Collagen peptides
Hydrolysed collagen / collagen hydrolysate · Performance
Digested to amino acids like any protein — yet the skin and tendon trials keep coming out mildly positive anyway.
What the evidence says
The obvious objection is right — you digest collagen into amino acids, so eating it does not send collagen to your skin. Despite that, meta-analyses of skin trials report small but consistent improvements in elasticity and hydration, and the proposed mechanism is that specific di- and tri-peptides survive digestion and act as signals. Joint and tendon findings are weaker and less consistent. Treat it as a modest, real, and mechanistically odd effect rather than the transformation the marketing sells.
What studies used
Skin trials commonly used 2.5–10 g/day; tendon and joint protocols in studies used around 15 g. Tendon studies paired it with vitamin C before loading exercise.
Reported from published studies and product labelling — a record of what was used in research, not a recommendation. What is right for you is a conversation with a clinician.
Watch out for
- It is an incomplete protein — low in tryptophan — so it should not displace real protein in the diet
- Most trials are industry-funded, which is not disqualifying but is the reason to keep expectations small
Evidence base
established literature
Large human evidence base: several phase 3 or 4 trial reports, plus multiple meta-analyses or systematic reviews.
This letter measures how much human research exists, not whether it works for you — the tier above (Moderate) is the read on quality.
Research (12)
- Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysisInt J Dermatol · 2021
- Oral Collagen Supplementation: A Systematic Review of Dermatological ApplicationsJ Drugs Dermatol · 2019
- Collagen Supplementation for Joint Health: The Link between Composition and Scientific KnowledgeNutrients · 2023
- Exploring the Impact of Hydrolyzed Collagen Oral Supplementation on Skin Rejuvenation: A Systematic Review and Meta-AnalysisCureus · 2023
- Hydrolyzed Collagen-Sources and ApplicationsMolecules · 2019
- Effect of collagen supplementation on knee osteoarthritis: an updated systematic review and meta-analysis of randomised controlled trialsClin Exp Rheumatol · 2025
- Oral collagen supplementation for skin aging: A fad or the future?J Cosmet Dermatol · 2020
- Collagen supplementation in skin and orthopedic diseases: A review of the literatureHeliyon · 2023
- Oral Supplementation and Systemic Drugs for Skin Aging: A Narrative ReviewActas Dermosifiliogr · 2023
- The effect of oral collagen peptide supplementation on skin moisture and the dermal collagen network: evidence from an ex vivo model and randomized, placebo-controlled clinical trialsJ Cosmet Dermatol · 2015
- Collagen study advances for photoaging skinPhotodermatol Photoimmunol Photomed · 2024
- Collagen supplementation for skin health: A mechanistic systematic reviewJ Cosmet Dermatol · 2020
Turn Collagen peptides into a plan that's yours
The info above is free. Membership makes it personal, the Coach answers questions about your exact stack, the Stack tracks it for you, and the Verified Sources shows you how to vet what you buy.
- ✓ AI Coach, ask anything about your stack. It does the dosing math, flags interactions, and tells you what to do next.
- ✓ Personal Stack, save your protocol, track it across devices, log doses, get a heads-up before a vial runs out.
- ✓ Verified Sources, the vetted reference for checking quality and sourcing, members only.
Cancel anytime · or save with $59.99/yr · Coach + Stack included