Keratin
Hasn’t appeared in a scanned product yet.
Talk to your doctor or pharmacist.
Roll Call does not check drug interactions or assess personal safety.
A structural protein rich in sulfur-containing amino acids — the same protein that makes up hair, nails, and the outer layer of skin. Supplement forms are usually hydrolyzed from animal sources such as wool or feathers.
Why it’s used
Taken by some for hair and nail strength or appearance.
What the evidence says
Oral keratin supplementation has been examined only in small, mostly industry-associated trials; there is no robust, independently replicated body of evidence establishing an effect on hair or nail growth from taking it by mouth.
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: 9 records · searched August 2026
"Keratin"[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: 19907 records · searched August 2026
"Keratin"[Title/Abstract]
This says what this database holds under these terms. It is not a finding that no research exists.
Context
Small trials on nail brittleness used daily oral hydrolyzed keratin over several months, but sample sizes were small and results have not been widely replicated.
Educational information, not medical or safety advice. Consult a professional for allergies or medical concerns.