Silk amino acids (silk protein)
Silk amino acids and hydrolysed silk are broken-down silkworm proteins used to condition hair and skin in products, and the Cosmetic Ingredient Review panel judged most silk protein ingredients safe as used, but we found no trial showing they improve hair or skin. The human evidence that exists is for other silk materials: small trials of fibroin dressings and sericin cream, mostly on wounds and burns. The main caution is allergy, since silk can cause asthma and, rarely, skin and suture reactions.
At a glance
Last reviewed 30 September 2026What it's used for
Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.
| Use | Evidence | What the research shows |
|---|---|---|
| Hair and skin conditioning in cosmetic products | Traditional | The Cosmetic Ingredient Review panel describes Hydrolyzed Silk and nine other silk protein ingredients as functioning mainly as skin and hair conditioning agents and bulking agents. Its assessment is a safety review, not an efficacy review, and we found no human trial of hydrolysed silk or silk amino acids improving hair strength, shine or skin hydration. The only tie between silk protein and hair we opened was a safety study (see the allergy row). Rated 1 as a long-standing cosmetic use with no clinical testing we could find.1,4 |
| Wound and burn dressings (silk fibroin) | Limited | This is a medical device use of the silk protein fibroin, not the cosmetic ingredient. A 2017 randomised trial of 71 patients found a silk fibroin film shortened healing time and adverse events compared with a commercial dressing. A 2015 trial of a silk and gelatin dressing on 23 skin graft donor sites found healing in 11 days against 14 with a standard dressing. A 2025 systematic review of nine studies on burns and donor sites found silk dressings comparable to existing dressings and called for larger, better studies; that journal has since issued an expression of concern about the paper. Rated 2 for small trials with mixed comparators.8,7,9 |
| Sericin cream for dry or itchy skin and burns | Limited | Sericin is the other main silk protein. In a 2012 double-blind trial in 50 haemodialysis patients, sericin cream improved skin hydration and itching over 6 weeks compared with cream base on the other limb. In a 2013 trial of 29 patients with burns covering at least 15% of the body, adding sericin to silver zinc sulfadiazine cream cut complete healing from about 29 to about 22 days (p = 0.001). Both trials came from the same research group and were small. A 2025 review says sericin looks promising in atopic dermatitis and psoriasis, but it is largely drawing on preclinical work.6,5,10 |
| Allergy to silk proteins (harm signal) | Limited | Not a use but a risk. In 871 children in rural China, skin-prick reactivity to silk was an independent predictor of asthma (odds ratio 2.6, 95% CI 1.2 to 5.7). One case report describes recurrent granulomas that may have been an IgE-mediated reaction to silk fibroin from braided sutures. A separate study of protein hydrolysates in hair conditioners found contact urticaria, mostly to a hydrolysed collagen, and mainly in people with atopic dermatitis; silk was among those tested, but the abstract does not say it caused reactions. These data say silk can sensitise some people, but they do not tell us how often a hydrolysed silk ingredient in a product does.2,3,4 |
How much
Ranges below are what studies used and what supplements commonly contain. They are not a recommendation for you. Start at the low end.
How people take it
Safety
Who should avoid
- Known silk allergy — skin-prick reactivity to silk was linked to asthma
- Silk-triggered asthma or rhinitis — silk sensitisation is linked to asthma
- Atopic dermatitis — protein hydrolysates in hair products caused hives in some people
- Two listed ingredients lacked enough safety data — MEA-hydrolyzed silk and silkworm cocoon extract
Known interactions
Questions people ask
What are silk amino acids?
They are silk protein broken into smaller pieces and used to condition hair and skin in products. The Cosmetic Ingredient Review panel grouped hydrolysed silk and nine other silk protein ingredients as skin and hair conditioning and bulking agents. That review does not list 'silk amino acids' by name, so the sources we opened cover the hydrolysed silk family rather than that exact label.
Are silk amino acids and silk protein safe?
The Cosmetic Ingredient Review panel concluded 8 of 10 silk protein ingredients are safe in the present practices of use and concentration, and that data were insufficient for MEA-hydrolyzed silk and silkworm cocoon extract. The main risk is allergy: skin-prick reactivity to silk was linked to asthma in 871 children in China, and there are case reports of reactions to silk fibroin sutures. People with atopic skin may also react to protein hydrolysates in hair conditioners.
Do silk proteins help hair or skin?
We found no trial showing that hydrolysed silk or silk amino acids improve hair or skin. The human evidence is for other silk materials: small trials of fibroin dressings and sericin creams on wounds, burns and itching. Those results do not show a cosmetic benefit from a conditioner containing silk protein.
Sources
- Safety assessment Johnson W Jr, Bergfeld WF, Belsito DV, et al. Safety Assessment of Silk Protein Ingredients as Used in Cosmetics. Int J Toxicol. 2020.
- Cross-sectional study Celedon JC, Palmer LJ, Xu X, Wang B, Fang Z, Weiss ST. Sensitization to silk and childhood asthma in rural China. Pediatrics. 2001.
- Case report Kurosaki S, Otsuka H, Kunitomo M, Koyama M, Pawankar R, Matumoto K. Fibroin allergy. IgE mediated hypersensitivity to silk suture materials. Nihon Ika Daigaku Zasshi. 1999.
- Clinical study Niinimaki A, Niinimaki M, Makinen-Kiljunen S, Hannuksela M. Contact urticaria from protein hydrolysates in hair conditioners. Allergy. 1998.
- Randomised controlled trial Aramwit P, Palapinyo S, Srichana T, Chottanapund S, Muangman P. Silk sericin ameliorates wound healing and its clinical efficacy in burn wounds. Arch Dermatol Res. 2013.
- Randomised controlled trial Aramwit P, Keongamaroon O, Siritientong T, Bang N, Supasyndh O. Sericin cream reduces pruritus in hemodialysis patients: a randomized, double-blind, placebo-controlled experimental study. BMC Nephrol. 2012.
- Randomised controlled trial Hasatsri S, Angspatt A, Aramwit P. Randomized Clinical Trial of the Innovative Bilayered Wound Dressing Made of Silk and Gelatin: Safety and Efficacy Tests Using a Split-Thickness Skin Graft Model. Evid Based Complement Alternat Med. 2015.
- Randomised controlled trial Zhang W, Chen L, Chen J, et al. Silk Fibroin Biomaterial Shows Safe and Effective Wound Healing in Animal Models and a Randomized Controlled Clinical Trial. Adv Healthc Mater. 2017.
- Systematic review Vermoesen L, De Decker I, Verbelen J, et al. The use of silk dressings in the treatment of skin injuries: A systematic review. Burns. 2025.
- Review Stradczuk-Mazurek M, Mazurek L, Konop M. Silk Sericin in Dermatological Diseases: From Preclinical Studies to Future Clinical Applications. Macromol Biosci. 2025.
Last reviewed 30 September 2026 · Next review March 2027 · How we rate evidence
Reader notes
Experiences and questions from readers, read by an editor before they appear. They are personal accounts, not evidence, and are not medical advice.