Oral keratin,
does it really help with Hair and nails?
research showsOral keratin has RCT signals for hair and nail measures from specific hydrolyzed keratin ingredients such as Cynatine HNS. However, positive evidence is concentrated around specific ingredients, manufacturer-linked research lines, and cosmetic measures, with insufficient independent replication.
ads claimAdvertisements mention "edible keratin," "hair structural protein," and "nail strengthening." The research evidence is tied not to general keratin protein but to a specific hydrolyzed/solubilized ingredient and dose.
Useful facts when choosing a product
- The representative study dose is Cynatine HNS 500 mg/day for 90 days.
- For wool-derived ingredients, wool or lanolin allergy and ingredient source may need to be checked.
- This is not interpreted as the same evidence as RCTs of treatments for hair-loss diseases.
- For products containing biotin, zinc, and vitamin combinations, it is difficult to isolate the effect of keratin alone.
Chamgap Semantic Classification Code
Candidate index · review held
UNK.keratin.oral.hair-and-nails.assess.placeboUnknown > Keratin > Oral > Hair and nails > Association or change assessment > Placebo
An automated migration candidate, not an issued permanent code; exact claim scope remains under review. This machine-generated migration candidate helps retrieval but is not a permanent assignment. The original verdict ID and URL remain authoritative.
What the research actually shows
The Cynatine HNS 500 mg/day 90-day study is repeatedly cited for signals of improvement in hair loss, hair growth, strength, shine, and nail measures. However, this evidence is not a large independent RCT that is easily indexed in PubMed; it is identified as a small product-study line for a specific ingredient, and limitations remain regarding ingredient supply, manufacturer interests, and small cosmetic measures. Independent large repeated studies using the same ingredient and dose are limited.
Why this is classified as C (44)
There is a direct cosmetic-measure RCT signal, but it is concentrated in a specific ingredient, manufacturer funding, and small studies, so this is C at 44 points.
Counterpoint. Deficiency-related hair loss or disease-related hair loss requires cause diagnosis and separate treatment evidence.
Rejudgment record. Draft — Positive small RCTs for a specific ingredient, but no independent replication and concentration of manufacturer funding
Cross-check — AI research and Codex final gate
Evidence Table
| Study | Design | Sample | Funding | Endpoint | Result | Weight |
|---|---|---|---|---|---|---|
| Cynatine HNS product study, 2014 | Repeatedly cited randomized placebo-controlled product study | Ingredient manufacturer-related | Hair loss, growth, strength, shine, and nail measures | Reported improvement in hair and nail measures after Cynatine HNS 500 mg/day for 90 days. | Core | |
| Guo EL & Katta R 2017 | Dermatology nutrition literature review | Academic | Nutritional deficiency, supplements, and hair | Summarized the need to separate deficiency/disease causes from general supplement efficacy in hair problems. | Supporting |
Receipt — 3 References
All 3 cited sources were verified for existence at the original page (as of 2026-07-10).
Final verification and publication gate: Codex · Evidence date: 2026-07-10 · Corrections: none
Cite this verdict
[Chamgap] Oral keratin x hair and nails — Evidence Grade C·44. 3 cited sources checked. Source: https://chamgap.com/en/verdicts/skin-hair/oral-keratin-hair-nails/ · CC BY 4.0CC BY 4.0 — free to use with attribution; do not distort grades, numbers, or verdict meaning.
What this document does and does not do
Chamgap is an information source. It reports what research has and has not confirmed; it does not tell readers what to take or buy. That decision belongs to readers and, when needed, medical or legal professionals. This verdict reflects literature available up to the search date and may change as new research appears. Nothing here is medical advice.