Chlorella (Chlorella pyrenoidosa) is a freshwater, single-cell, green algae used to make supplements and as a natural remedy. It's marketed as a "superfood" with powerful health benefits, but science doesn't necessarily support the hype.
Chlorella Health Claims
According to WebMD, chlorella sold in the United States comes from Japan or Taiwan. The entire plant is used to make medicine.
Chlorella supplements contain chlorella growth-factor (CGF), a nutrient-dense, water-soluble substance believed to boost immunity. CGF is made of amino acids, peptides, proteins, vitamins, minerals, sugars, and nucleic acids.
Chlorella is marketed to treat a variety of health conditions. These include:
- High blood pressure
- High cholesterol
- Digestive disorders, such as Crohn's disease and ulcers
Don't confuse chlorella with spirulina, another freshwater algae rich in nutrients and chlorophyll. Spirulina is also considered a "superfood," but it is a blue-green algae. Chlorella and spirulina are sometimes found together in supplement products.
Despite many natural health enthusiasts' claims that chlorella is a superfood, research supporting those claims is mixed.
- Chlorella may help detox the body from heavy metals. One study on rats showed it counteracts heavy metal poisoning and "decreases tissue damage by decreasing cadmium absorption." According to natural medicine expert Dr. Josh Axe's website, chlorella wraps itself around heavy metals, preventing them from being absorbed.
- According to Dr. Andrew Weil, laboratory and animal research showed chlorella may have cancer fighting abilities, but there's no evidence it treats cancer in humans.
- A study published in the Canadian Medical Association Journal did not show chlorella boosts immunity after flu shots, although antibody response increased in participants between 50 and 55 years old.
- A review of clinical trials published in Alternative Therapies in Health and Medicine concluded that taking chlorella may reduce blood pressure, reduce cholesterol, accelerate wound healing, and boost immunity.
Chlorella Side Effects and Precautions
WebMD indicates chlorella is "likely safe" when taken orally for up to two months. Some side effects are believed to occur as part of the normal detoxification process. Side effects may include:
- Green stools
- Stomach cramping
- Allergic reaction, including breathing issues and asthma
- Sun sensitivity
Pregnant or breastfeeding women should not use chlorella. Use chlorella with caution if any of the following apply:
- You are allergic to iodine
- You are allergic to mold
- Your immune system is weak
- You have an autoimmune disease, such as lupus, multiple sclerosis, or rheumatoid arthritis
Chlorella may interfere with the following medications:
- Medications that slow blood clotting
Chlorella is available in tablet, powder, and liquid extract forms. WebMD states there is not enough scientific evidence to support a standard dose of chlorella. Dosage recommendations vary among products, so you should check with your doctor, pharmacist, or a natural health practitioner before using.
In a study of the benefits of chlorella on fibromyalgia published in Phytotherapy Research, participants were given 10 grams of "Sun Chlorella" tablets and 100 milliliters of liquid "Wakasa Gold" daily for two months. Symptoms improved in some patients.
Chlorella powder can be added to water, juice, or smoothies. You can also sprinkle it on salads or soup.
Where to Buy
When purchasing chlorella, look for "broken cell" varieties. Chlorella's outer cell wall is difficult to digest, so it's broken to make absorption and digestion easier. Supplements like chlorella are not regulated by the Food and Drug Administration, and quality and content varies among brands. As a result, you should only purchase chlorella from a brand you trust. Here are some options:
- Now Foods, Certified Organic Chlorella contains only organic broken-cell chlorella tablets, 500 mg each. It's vegan and gluten-free. A 200-tablet bottle costs about $13.
- Green Foods Organic Chlorella Powder is great to add to smoothies. This 2.1 ounce jar costs about $13.
- Sun Chlorella Tablets or Granules have no artificial colors, flavors, or chemicals. You can purchase a 20 to 100-day supply. A 20-day supply of tablets or granules costs around $33.
More Research Needed
Despite some studies showing chlorella may have potent health benefits, scientific studies on humans are lacking or inconclusive, as with many natural remedies. However, this does not mean chlorella isn't effective or that anecdotal claims are wishful thinking. Until more research solves the debate, check with your doctor before using chlorella to see if it's a good choice for you.