- Arabinose, ARS-2, carotenoids, Chlorella kessleri, Chlorella pyrenoidosa spp., Chlorella seaweed, Chlorella vulgaris spp., chlorophyll, functional food, galactose, Immurella, living food diet, manganese, microalgae, ONC-107, Oocystaceae (family), RespondinÂ®, rhamnose, vitamin B12, vitamin K-rich foods.
- Chlorella spp. (species) are single-celled green algae that reproduce quickly using only carbon dioxide, water, sunlight, and a few minerals. In the 1940s, chlorella was believed to be a “superfood” that could supply calories, fat, vitamins, and the 10 then-known essential amino acids to feed a booming population. Scientists have explored using Chlorella spp. in bioregenerative life-support systems for spacecraft and other closed biological systems, such as Biosphere 2.
- Current interest in chlorella includes using it for boosting the immune system and for detoxification. Because it is able to resist the damaging effects of toxic metals, chlorella may possibly be used to detoxify water, e.g., to remove arsenic from water.
- Two clinical trials studying chlorella’s effects on patients with fibromyalgia have shown positive results, although higher-quality studies are needed for all areas of chlorella research.
These uses have been tested in humans or animals. Safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider.
Fibromyalgia is a chronic musculoskeletal disorder of unknown cause. Limited research suggests that chlorella may have beneficial effects on the tenderness associated with fibromyalgia. Although the results are promising, more high-quality studies are needed before a conclusion can be made.
Limited research has investigated chlorella’s use as an adjunct to cryosurgery. More high-quality research is needed in this area.
Preliminary evidence suggests that ingestion of chlorella may reduce blood pressure in patients with high blood pressure. Further research is needed in this area.
Limited research has investigated the effect of chlorella on skin cancer. Additional high-quality research is needed in this area.
Limited research suggests that chlorella may improve the symptoms of ulcerative colitis (a type of inflammatory bowel disease). More high-quality studies are needed before a conclusion can be made.
Limited research suggests that chlorella may lack an effect on stimulating the immune system when used together with a vaccine. Additional research is needed in this area.
*Key to grades:
The below uses are based on tradition, scientific theories, or limited research. They often have not been thoroughly tested in humans, and safety and effectiveness have not always been proven. Some of these conditions are potentially serious, and should be evaluated by a qualified healthcare provider. There may be other proposed uses that are not listed below.
Adults (18 years and older)
- For fibromyalgia, 10 grams of “Sun Chlorella” tablets and 100 milliliters of liquid “Wakasa Gold” have been taken by mouth daily for two months.
- For high blood pressure, 10 grams of chlorella tablets and 100 milliliters of chlorella extract have been taken by mouth daily for two months.
Children (under 18 years old)
- There is no proven safe or effective dose of chlorella in children.
The below doses are based on scientific research, publications, traditional use, or expert opinion. Many herbs and supplements have not been thoroughly tested, and safety and effectiveness may not be proven. Brands may be made differently, with variable ingredients, even within the same brand. The below doses may not apply to all products. You should read product labels, and discuss doses with a qualified healthcare provider before starting therapy.
- Use cautiously in individuals with known allergy or hypersensitivity to chlorella, its constituents, or members of the Oocystaceae family. Allergy to chlorella has been reported in children sensitized to molds. Occupational asthma induced by chlorella has been reported.
Side Effects and Warnings
- Chlorella is likely safe when used in amounts commonly found in food or for short-term supplementation.
- Chlorella may cause fatigue, gait disturbance, dysarthria (speech disorder), occupational asthma, hyperpigmentation, dermatitis, elevated serum and cerebrospinal fluid manganese (Mn) levels, or swelling followed by red skin lesions on sun-exposed areas of the body, or it may make a patient more sensitive to laser treatment.
- Chlorella may cause low blood pressure. Caution is advised in patients taking drugs, herbs, or supplements that lower blood pressure.
- Chlorella may lower cholesterol levels. Caution is advised in patients taking cholesterol-lowering drugs, herbs, or supplements.
- Use cautiously in patients taking immunomodulators or those with altered immune function, as chlorella may have immunostimulating effects.
- Use cautiously in patients with cancer or those being treated for cancer, as chlorella may have anticancer effects.
- Use cautiously in patients with photosensitivity (sensitivity to light), those taking agents that cause photosensitivity, and those exposed to the sun or undergoing laser treatment.
- Use cautiously in patients monitoring dioxin or cadmium levels, as chlorella may alter dioxin levels or increase cadmium excretion.
- Avoid in patients with bleeding disorders or those taking drugs, herbs, or supplements that may increase the risk of bleeding, as chlorella may increase the risk of bleeding. Dosing adjustments may be necessary. Avoid in patients using warfarin (e.g., CoumadinÂ®) or other anticoagulant therapy, as chlorella contains high amounts of vitamin K and may interfere with blood clotting.
- Avoid in pregnant or breastfeeding women, due to a lack of available scientific evidence.
- Avoid long-term use or using at the same time as manganese, as chlorella contains manganese and has caused manganese-induced parkinsonism, according to a case report.
