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Head-to-head evidence comparison — which supplement is right for you?
Collagen vs Keratin: Collagen has the stronger overall evidence (6 vs 3/10); they're alternatives for improve skin health — the best pick depends on your goals. Take the 60-second quiz for a pick tailored to your goals.
Collagen wins 2 of 3 categories. Both are solid choices — the best pick depends on your specific goals.
Verdict
Likely helps
6 of 6 studies with measurable effects showed benefit.
Top outcomes
Verdict
Mostly mechanism / observational
Top outcomes
Shared outcomes (1)
Outcomes where both Collagen and Keratin have evidence — compare verdict strength side-by-side.
10-15g
Any time of day, With vitamin C for enhanced synthesis
Hydrolyzed collagen peptides (powder)
~500-1000 mg hydrolyzed/solubilized keratin daily (trial-typical); Cynatine HNS trial used 500 mg keratin plus vitamins/minerals
with-meals
Solubilized keratin (Cynatine HNS) or feather keratin hydrolysate
8-12 weeks
8-12 weeks
12 weeks
First week
~90 days
~90 days
Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials
The American Journal of Medicine (2025) · Meta analysis · n=1474
A total of 23 RCTs with 1474 participants were analyzed.
Effect of collagen supplementation on knee osteoarthritis: an updated systematic review and meta-analysis of randomised controlled trials
Clinical and experimental rheumatology (2025) · Meta analysis · n=870
The meta-analysis revealed an overall significant improvement of both function [MD, -6.46 (95% CI -9.52, -3.40); I2=75%; p=0.00001] and pain scores [MD, -13.63 (95% CI -20.67, -6.58); I2=88%; p=0.00001], favouring collagen supplementation.
Impact of Collagen Peptide Supplementation in Combination with Long-Term Physical Training on Strength, Musculotendinous Remodeling, Functional Recovery, and Body Composition in Healthy Adults: A Systematic Review with Meta-analysis
Sports medicine (Auckland, N.Z.) (2024) · Meta analysis · n=768
This systematic review and meta-analysis represents the first comprehensive investigation into the effects of long-term CP supplementation combined with regular physical training on various aspects of musculoskeletal health in adults.
A clinical trial to investigate the effect of Cynatine HNS on hair and nail parameters.
ScientificWorldJournal (2014) · Rct · n=50
Randomized, double-blind, placebo-controlled trial in 50 women (25 active, 25 placebo)
The Effects of an Oral Supplementation of a Natural Keratin Hydrolysate on Skin Aging: A Randomized, Double-Blind, Placebo-Controlled Clinical Study in Healthy Women.
J Cosmet Dermatol (2025) · Rct
Three-arm RCT: 500 mg or 1000 mg feather keratin hydrolysate vs placebo in adult women
Feather keratin hydrolysates obtained from microbial keratinases: effect on hair fiber.
BMC Biotechnol (2013) · In vitro
Laboratory study producing keratin peptides and testing them in topical hair formulations
Meta-analysis of 23 RCTs (n=1474) found collagen significantly improved skin hydration, elasticity, and wrinkles overall, but high-quality and non-industry-funded studies showed no significant effect. Hydrolyzed collagen peptides preferred for bioavailability.
AI-estimated from published studies. Interpret as directional guidance.
Collagen has a higher evidence score (6/10 vs 3/10) and wins in 2 of 3 categories.
For improve skin health, Collagen has a higher relevance score (85 vs 28).
No known interactions between Collagen and Keratin have been documented in our database. However, always consult a healthcare provider before combining supplements.
The honest tier list — proven staples vs situational vs mostly marketing. The hub the other guides feed into.
Curcumin, omega-3, UC-II collagen, Boswellia vs the old glucosamine default — and OA vs RA.
Modest-but-real for skin, growing for joints, weak for hair/nails — plus which type to buy.
The right pick depends on your goals. Answer a few quick questions for a personalised recommendation — or dig into the full evidence on each.