Chlorella supplements and health effects in people and animals
What it found
Chlorella supplements have been tested for blood pressure, cholesterol, blood sugar, immune effects and more, mostly in small human trials and animal studies.
Some trials found improvements, but the authors say the compounds responsible are still unclear.
What they found
Studies in people
Blood pressure and cholesterol
A meta-analysis of 19 randomized controlled trials in 797 people found Chlorella improved total cholesterol, LDL cholesterol, systolic and diastolic blood pressure, and fasting blood glucose, but not triglycerides or HDL cholesterol.
Blood sugar in people
In a 12-week trial of 28 borderline-diabetic participants, Chlorella lowered the expression of resistin, a gene linked to insulin resistance, compared with placebo.
Immune effects in people
A four-week trial found salivary SIgA rose after Chlorella but not placebo. An eight-week trial in healthy adults found natural killer cell activity increased with Chlorella.
Animal and lab studies
Animal and lab studies
In rats and mice, Chlorella reduced blood pressure, lowered cholesterol, and protected the liver from damage. In lab tests, Chlorella extracts inhibited growth of human colon cancer cells.
Studies in people and animals
Detoxification
In rats, Chlorella increased fecal excretion of dioxins. In a human trial, Chlorella reduced mercury levels in hair and blood.
Other findings
Nutrients in products
Commercial Chlorella products contain about 59% protein by dry weight, all essential amino acids, and more folate and iron than other plant foods. They also contain vitamins D2 and B12, which plants do not make.
What the authors conclude
“Overall, the information regarding bioactive compounds in Chlorella is limited.”
Also in their conclusions
- They say that mounting scientific evidence shows health benefits of daily Chlorella consumption in animal and human studies.
- They note that the beneficial effects might involve synergism between multiple nutrient and antioxidant compounds.
- They conclude that overall, information regarding bioactive compounds in Chlorella is limited, so new compounds may be identified in future studies.
How it was done
The authors wanted to gather updated information on the nutrients and bioactive compounds in Chlorella that may promote human health, because little is known about which compounds are responsible for its effects.
They reviewed published studies on commercially available Chlorella products, including their nutrient content and tests in rats, mice, cells and people. Human trials ranged from 14 to 797 participants and lasted from two weeks to three months.
What it can’t tell you
- Many of the studies were small or done in animals, so the results may not apply to all people.
- The review cannot show which specific compounds in Chlorella cause the effects seen, because the products contain many nutrients and antioxidants.
- For some benefits, such as living longer, no human study has been done.
Who paid
- Conflicts
- The authors declare no conflict of interest.
- Authors work at
- Tottori University, Japan
The paper
- Title
- Potential of Chlorella as a Dietary Supplement to Promote Human Health
- Type
- ReviewThe authors read earlier studies and describe what they found. It isn’t a new study.
- Evidence
- Studies in people · animals · lab
- Summarised from
- Full text
- Licence
- CC BY. Words in quotation marks are the authors’; the rest is our summary.
- Cite
- Bito T, Okumura E, Fujishima M, Watanabe F (2020). Potential of Chlorella as a Dietary Supplement to Promote Human Health. Nutrients. doi:10.3390/nu12092524Free full textPubMed 32825362DOI
Summary written 29 Sep 2026. Check it against the paper before it changes what you eat. How we summarise papers · Report an error