- Avoid in individuals with known allergy or hypersensitivity to chlorella, its constituents, molds, or members of the Oocystaceae family.
Pregnancy and Breastfeeding
- Avoid in pregnant or breastfeeding women, due to a lack of available scientific evidence.
The U.S. Food and Drug Administration does not strictly regulate herbs and supplements. There is no guarantee of strength, purity or safety of products, and effects may vary. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy. Consult a healthcare provider immediately if you experience side effects.
Interactions with Drugs
- Chlorella may increase the risk of bleeding when taken with anticoagulants (blood thinners) and drugs that increase the risk of bleeding, particularly warfarin (CoumadinÂ®) and heparin. Other examples include aspirin, antiplatelet drugs such as clopidogrel (PlavixÂ®), and nonsteroidal anti-inflammatory drugs such as ibuprofen (MotrinÂ®, AdvilÂ®) or naproxen (NaprosynÂ®, AleveÂ®).
- Chlorella may low blood pressure. Caution is advised in patients taking drugs that lower blood pressure.
- Chlorella may also interact with anticancer agents, anti-inflammatories, cholesterol-lowering agents, dioxin-detoxifying drugs, heavy metal antagonists or chelating agents, immunosuppressants, photosensitizing agents, and some vaccines.
Interactions with Herbs and Dietary Supplements
- Chlorella may increase the risk of bleeding when taken with herbs and supplements that are believed to increase the risk of bleeding. Multiple cases of bleeding have been reported with the use of Ginkgo biloba, and fewer cases with garlic and saw palmetto. Numerous other agents may theoretically increase the risk of bleeding, although this has not been proven in most cases.
- Chlorella may cause low blood pressure. Caution is advised in patients taking herbs or supplements that lower blood pressure.
- Chlorella may also interact with anticancer agents, anti-inflammatory herbs and supplements, antioxidants, cholesterol-lowering agents, dioxin-detoxifying agents, heavy metal antagonists or chelating agents, immunosuppressants, manganese, photosensitizing agents, vitamin K, and vitamin K-containing foods.
Most herbs and supplements have not been thoroughly tested for interactions with other herbs, supplements, drugs, or foods. The interactions listed below are based on reports in scientific publications, laboratory experiments, or traditional use. You should always read product labels. If you have a medical condition, or are taking other drugs, herbs, or supplements, you should speak with a qualified healthcare provider before starting a new therapy.
- This information is based on a systematic review of scientific literature edited and peer-reviewed by contributors to the Natural Standard Research Collaboration ().
- Chu CY, Huang R, Ling LP. Purification and characterization of a novel haemagglutinin from Chlorella pyrenoidosa. J Ind Microbiol Biotechnol 2006;33(11):967-973.
- Csonto J, Kadukova J, Polak M. Artificial life simulation of living alga cells and its sorption mechanisms. J Med Syst 2001;25(3):221-231.
- 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(2):111-117.
- Honek L, Uzel R, Fialova L, et al. [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.
- Ivanova IE, Derendiaeva TA, Alekhina TP, et al. [The role of higher plants in the human biological life support system]. Kosm Biol Aviakosm Med 1990;24(4):40-43.
- Kralovec JA, Metera KL, Kumar J.R, et al. Immunostimulatory principles from Chlorella pyrenoidosa–part 1: isolation and biological assessment in vitro. Phytomedicine 2007;14(1):57-64.
- Merchant RE, Andre CA. 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.
- Merchant RE, Andre CA, Sica DA. Nutritional supplementation with Chlorella pyrenoidosa for mild to moderate hypertension. J Med Food 2002;5(3):141-152.
- Ohkawa S, Yoneda Y, Ohsumi Y, et al. [Warfarin therapy and chlorella]. Rinsho Shinkeigaku 1995;35(7):806-807.
- Ohtake T, Negishi K, Okamoto K, et al. Manganese-induced Parkinsonism in a patient undergoing maintenance hemodialysis. Am J Kidney Dis 2005;46(4):749-753.
- Rauma AL, Torronen R, Hanninen O, et al. Vitamin B-12 status of long-term adherents of a strict uncooked vegan diet (“living food diet”) is compromised. J Nutr 1995;125(10):2511-2515.
- Salisbury FB. Joseph I. Gitelson and the Bios-3 project. Life Support Biosph Sci 1994;1(2):69-70.
- Schnitzler S, Rathsack R. [Reaction of anti-A-hemagglutinin from Helix pomatia with algae (Chlorella pyrenoidosa) and demonstration of heterophilic agglutinins against algae in human sera]. Acta Biol Med Ger 1974;33(1):121-127.
- Tiberg E, Dreborg S, Bjorksten B. Allergy to green algae (Chlorella) among children. J Allergy Clin Immunol 1995;96(2):257-259.
- Tiberg E, Einarsson R. Variability of allergenicity in eight strains of the green algal genus Chlorella. Int Arch Allergy Appl Immunol 1989;90(3):301-306.
Natural Standard developed the above evidence-based information based on a thorough systematic review of the available scientific articles. For comprehensive information about alternative and complementary therapies on the professional level, go to . Selected references are listed below.