Roll Call

“Chlorella?”Here!chlorella algae

Plant

Hasn’t appeared in a scanned product yet.

As a supplement

Talk to your doctor or pharmacist.

Roll Call does not check drug interactions or assess personal safety.

A single-celled freshwater green algae grown and dried into powder or tablet form, sold as a whole-food supplement.

Why it’s used

Taken as a general nutritional supplement, often for its chlorophyll, protein, and micronutrient content, and sometimes marketed for detoxification support.

What the evidence says

Small human trials have looked at chlorella for markers like blood lipids, blood pressure, and immune measures, with mixed and generally modest results. There is no NIH Office of Dietary Supplements fact sheet on chlorella, and no large, well-controlled trial has established a clear health benefit for a specific outcome.

Where we looked

There was no paper to cite here, so this is the search instead — run it yourself and see what we saw.

  • PubMed: 1894 records · searched September 2026"Chlorella"[Title/Abstract] AND (review[pt] OR "safety assessment"[Title/Abstract] OR "risk assessment"[Title/Abstract] OR toxicology[Title/Abstract] OR toxicity[Title/Abstract] OR characterization[Title/Abstract] OR characterisation[Title/Abstract])
  • PubMed: 38 records · searched September 2026"Chlorella"[Title/Abstract] AND ("dietary supplements"[MeSH] OR supplementation[Title/Abstract] OR supplement[Title/Abstract] OR supplements[Title/Abstract] OR "oral administration"[Title/Abstract]) AND (randomized controlled trial[pt] OR clinical trial[pt] OR meta-analysis[pt] OR systematic review[pt]) AND humans[MeSH]
  • PubMed: 9741 records · searched September 2026"Chlorella"[Title/Abstract]

This says what this database holds under these terms. It is not a finding that no research exists.

Context

Studies have used a range of forms (tablets, powder) and doses, making comparison difficult; most trials are small and short in duration.

Insufficient dataToo little has been studied to say either way.

Rumors

  1. Taking chlorella clears skin and reduces acne breakouts.

    We haven’t found evidence strong enough to support this or rule it out.

    What was measured is not yet noted.

    Who’s saying this

    • HUM — a brand: sells nutritional supplements
      How we know who this is
      • “HUM’s mission is to help you find your confidence and feel good in your skin and body.” (their page)
      • “HUM hired scientists, began to explore people’s diverse issues and find ways to solve for those individual struggles by developing nutritional solutions that target very specific skin, hair, body and mood needs.” (their page)
  2. Chlorella supplements are contaminated with liver toxins and neurotoxins.

    We haven’t found evidence strong enough to support this or rule it out.

    What was measured is not yet noted.

    Who’s saying this

    • NutritionFacts.org — an advocacy group: promotes whole food, plant-based diet; nonprofit
      How we know who this is
      • “NutritionFacts.org is a science-based nonprofit charity committed to bringing the medical literature to you, breaking down the latest in evidence-based nutrition research, and presenting the results in ways that are easy to understand.” (their page)
      • “We also disseminate fact-based information through social media on the benefits of a whole food, plant-based diet for wellness, disease prevention, healthy weight management, and longevity.” (their page)
  3. Chlorella removes heavy metals such as mercury, lead and cadmium from the body by binding (chelating) them.

    Supports — suggestivehealth and safety evidence

    Studied in: adults with long-term dental titanium implants and amalgam fillings.

    Measured as a biomarker.

    Who’s saying this

    • ENERGYbits® — a brand: sells spirulina and chlorella algae tablets
      How we know who this is
      • “Catharine Arnston started ENERGYbits® after her sister was diagnosed with breast cancer and advised by her oncologist that an alkaline diet would help her heal.” (their page)
      • “We're glad she finally did, because now you and your family can benefit from our naturally grown, toxin-free, Non-GMO algae tablets too.” (their page)
  4. Chlorella is harmful for people with thyroid problems because it contains iodine and can trigger autoimmune conditions.

    We haven’t found evidence strong enough to support this or rule it out.

    What was measured is not yet noted.

    Who’s saying this

    • HealthUnlocked — a platform — posts are by its users: health communities social network; offers research and clinical trial participation opportunities
      How we know who this is
      • “HealthUnlocked brings together supportive communities, shared experiences, and opportunities to take part in health research.” (their page)
  5. Chlorella boosts the immune system.

    Supports — suggestivehealth and safety evidence

    Measured as a biomarker.

    Who’s saying this

    • MedicineNet — a publisher: health media publishing; acquired by WebMD
      How we know who this is
      • “MedicineNet is an online, healthcare media publishing company.” (their page)
      • “WebMD acquired MedicineNet in 2004.” (their page)