’m wondering if Earthwise spirulina is good as this company claims it is the safest spirulina on the market and it’s grown in the California desert. They have some certifications but I’m not sure if it’s the kind that Dr. Greger mentioned he’d want to see.

  • Jennifer Smith

    I feel that there are risks from consuming anything…most common is water. Just do a search on contaminated water, you’ll find a whole list of current stories. Are you going to stop drinking water?

    Everything we consume has a story somewhere of some contamination at some time. The fact is that whole plant foods in their natural normal state as nature intended are by themselves very safe and healthy. If we run sewage onto a spinach farm from animal agriculture, there is a good chance the spinach is contaminated with E coli. That doesn’t mean spinach is a dangerous food.

    It is not the food itself but the way it is grown and harvested. Spirulina by itself is a whole food, not an isolated supplement. Algae grown in toxic water can be contaminated, but the algae itself is very nutritious. We need to grow and consume spirulina locally like we grow sprouts and not destroy it before we consume it.

    Most spirulina is grown in china in big open ponds which are exposed to all kinds of environmental issues. This is one reason why they incinerate their products at over 202 degrees C. (395.6 F) to kill any possible microbes. This also kills the spirulina. So why buy dead powder spirulina from a very toxic far away country? Would you prefer to buy spray dried dead celery from the produce isle in your local grocery store? The nutrition is dramatically reduced by heat processing of any food, especially spirulina which is very fragile.

    I think the nutrition value of food is much more of a concern than any possible minimal contamination risk. When our immune system is kept strong, as nature intended, we can easily fight off disease causing things that we come in contact with.

    • Imagine this… our clothes (cotton) are contaminated with more pesticides than in food and you can’t wash it off. Safer and healthier to just go naked… And you’ll get your vitamin d in the process.