Toxin Contamination of Spirulina Supplements

Infant Seizures Linked to Mother's Spirulina Use

On his first day of life, an infant was hospitalized with seizures. Researchers concluded that his mother’s daily spirulina use starting in the fourth month of pregnancy was likely to blame. I’ve talked previously about the liver and nerve toxins present in many spirulina supplements, but the supplement companies swear up and down that spirulina doesn’t produce those toxins, and they may be right (See my video Infant Seizures Linked to Mother’s Spirulina Use).

But if spirulina doesn’t produce toxins, how is it that toxins are found in spirulina supplements on store shelves? It appears to be contamination of spirulina with toxin-producing blue-green algae.

For example, if we look at the new U.S. Pharmacopeia safety evaluation of spirulina, researchers conclude that “the available evidence does not indicate a serious risk to health or other public health concern when spirulina is properly identified, formulated, and used.” Ah, but that’s the catch. Spirulina is often grown and collected in open lakes and we have no idea what other algae are going to crop up.

The researchers reported a range of adverse reactions of people taking spirulina products, ­­but they attribute these issues to non-spirulina algae toxin contaminants within spirulina supplements. So unless there’s third-party testing of each batch (which no company could presumably afford to do), I continue to encourage people to avoid spirulina (and blue-green algae) products.

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

I’ve previously addressed green powders in:

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

Some supplements may be risky for everyone though. See, for example Safety of Noni and Mangosteen Juice.

-Michael Greger, M.D.

PS: If you haven’t yet, you can subscribe to my videos for free by clicking here and watch my full 2012 – 2015 presentations Uprooting the Leading Causes of Death, More than an Apple a Day, From Table to Able, and Food as Medicine.

Image credit: SurFeRGirl30 / Flickr

  • Thea

    Dr. Greger, I really appreciate you taking on this topic for a blog post. I have spoken to several people who swear by their spirulina usage. I have tried to refer them to the videos, but I doubt anyone clicked the link. They say, “But my brand says that it is pure…” This blog post is a really nice summary that I can now use to e-mail to someone. I think this will be more effective and the recipient of the info can follow the video links if they want more info. Thanks!!!

    • Roseveg

      Lots of vegan protein powders have this stuff in it, as well as some multivitamins.

      • Thea

        Yet one more reason to skip protein powders and multivitamins. :-) Thanks.

        • Mindy

          One serving of NOW pea protein contains 24g of 100% pure non-gmo pea protein. I tried VegLife Peaceful Planet Pea Protein and had a severe allergic reaction to the gm maltodextrin in it. Lips and back of throat swelled up. Scary!

          • Thea

            Mindy: re: swelling.
            Yikes! That is definitely scary.

            I’m glad you got through it OK!

    • Lyndia Storey

      Thea, please do your research…. Dr. Greger doesn’t know the difference between Klamath Blue Green Algae and Spirulina. Spirulina has been on the planet for 3.6 Billion years…. it is (culturally) eaten for thousands of years be African people living near/around Lake Chad & in the Rift Valley of Ethiopia…. there are hundreds of medical and scientific articles published and available on line that speak to it’s nutritional value and health benefits. Having now taken it myself for 30+ years & enjoyed near perfect health I would have to respectfully disagree with the doctor on what he writes and the disservice he does for people seeking good health.

      • Thea

        Lyndia Storey: I’m very glad to hear you haven’t been harmed by contaminated spirulina.
        But note that none of your arguments are logical. How long a substance has been on the planet is irrelevant to whether or not it is harmful to humans. Neither is it relevant to whether or not contaminated products get sold by modern suppliers. How longs humans have consumed a product is equally meaningless. As Tom Goff recently pointed out so aptly to another poster, some human cultures have also long practiced drinking urine and eating other humans. Obviously, just because a human society has copied a practice generation after generation does not make that practice healthy. Neither does one anecdote (yourself or anyone else) of someone being fine taking a product. After all, how many times have you heard of someone who smoked heavily for decades and never gotten cancer? But the science tells us that smoking is definitely a risk factor for cancer. Finally, your point about there being studies showing that spirulina is healthy is not in dispute. Thus, your point there is what is known as a strawman’s argument.
        I have no problem with someone saying that they are happy to take the personal risk of consuming a product (as long as doing so doesn’t affect other people). But I do feel that everyone has the right to be properly informed of the science and potential risks. That’s what I would say this article is about. Informing us of the risks. And I think a responsible approach from anyone (such as yourself) sharing with others about the benefits of spriulina would also including sharing about the risks now that you know about them. Seems the ethical route to me…

  • Ann

    But in your study of chlorella you said that it was unsafe so why would you recommend it instead of spirulena ? It sounds like both are unsafe…

    • guest

      My heart almost stopped beating after taking chlorella. If you have autoimmune issues – and even if you don’t! – I’d be wary of using chlorella. And I used arguably the most reputable brand out there.

