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Hydrolysed collagen (cattle, fish)

Collagen

Oral hydrolysed collagen is generally well tolerated, and its best-supported use is easing knee osteoarthritis pain, where a meta-analysis of 11 trials found improvement, though the trials disagreed a lot. For skin, meta-analyses that pool all trials report better hydration and elasticity, but a 2025 analysis found the benefit vanished in trials not funded by supplement companies and in the highest-quality trials. Collagen creams cannot carry native collagen into the skin, and the hair and nail evidence is thin. People with fish or bovine allergy should check the source.

Updated
30 September 2026
Collagen powder being stirred into a glass of water
At a glance
Last reviewed 30 September 2026
Evidence
Moderate
Best for
Knee osteoarthritis pain
Typical form & use
Oral hydrolysed peptides (dose varies)
Onset
4+ weeks
Safety
Fish or bovine allergy: check the source. No interactions in our data.
Check with your medications →

What it's used for

Evidence is rated per use. The same ingredient can be strong for one thing and traditional for another.

UseEvidenceWhat the research shows
Knee osteoarthritis pain and functionModerateA 2025 meta-analysis of 11 randomised trials (870 people, 451 on collagen) found lower pain scores (mean difference -13.6, 95% CI -20.7 to -6.6) and better function (-6.5, -9.5 to -3.4) than placebo. The trials varied widely (I-squared 75% for function, 88% for pain), so the size of the benefit is uncertain. We did not open the individual trials and so cannot tell you which collagen type, dose or funder drove the result.5
Skin hydration and elasticity, oral peptidesLimitedPooled analyses are positive: 19 trials (1,125 people) found less wrinkling and better hydration and elasticity after about 90 days, and 26 trials (1,721 people) found better hydration. But a 2025 meta-analysis of 23 trials (1,474 people) found no effect on hydration, elasticity or wrinkles in trials not funded by pharmaceutical or supplement companies, and none in the high-quality trials, and concluded there is no clinical evidence to support collagen for skin ageing. A 2026 review rated most of 25 trials at high risk of bias. Mixed results across trials cap this at 2.1,2,3,4
Hair and nails, oralTraditionalA 2026 narrative review found only four hair studies and two nail studies, small, short and often multi-ingredient or industry-funded, with modest nail improvements reported. A dermatology review found that marketing claims for skin, nails and hair go beyond the published evidence. We found no trial of collagen on its own that we could cite for hair.6,9
Collagen creams and serums, topicalTraditionalNative collagen is a molecule of roughly 300 to 400 kDa, too large to cross the skin barrier, and a 2025 review says only very short peptides (under about 500 Da) penetrate easily. Collagen in a cream can moisturise the surface as a film, but it does not replace collagen in the dermis. We found no controlled trial showing topical collagen rebuilds skin collagen.7

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.

Duration studied for skin
About 90 days3
The 19-trial meta-analysis concluded benefit after 90 days of hydrolysed collagen; the pooled trials ran from weeks to months.
Trial length, knee osteoarthritis
Varied across 11 trials5
We did not read the individual trial doses, so we give no dose here. Follow the product label and ask a clinician about osteoarthritis.
Timing · No source we read gave advice on time of day.With food? · No source we read addressed whether to take it with food.How long to trial · Skin trials are judged at about 90 days, so give it 3 months at most before deciding. If no change by then, the evidence says you are not likely to see one.

How people take it

Powder or capsules (hydrolysed peptides)Varies by productThe form tested in the oral trials. Source (cattle, fish or pig) matters for allergy, and trial results were not clearly different by source.
Gummies and drinksVaries by productOften contain added sugar and other ingredients; one case report describes anaphylaxis from fish collagen in gummy tablets.
Cream or serumProduct-specificDoes not deliver collagen into the dermis (see topical row); any benefit is surface moisturising.

Safety

Who should avoid
  • Fish or shellfish allergy — marine collagen can trigger anaphylaxis in fish-allergic people
  • Bovine gelatin allergy — bovine collagen carries the same allergen
  • Pregnancy and breastfeeding — we found no safety data
  • Vegetarians and vegans — collagen is animal-derived
Known interactions
No interactions in our data. Absence of a flag is not clearance.

Questions people ask

What are the benefits of collagen?

The best evidence is for knee osteoarthritis pain, where a meta-analysis of 11 trials found improvement. For skin, pooled trials are positive but a 2025 analysis found no benefit in independently funded or high-quality trials. Hair and nail evidence is limited.

What are the benefits of hydrolysed collagen, and is it better than plain collagen?

Hydrolysed collagen is collagen broken into small peptides, and it is the form tested in nearly all the trials. The skin meta-analyses found better hydration and elasticity overall, but the benefit was not seen in trials without industry funding. We found no trial comparing it head to head with non-hydrolysed collagen.

Does collagen work for skin or hair?

For skin, it is unresolved: industry-funded trials are positive, independent trials are not. For hair, only a few small, often multi-ingredient studies exist. Creams cannot deliver native collagen into the skin because the molecule is too big.

What are the side effects of collagen?

A 2026 review of 25 trials found hydrolysed collagen generally well tolerated with few adverse events. The real risk is allergy: fish collagen has caused anaphylaxis in people with fish allergy, and bovine collagen is the major allergen in bovine gelatin allergy. Choose a source you do not react to.

Sources

  1. Systematic review Myung SK, Park Y. Effects of Collagen Supplements on Skin Aging: A Systematic Review and Meta-Analysis of Randomized Controlled Trials. Am J Med. 2025.
  2. Systematic review Pu SY, Huang YL, Pu CM, et al. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients. 2023.
  3. Systematic review de Miranda RB, Weimer P, Rossi RC. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. Int J Dermatol. 2021.
  4. Systematic review Bassila C, Bassila JC, Slim M. Efficacy and safety of hydrolyzed collagen supplementation on skin health outcomes: a systematic literature review of randomized controlled trials. Eur J Clin Nutr. 2026.
  5. Systematic review Simental-Mendía M, Ortega-Mata D, Acosta-Olivo CA, et al. Effect of collagen supplementation on knee osteoarthritis: an updated systematic review and meta-analysis of randomised controlled trials. Clin Exp Rheumatol. 2025.
  6. Review Biełach-Bazyluk A, et al. Dietary Collagen Supplementation as a Strategy for Skin Health: A Narrative Review of Clinical Effects on Skin, Hair, Nails, and Wound Healing. Nutrients. 2026.
  7. Review Egner P, et al. Collagen Hydrolysates from Animal By-Products in Topical Cosmetic Formulations. Int J Mol Sci. 2025.
  8. Case report Ueno R, Takaoka Y, Shimojo N, et al. A case of pediatric anaphylaxis caused by gummy tablets containing fish collagen. Asia Pac Allergy. 2020.
  9. Review Rustad AM, Nickles MA, McKenney JE, Bilimoria SN, Lio PA. Myths and media in oral collagen supplementation for the skin, nails, and hair: A review. J Cosmet Dermatol. 2022.
  10. Laboratory study Hori H, Hattori S, Inouye S, et al. Analysis of the major epitope of the alpha2 chain of bovine type I collagen in children with bovine gelatin allergy. J Allergy Clin Immunol. 2002.

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.

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Last reviewed 30 September 2026 · Next review March 2027 · How we rate evidence