Algue Verte d’Eau Douce, Bulgarian Chlorella, Bulgarian Green Algae, Chinese Chlorella, Chlorella Algae, Chlorella pyrenoidosa, Chlorella vulgaris, Chlorelle, Clorela, Freshwater Green Algae, Freshwater Seaweed, Green Alga, Green Algae, Japanese Chlorella, Seaweed, Yaeyama Chlorella.<br/><br/>


Overview Information

Chlorella is a type of algae that grows in fresh water. The whole plant is used to make nutritional supplements and medicine.

Most of the chlorella that is available in the U.S. is grown in Japan or Taiwan. It is processed and made into tablets and liquid extracts. These extracts contain “chlorella growth factor,“ which is described as a water-soluble extract of chlorella containing chemicals including amino acids, peptides, proteins, vitamins, sugars, and nucleic acids.

Be aware that chlorella products can vary significantly depending on the way “the crop“ used to make them was cultivated, harvested, and processed. Investigators have found that dried preparation of chlorella can contain from 7% to 88% protein, 6% to 38% carbohydrate, and 7% to 75% fat.

Some people take chlorella by mouth for high blood pressure, high cholesterol, metabolic syndrome, depression, for preventing cancer, reducing radiation or chemotherapy treatment side effects, for hepatitis C, ““‘and for a muscle disorder called fibromyalgia.

In pregnant females, chlorella is used to prevent pregnancy associated anemia (low iron) and high blood pressure.

How does it work?

Chlorella is a good source of protein, fats, carbohydrates, fiber, chlorophyll, vitamins, and minerals. It may act as an antioxidant and help to decrease cholesterol, but more research is still needed.


Uses & Effectiveness?

Possibly Effective for

  • Iron deficiency during pregnancy. Early research shows that taking chlorella might reduce the risk of anemia caused by too little iron in the body when taken by women who are pregnant.

Possibly Ineffective for

  • Pregnancy-induced high blood pressure. Early research shows that taking chlorella during pregnancy does not reduce the risk of high blood pressure (gestational hypertension).

Insufficient Evidence for

  • Depression. Early research shows that taking chlorella extract tablets for 6 weeks, in addition to already prescribed antidepressant medications, may improve some symptoms of depression and anxiety in patients with major depression disorder.
  • Fibromyalgia. Some people with fibromyalgia say they feel better when they take chlorella tablets plus a liquid extract containing malic acid daily for 2 months.
  • Brain tumor (gilioma). Early research shows that taking chlorella tablets plus chlorella liquid extract might help people with a type of brain cancer called glioma better tolerate chemotherapy and radiation treatments. However, chlorella does not seem to slow the progression of the cancer or improve survival.
  • Hepatitis C. Early research shows that taking chlorella for 12 weeks improves liver inflammation but does not decrease levels of the hepatitis C virus in the blood.
  • High cholesterol. Early research shows that taking chlorella for 4 weeks decreases total cholesterol and triglycerides but does not decrease LDL "bad" cholesterol or increase HDL "good" cholesterol.
  • High blood pressure. Early research shows that taking chlorella daily for 1-2 months does not reduce blood pressure in people with high blood pressure.
  • Metabolic syndrome. Early research shows that taking a product containing a combination of red yeast rice, bitter melon, chlorella, licorice, and soy protein for 12 weeks decreases total cholesterol, LDL "bad" cholesterol, and triglyceride levels, but does not improve waist circumference, HDL "good" cholesterol, or blood sugar levels.
  • Bad breath.
  • Cancer prevention.
  • Colds.
  • Constipation.
  • Crohn's disease.
  • Ulcerative colitis.
  • Ulcers.
  • Other conditions.
More evidence is needed to rate the effectiveness of chlorella for these uses.

Side Effects

Side Effects & Safety

Chlorella is LIKELY SAFE when taken by mouth, short-term (up to 29 weeks). The most common side effects include diarrhea, nausea, gas (flatulence), green discoloration of the stools, and stomach cramping, especially in the two weeks of use.

Chlorella can cause skin to become extra sensitive to the sun. Wear sunblock outside, especially if you are light-skinned.

Special Precautions & Warnings:

Pregnancy and breast-feeding: Chlorella is POSSIBLY SAFE when taken by mouth appropriately during pregnancy. There is not enough reliable information about the safety of taking chlorella if you are breast feeding. Stay on the safe side and avoid use.

Allergy to molds: Chlorella might cause an allergic reaction in people who are also allergic to molds.

Weak immune system (immunodeficiency): There is a concern that chlorella might cause “bad” bacteria to take over in the intestine of people who have a weak immune system. Do not use chlorella or use with caution if you have this problem.

Iodine sensitivity: Chlorella can contain iodine. Therefore, chlorella might cause an allergic reaction in people sensitive to iodine.



Moderate Interaction

Be cautious with this combination

  • Medications that decrease the immune system (Immunosuppressants) interacts with CHLORELLA

    Chlorella might increase the immune system. By increasing the immune system, chlorella might decrease the effectiveness of medications that are used to decrease the immune system.<br/><br/> Some medications that decrease the immune system include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), corticosteroids (glucocorticoids), and others.

