Drug Levels and Effects:

Summary of Use during Lactation:

Chlorella sp. is a fresh water green algae that contains various nutrients such as protein, fiber, vitamins, minerals and chlorophyll. No data exist on the excretion of any components of Chlorella into breastmilk. Studies in Japan found that supplementation with Chlorella pyrenoidosa (Sun Chlorella A tablets, Sun Chlorella Corp. [Kyoto, Japan]) during pregnancy decreased the amount of dioxins and increased the concentration of immunoglobulin A in breastmilk.[1][2] Chlorella is usually well tolerated, but can cause nausea, diarrhea, abdominal cramping, flatulence, and green stools. Allergic reactions, including asthma and anaphylaxis, have been reported in people taking Chlorella, and in those preparing chlorella tablets. Photosensitivity reactions have also occurred following ingestion of Chlorella. The high vitamin K content of Chlorella may decrease warfarin effectiveness. Maternal Chlorella intake would not be expected to cause adverse effects in most breastfed infants and is probably acceptable during breastfeeding.

Dietary supplements do not require extensive pre-marketing approval from the US Food and Drug Administration. Manufacturers are responsible to ensure the safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products. More detailed informationabout dietary supplementsis available elsewhere on the LactMed Web site.

Drug Levels:

Maternal Levels.

Relevant published information was not found as of the revision date.

Infant Levels.

Relevant published information was not found as of the revision date.

Effects in Breastfed Infants:

Relevant published information was not found as of the revision date.

Possible Effects on Lactation:

Relevant published information was not found as of the revision date.


1. Nakano S, Noguchi T, Takekoshi H et al. Maternal-fetal distribution and transfer of dioxins in pregnant women in Japan, and attempts to reduce maternal transfer with Chlorella (Chlorella pyrenoidosa) supplements. Chemosphere. 2005;61:1244-55. PMID:15985279
2. Nakano S, Takekoshi H, Nakano M. Chlorella (Chlorella pyrenoidosa) supplementation decreases dioxin and increases immunoglobulin A concentrations in breast milk. J Med Food. 2007;10:134-42. PMID:17472477

Substance Identification:

Substance Name:


Scientific Name:

Chlorella sp.

Drug Class:

  • Complementary Therapies

  • Phytotherapy

  • Plants, Medicinal

  • Administrative Information:

    LactMed Record Number:


    Last Revision Date:

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