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Ingredient guide

Collagen for women: what the trials in women found

Written by the Full Measure editorial team, which sells supplements. Approved for publication by the Full Measure owners. Updated .

Drafted with AI assistance from the sources listed below. How we write these

Quick answer

Collagen skin research is mostly in women: 21 of the 26 trials pooled in 2023 enrolled only women, most in their 30s to 60s. They used 2.5 to 10 g a day for 8 to 12 weeks and found modest gains in hydration and elasticity, but trials without company funding found none. No bone claim is made.1,2

Key facts

  • Skin trials enrolled women from their 20s to about 70.3
  • The one hair trial enrolled 114 women aged 20 to 50.4
  • A 2019 review says the body loses around 1 percent of its collagen a year after 40.5
  • Most skin trials used fish collagen.1

Skin

May support skin hydration and elasticity*1,2

Moderate evidence

A 2023 meta-analysis of 26 randomized trials (1,721 people, mostly women) found better skin hydration and elasticity with hydrolyzed collagen, usually 2.5 to 10 g a day for 8 to 12 weeks, though only one trial used bovine collagen like this product. A 2025 meta-analysis of 23 trials (1,474 people) found the benefit only in company-funded trials; trials without company funding, and higher-quality trials, showed no effect.

Amount studied: 2.5 to 10 g a day for 8 to 12 weeks

Skin research is mostly in women: in the 2023 analysis, 21 of the 26 trials enrolled only women, most in their 30s to 60s, and a 2021 analysis of 19 trials with 1,125 people was 95 percent women.1,3

A 2021 analysis of 19 trials with people aged 20 to 70 found better skin hydration, elasticity and wrinkle scores with hydrolyzed collagen than placebo, and pointed to about 90 days of use.3

The main 8-week trial behind the low doses gave women aged 35 to 55 either 2.5 g or 5 g of a branded peptide once a day, and both groups ended with more elastic skin than the placebo group.6

Women over 40 and 50

A 2019 review states that collagen loss starts in early adulthood and that after 40 the body loses around 1 percent of its collagen a year.5

Several skin trials enrolled women in their 50s and 60s, and the pooled results include them, with the same funding caveat as for younger women.1,2

Hair and nails

Hair research is thin. In one 24-week trial of 114 women, 1 g a day of a specialized low-molecular-weight fish collagen peptide increased hair diameter compared with placebo, and a 2026 review found most hair and nail studies short, mixed in design, often multi-ingredient and often industry funded.4,7

In one open-label study with no placebo group, 25 people with easily broken nails took 2.5 g of a branded collagen peptide daily for 24 weeks; nail growth rose 12 percent and broken nails fell 42 percent.8

Neither is enough for a claim: one study had no placebo group, and the other tested a specialized fish peptide at 1 g a day, far less than the 10 to 20 g in a typical collagen powder serving.4,8

Bones after menopause

No bone claim is made. The main trial gave 5 g a day of a branded collagen peptide for 12 months to 131 women past menopause who already had reduced bone density, and it has not been repeated by other groups. If you have been told your bone density is low, ask your doctor, and do not use collagen in place of the care you are offered.9

Pregnancy, nursing and kidney stones

The collagen trials reviewed here did not include pregnant or nursing women, so ask your doctor or midwife first.

If you have had kidney stones, ask before taking collagen daily: 30 g of gelatin raised urinary oxalate 43 percent compared with whey in a feeding study.10

What's in ours

What’s in ours

Questions people ask

Which collagen is best for women?

The trials do not single out a best type. Most skin trials used fish collagen, a few used pig or chicken, only one used bovine, and the main skin and nail studies used branded peptides.1,6,8

Can collagen replace protein for women who want to keep muscle?

No. Collagen lacks tryptophan and scores zero on the protein-quality scale, and whey raised muscle protein building more than collagen in head-to-head tests.11,12

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Sources

  1. Pu SY, Huang YL, Pu CM, Kang YN, Hoang KD, Chen KH, Chen C. Effects of Oral Collagen for Skin Anti-Aging: A Systematic Review and Meta-Analysis. Nutrients. 2023;15(9):2080. Opened 2026-10-01.
  2. 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;138(9):1264-1277. Opened 2026-10-01.
  3. 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;60(12):1449-1461. Opened 2026-10-07.
  4. Hwang S, Won J, Kim S, Kang W, Park M. Low-Molecular-Weight Collagen Peptide Supplementation Improves Cellulite Severity, Skin Elasticity, and Hair Shaft Diameter: A Clinical Study with Pharmacokinetic Evaluation. J Med Food. 2026;29(4):187-195. Opened 2026-10-07.
  5. León-López A, Morales-Peñaloza A, Martínez-Juárez VM, Vargas-Torres A, Zeugolis DI, Aguirre-Álvarez G. Hydrolyzed Collagen: Sources and Applications. Molecules. 2019;24(22):4031. Opened 2026-10-07.
  6. Proksch E, Segger D, Degwert J, Schunck M, Zague V, Oesser S. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacol Physiol. 2014;27(1):47-55. Opened 2026-10-07.
  7. Biełach-Bazyluk A, Jurga M, Flisiak I, Zbroch E. Dietary Collagen Supplementation as a Strategy for Skin Health: A Narrative Review of Clinical Effects on Skin, Hair, Nails, and Wound Healing. Nutrients. 2026;18(13):2141. Opened 2026-10-07.
  8. Hexsel D, Zague V, Schunck M, Siega C, Camozzato FO, Oesser S. Oral supplementation with specific bioactive collagen peptides improves nail growth and reduces symptoms of brittle nails. J Cosmet Dermatol. 2017;16(4):520-526. Opened 2026-10-07.
  9. König D, Oesser S, Scharla S, Zdzieblik D, Gollhofer A. Specific Collagen Peptides Improve Bone Mineral Density and Bone Markers in Postmenopausal Women-A Randomized Controlled Study. Nutrients. 2018;10(1):97. Opened 2026-10-01.
  10. Knight J, Jiang J, Assimos DG, Holmes RP. Hydroxyproline ingestion and urinary oxalate and glycolate excretion. Kidney Int. 2006;70(11):1929-1934. Opened 2026-10-07.
  11. Paul C, Leser S, Oesser S. Significant Amounts of Functional Collagen Peptides Can Be Incorporated in the Diet While Maintaining Indispensable Amino Acid Balance. Nutrients. 2019;11(5):1079. Opened 2026-10-07.
  12. Khatri M, Naughton RJ, Clifford T, Harper LD, Corr L. The effects of collagen peptide supplementation on body composition, collagen synthesis, and recovery from joint injury and exercise: a systematic review. Amino Acids. 2021;53(10):1493-1506. Opened 2026-10-01.

*These statements have not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

This page is information, not medical advice. Talk to your doctor or pharmacist about your own situation.