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.


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.

Chlorella is used to prevent low levels of iron in women who are pregnant. It is also used for depression, menstrual cramps, fibromyalgia, high cholesterol, and other conditions, but there is no good scientific evidence to support these uses.

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

  • Low levels of iron in women who are pregnant. 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

  • High blood pressure during pregnancy. Early research shows that taking chlorella during pregnancy does not reduce the risk of high blood pressure.

Insufficient Evidence for

  • Brain tumor. Early research shows that taking chlorella tablets plus chlorella liquid extract might help people with a type of brain tumor called glioma better tolerate chemotherapy and radiation treatments. But chlorella does not seem to slow the progression of the cancer or improve survival.
  • 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.
  • Menstrual cramps (dysmenorrhea). Early research shows that taking chlorella soft gels for 8 weeks might decrease pain in women with menstrual cramps.
  • Airway infections caused by exercise. Early research shows that taking chlorella tablets for 6 weeks might strengthen the immune system. But it doesn't seem to prevent airway infections caused by exercise.
  • Fatigue. Early research shows that taking chlorella for 4 weeks doesn't seem to reduce fatigue after exercise or during rest.
  • 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.
  • Swelling (inflammation) of the liver caused by the hepatitis C virus (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 levels of cholesterol or other fats (lipids) in the blood (hyperlipidemia). 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.
  • Build up of fat in the liver in people who drink little or no alcohol (nonalcoholic fatty liver disease or NAFLD). Early research shows that taking chlorella with metformin and vitamin E for 3 months might improve markers of liver injury in people with NAFLD.
  • A grouping of symptoms that increase the risk of diabetes, heart disease, and stroke (metabolic syndrome).
  • A sexually transmitted infection caused by Trichomonas vaginalis (trichomoniasis).
  • A type of inflammatory bowel disease (Crohn disease).
  • A type of inflammatory bowel disease (ulcerative colitis).
  • Aging.
  • Asthma.
  • Bad breath.
  • Bed sores (pressure ulcers).
  • Cancer.
  • Certain infections (opportunistic infections) in people with HIV/AIDS.
  • Common cold.
  • Constipation.
  • Damage to the immune system caused by cancer drug treatment.
  • Foot sores in people with diabetes.
  • Indigestion (dyspepsia).
  • Infections in people treated with cancer drugs.
  • Lead poisoning.
  • Leg sores caused by weak blood circulation (venous leg ulcer).
  • Mercury poisoning.
  • Premenstrual syndrome (PMS).
  • Skin damage caused by radiation therapy (radiation dermatitis).
  • Stomach ulcers.
  • Tiredness in people treated with cancer drugs.
  • Ulcers.
  • Other conditions.
More evidence is needed to rate the effectiveness of chlorella for these uses.

Side Effects

Side Effects & Safety

When taken by mouth: 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.

When applied to the skin: There isn't enough reliable information to know if chlorella is safe or what the side effects might be when applied to the skin.

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.

    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 low iron levels in women who are pregnant: 2 grams three times daily has been taken from the 12-18th week of gestation, until delivery.

View References


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  • 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.
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