10–15 g/day (up to 20 g if the goal is to gain muscle mass or postoperative recovery), maintained for at least 8-12 weeks. Best combined with vitamin C, which is a cofactor of prolyl hydroxylase.
20 trials · ≈1,000 participants: small consistent improvement in skin hydration and elasticity. Wrinkles: 12 trials with a small favorable effect.
View the study (meta-analysis) →11 trials · 800 participants: small improvement in osteoarthritis symptoms (joint pain and function).
View the study (meta-analysis) →11 trials on strength · 8 on muscle mass: small improvement when combined with strength training, especially if dietary protein intake is low.
View the study (RCT) →4 trials · 115 participants: small improvement in recovery after exercise.
View the study (RCT) →*⏱ 3 min read
Collagens are the most abundant structural proteins in the human body, making up 30% of total protein mass, and are found in tendons, ligaments, cartilage, skin, blood vessels, muscles, intestinal tissue, and dentin; the body produces them continuously to maintain the structural integrity of tissues, but aging drives a progressive decline in protein synthesis and a reduced capacity to produce new collagen, which gives supplementation practical relevance.
Hydrolyzed collagen, also known as collagen peptides or collagen hydrolysate, is obtained by denaturing collagen into shorter chains of amino acids through thermal or enzymatic means; its most abundant amino acids are glycine, proline, and hydroxyproline, and it can be derived from bovine, porcine, avian, or marine sources, with marine sources being preferable in terms of safety because they do not transmit bovine or avian diseases.
For skin health, a randomized controlled trial of 69 women aged 35 to 55 found that 2.5 to 5 grams daily of hydrolyzed collagen for 8 weeks increased skin elasticity by 7% on average, with more pronounced effects in women over 50; and another trial of 64 women aged 40 to 60 showed that 1,000 mg daily of collagen with at least 15% tripeptides for 12 weeks improved hydration 7.23-fold at week 6 and wrinkles 10.5 times more than placebo.
For osteoarthritis, a systematic review of five randomized trials found that 2-10 grams daily of hydrolyzed collagen for 10 to 48 weeks reduced pain, stiffness, and functional limitations on the WOMAC index; for rheumatoid arthritis, surprisingly low doses of 20-100 micrograms of undenatured type II collagen reduce pain and the count of inflamed joints, possibly by inducing peripheral immune tolerance by acting as an antigen that suppresses the autoimmune response.
For bone health, 5 grams daily of hydrolyzed collagen for 12 months increased bone mineral density by 3% in the spine and 6.7% in the femoral neck in postmenopausal women, compared with a 1-1.3% decrease in the placebo group; and for joint pain in athletes, 10 grams daily for 24 weeks markedly reduced knee pain during activities such as walking, running, and changing direction compared with the control group.
Hydrolyzed marine collagen may have antihypertensive effects through inhibition of angiotensin-converting enzyme, a mechanism similar to that of some blood pressure drugs; and in a trial of 100 people with type 2 diabetes and hypertension, 6.5 grams of marine collagen twice a day for 3 months reduced fasting glucose by 19.7%, HbA1c by 6.8%, and diastolic blood pressure by 5.7%, clearly outperforming placebo on all metabolic parameters measured.
An important caveat: hydrolyzed collagen should not be used as a protein substitute because it lacks the essential amino acid tryptophan, which limits its nutritional value outside its specific effects on connective tissue; and although bone broth is promoted as a natural source of collagen, studies show that its concentrations of glycine, proline, and hydroxyproline are significantly lower and more variable than those of commercially prepared collagen supplements.
Information, not medical advice. Scientific evidence reflects the quality of the studies.