  • Warfarin (Coumadin) interacts with CHLORELLA

    Chlorella contains large amounts of vitamin K. Vitamin K is used by the body to help blood clot. Warfarin (Coumadin) is used to slow blood clotting. By helping the blood clot, chlorella might decrease the effectiveness of warfarin (Coumadin). Be sure to have your blood checked regularly. The dose of your warfarin (Coumadin) might need to be changed.



The following doses have been studied in scientific research:



  • For iron deficiency during pregnancy: Chlorella (Sun Chlorella A by Sun Chlorella Corp.) 2 grams three times daily has been taken from the 12-18th week of gestation, until delivery.

View References


  • Cheng, F. C., Lin, A., Feng, J. J., Mizoguchi, T., Takekoshi, H., Kubota, H., Kato, Y., and Naoki, Y. Effects of chlorella on activities of protein tyrosine phosphatases, matrix metalloproteinases, caspases, cytokine release, B and T cell proliferations, and phorbol ester receptor binding. J.Med.Food 2004;7(2):146-152. View abstract.
  • Hasegawa, T., Matsuguchi, T., Noda, K., Tanaka, K., Kumamoto, S., Shoyama, Y., and Yoshikai, Y. Toll-like receptor 2 is at least partly involved in the antitumor activity of glycoprotein from Chlorella vulgaris. Int.Immunopharmacol. 2002;2(4):579-589. View abstract.
  • Honek, L., Uzel, R., Fialova, L., and Sracek, J. [The use of a fresh-water weed Chlorella vulgaris for the treatment of the cervix after kryo-surgical interventions (author's transl)]. Cesk.Gynekol. 1978;43(4):271-273. View abstract.
  • Ichimura, S. [Effect of chlorella on skin cancer of Black Foot patients in south Formosa]. Nippon Eiseigaku Zasshi 1975;30(1):66. View abstract.
  • Kralovec, J. A., Metera, K. L., Kumar, J. R., Watson, L. V., Girouard, G. S., Guan, Y., Carr, R. I., Barrow, C. J., and Ewart, H. S. Immunostimulatory principles from Chlorella pyrenoidosa--part 1: isolation and biological assessment in vitro. Phytomedicine 2007;14(1):57-64. View abstract.
  • Merchant, R. E. and Andre, C. A. A review of recent clinical trials of the nutritional supplement Chlorella pyrenoidosa in the treatment of fibromyalgia, hypertension, and ulcerative colitis. Altern.Ther.Health Med. 2001;7(3):79-91. View abstract.
  • Merchant, R. E., Andre, C. A., and Sica, D. A. Nutritional supplementation with Chlorella pyrenoidosa for mild to moderate hypertension. J.Med.Food 2002;5(3):141-152. View abstract.
  • Ohkawa, S., Yoneda, Y., Ohsumi, Y., and Tabuchi, M. [Warfarin therapy and chlorella]. Rinsho Shinkeigaku 1995;35(7):806-807. View abstract.
  • Ohtake, T., Negishi, K., Okamoto, K., Oka, M., Maesato, K., Moriya, H., and Kobayashi, S. Manganese-induced Parkinsonism in a patient undergoing maintenance hemodialysis. Am J Kidney Dis 2005;46(4):749-753. View abstract.
  • Pugh, N., Ross, S. A., ElSohly, H. N., ElSohly, M. A., and Pasco, D. S. Isolation of three high molecular weight polysaccharide preparations with potent immunostimulatory activity from Spirulina platensis, aphanizomenon flos-aquae and Chlorella pyrenoidosa. Planta Med. 2001;67(8):737-742. View abstract.
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  • Davis DR. Some algae are potentially adequate sources of vitamin B-12 for vegans (letter, comment). J Nutr 1997;127:378,380.
  • Halperin SA, Smith B, Nolan C, et al. Safety and immunoenhancing effect of a Chlorella-derived dietary supplement in healthy adults undergoing influenza vaccination: randomized, double-blind, placebo-controlled trial. CMAJ 2003;169:111-7.. View abstract.
  • Jitsukawa K, Suizu R, Hidano A. Chlorella photosensitization. New phytophotodermatosis. Int J Dermatol 1984;23:263-8. View abstract.
  • Konishi F, Tanaka K, Himeno K, et al. Antitumor effect induced by a hot water extract of Chlorella vulgaris (CE): resistance to Meth-A tumor growth mediated by CE-induced polymorphonuclear leukocytes. Cancer Immunol Immunother 1985;19:73-8. View abstract.
  • Krcmery V Jr. Systemic chlorellosis, an emerging infection in humans caused by algae. Int J Antimicrob Agents 2000;15:235-7.. View abstract.
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  • Lee IT, Lee WJ, Tsai CM, Su IJ, Yen HT, Sheu WH. Combined extractives of red yeast rice, bitter gourd, chlorella, soy protein, and licorice improve total cholesterol, low-density lipoprotein cholesterol, and triglyceride in subjects with metabolic syndrome. Nutr Res. 2012;32(2):85-92. View abstract.
  • Merchant RE, Carmack CA, Wise CM. Nutritional supplementation with Chlorella pyrenoidosa for patients with fibromyalgia syndrome: a pilot study. Phytother Res 2000;14:167-73. View abstract.
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