  • Ida

    Just wanted to share my experience with chlorella; I have eaten chlorella on and off now for about two years and it has really helped me with my menstrual pain. As soon as I stop taking it the pms returns so I always make sure I have some chlorella in my cupboard now :-)

    • Roseveg

      What brand?

  • Mindy

    I have been taking Hawaiian Spirulina from Nutrex for the past few years and I have every confidence that it is a clean product, free of toxins. I sent them Dr. G’s post and here is their response:

    Hawaiian Spirulina Pacifica® is not collected from natural blooms in open lakes. Hawaiian Spirulina Pacifica is grown under carefully controlled culture conditions that are monitored daily. Each lot of Hawaiian Spirulina Pacifica passes 15 different quality assurance
    tests, including complete microbiological testing, before being released for sale. In addition, Hawaiian Spirulina Pacifica is regularly tested for toxins by independent third party laboratories. In over 30 years of testing no toxins have ever been found present in Hawaiian Spirulina Pacifica. Quite to the contrary, many health benefits have been and continue to be reported as a result of
    consumption of Hawaiian Spirulina Pacifica.

    Cyanotech Corporation produces Hawaiian Spirulina Pacifica® at its facility in Kona, Hawaii, USA under US Food and Drug Administration laws as certified by the Natural Products
    Association. Hawaiian Spirulina Pacifica is certified as Generally Regarded As Safe (GRAS) by US-Food and Drug Administration and may be used in any food, beverage, or supplement.


    • guest

      What percent of the B12 in this product is a false/analogue version of B12, and what percent is real B12? They put “B12” on the label, but spirulina might not contain much absorbable/usable B12 for humans.

      • Mindy

        From Nutrex:

        In regards to Vitamin B-12,
        the nutritional analysis is more complicated than with other nutrients. There are two different kinds of Vitamin B-12: Human-active B-12 that the body can absorb and utilize, as well as analogue B-12 that is not absorbed by the human body. Both human active and analogue B-12 are found in Spirulina, but the relative amount of human active and analogue B-12 is currently in dispute The
        remarkably high quantity of human active plus analogue B-12 found in a 3 gram
        suggested daily serving of Hawaiian Spirulina totals 9 mcg. This figure can be
        broken down as a minimum of 36% human active (or 3.24 mcg per 3 gram serving), and 64% analogue (or 5.76 mcg per 3 gram serving). The analogue B-12 in Spirulina in no way interferes with absorption of human active B-12 and has no other known side effect or contraindication. It is not, however, absorbed by the human body. Thus, the absorbable fraction of Vitamin B-12 in a 3 gram daily serving of Hawaiian Spirulina represents 54% of the Daily Value as recommended by the US FDA.

        • Eileen

          I can’t thank you enough for digging for this information and passing it on. Many thanks!

          • Mindy

            I always try to go directly to the source of origin when I have a question about a product. There is simply too much misinformation on the net.

        • guest

          Did nutrex provide a study and or proof that the analogue B12 in no way interferes with the absorption of human active B12? Maybe the active form is “absorbed”, but can it then actually be utilized by the human body? I think the burden of proof is on nutrex to show this.

          • Mindy

            You can direct your question to Julia Linhart, sales rep

          • guest

            What did Julia provide to you as far as an answer on this question? I think it would serve the viewership here to have knowledge of the question you were previously asked. You posted other stuff from Nutrex, hopefully you can do the same on this front, as this issue I have raised is vital to the integrity of the B12 status of vegans (as well as some non-vegans) who use spirulina.

  • Jack

    I think Dr. G’s raising awareness of the potential problems with Spirulina or BGA sources is good. I am very careful to avoid lake sourced BGA for the points mentioned. Like Mindy, I consume a product with Spirulina Pacifica in it which is manufactured by Nutrex and am confident it doesn’t present the contamination risk of Spirulina sourced from lakes. I don’t believe a general statement that all Spirulina is bad or potentially dangerous because we don’t know the source is the answer. If one is using a reputable manufacturer and they aren’t involved in making or selling open lake sourced Spirulina I feel confident enough it is doesn’t present the same concerns.

  • Rick Stevens

    Spirulina is healthful, and quite safe. Just make sure you purchase it from the better brand names, or grow it yourself. This particular infant just had an allergy to it. Infants show up in the E.R. all the time with reactions to all kinds of foods. This is an example of cherry picking to discredit Spirulina.

    • Shane

      Read the previous threads on Spirulina .

      Dr Greger negative comments on Spirulina are not backed up by any scientific evidence.

  • nancy

    Have you looked into the safety of Nutrex spirulina?

  • Akhil

    How can i trust this guy when he is the director of animal agriculture of united states? Obviously spirulina could replace his animal products.