Hydrolysed Collagen Peptides (type I and III)

Hydrolysed collagen is the top-selling beauty supplement on iHerb, in Mercadona and Spanish pharmacy chains, marketed for skin firmness, wrinkle smoothing and dermal density. Evidence base is limited: Moc 2019 systematic review (11 RCTs, n=805) showed moderate improvement in skin hydration and elasticity over 8-12 weeks, but 9 of 11 trials were industry-funded, samples 30-100 participants, and design largely non-double-blind. The biological mechanism is weak: collagen in the GI tract is broken down to amino acids without direct dermal uptake. AAD for skin aging recommends daily SPF, topical retinoids and antioxidants (topical vitamin C); oral collagen is not listed as a proven option. If collagen was recommended as a substitute for sunscreen or topical retinoid, consider seeking a second opinion from a dermatologist.

Hydrolyzed collagen is collagen protein cut into peptides for easier absorption. It is sold to slow aging, extend life, and prevent age-related changes in skin, hair, and joints. After ingestion, hydrolyzed collagen is broken down in the gut to amino acids and small peptides; the body uses these amino acids the same way as those from any other protein source (meat, fish, eggs, dairy). Targeted delivery to skin or cartilage does not happen. Clinical studies are small, heterogeneous, and funded by supplement manufacturers; systematic reviews show that the effect on skin condition in healthy adults is either absent or clinically insignificant. The best collagen approach is a complete diet with adequate protein (1-1.5 g/kg body weight), vitamin C, and UV protection. If hydrolyzed collagen is being taken for anti-aging skin, consider seeking a second opinion.

Collagen is sold as a joint supplement – «cartilage nutrition». Garcia-Coronado 2019 meta-analysis (5 RCTs, 519 patients with knee osteoarthritis) showed a statistically significant but clinically minimal 17% WOMAC pain reduction over 3-6 months. All 5 trials were industry-funded. OARSI 2019 and NICE NG226 2022 do not recommend oral collagen for osteoarthritis. ESCEO 2014 and EULAR 2018 also do not include collagen in algorithms. First-line management for knee osteoarthritis remains non-pharmacological (weight loss at BMI>25, quadriceps-strengthening exercise), topical NSAIDs (diclofenac gel), paracetamol when NSAIDs contraindicated, and intra-articular steroid injection when effect is insufficient. If collagen was recommended as a substitute for exercise therapy or NSAIDs, consider seeking a second opinion from a rheumatologist.

Marketing attributes hair and nail strengthening to collagen. Evidence base is absent: no systematic reviews with clinical hair and nail endpoints published; EFSA has not approved any collagen health claim under Reg 432/2012 or subsequent assessments. For hair loss, AAD 2022 recommends diagnosing the cause (androgenetic alopecia, telogen effluvium, iron deficiency), topical 5% minoxidil and finasteride in male androgenetic alopecia. For nail brittleness without iron or zinc deficiency, oral supplements do not work – blood work is needed to exclude thyroid disease and anaemia. If collagen was recommended for hair loss without ferritin, TSH and scalp examination, consider seeking a second opinion.