Collagen for Women: What the Trials in Women Measured

Most collagen trials recruited women, so the evidence for women is most of the evidence for collagen: the largest skin meta-analysis pooled 1,125 people aged 20 to 70, 95% of them women; the twelve-month bone trial enrolled 131 postmenopausal women on 5 g a day; the open-label nail study gave 2.5 g a day to 25 adults; and in a supplier part-funded trial, 77 premenopausal women gained more fat-free mass and grip strength on 15 g a day with resistance training.^{1, 2, 3, 4} This is the women's chapter of the Wellgard collagen guide; the men's trials are on collagen for men.

Who were the collagen trials done on?

Skin: women almost entirely, aged 20 to 70 in the pooled trials, most between 35 and 65.¹ Bone: postmenopausal women with low bone density only.² Nails: 25 adults with brittle nails, open-label.³ Muscle: mostly men, plus 77 premenopausal women in one training trial.⁴ Joints: men and women together, active adults aged 18 to 30 and adults with osteoarthritis.

The gaps: the only skin trial centred on women past 70, aged 60 to 93, was in fragile forearm skin; no bone trial before the menopause; no positive muscle result in women over 60; nothing under 20; and no prevention trial in young adults: "start at 25, before collagen declines" has not been tested.

What does collagen do for women's skin?

A 2023 meta-analysis of 26 randomised trials in 1,721 people found hydrolysed collagen improved hydration and elasticity, with no difference between collagen sources on elasticity.⁵ In 69 women aged 35 to 55, 2.5 g and 5 g a day for eight weeks both improved elasticity, and the older women held the gain four weeks after stopping.⁶ A 2026 trial of 119 women aged 35 to 55 compared 2.5 g and 10 g a day for twelve weeks against no supplement: elasticity and hydration improved on both doses and wrinkle number and length fell only on 10 g; it had no placebo arm and the peptides were supplied by their manufacturer.⁷ More on what the skin trials measured.

What we don't know: most skin trials were run or funded by peptide manufacturers, and a 2025 meta-analysis of 23 trials in 1,474 people found the improvement in hydration, elasticity and wrinkles across all the trials but not in the subgroup without company funding.⁸ Past 70 there is one trial: 56 women aged 60 to 93 with stage I dermatoporosis (fragile, thinning forearm skin) took 5 g a day, a 2.5% collagen serum or both for six months, and no measure changed; a gap for fragile skin at that age, not a result for healthy skin.⁹

Does collagen help women's bones?

131 postmenopausal women with age-related low bone density, average age 64, took 5 g of collagen peptides or placebo daily for twelve months: the spine T-score rose by 0.1 on collagen and fell by 0.03 on placebo, and the femoral neck rose by 0.09 against a fall of 0.01.² The authorised wording is protein's, "Protein contributes to the maintenance of normal bones", on a food that is a source of protein.¹⁶ What we don't know: whether the density change lowers fracture risk, and anything about women under 50. More on collagen for bones.

Does collagen help women's nails and hair?

Nails have been measured; hair alone only as one outcome among several, in two trials. In an open-label study of 25 people, 2.5 g a day for 24 weeks increased nail growth by 12% and cut broken nails by 42%, with no placebo group.³ No randomised trial has tested collagen on its own with hair growth or shedding as its main outcome; the shedding causes a GP can check and the zinc and biotin wordings are on collagen for hair and nails.

Does collagen help women build or keep muscle?

With training, yes: in a supplier part-funded trial, 77 premenopausal women trained three times a week for twelve weeks on 15 g a day or placebo; fat-free mass percentage, grip strength and fat loss all improved more on collagen.⁴ Across both sexes, a 2024 meta-analysis of 19 trials in 768 training adults found more fat-free mass on collagen than on training alone (effect size 0.48, moderate certainty) and a smaller gain in maximal strength (0.19).¹⁰ Body fat and weight are on collagen and weight.

Collagen lacks tryptophan and is low in leucine, so it adds to meat, fish, dairy, eggs, pulses or a whey shake rather than replacing them: in 22 women aged about 69, whey raised muscle protein synthesis over six days and collagen did not.¹¹ We found no trial of plain collagen with training in women over 60.

Does collagen help women's joints?

The joint trials recruited both sexes. A 2024 analysis of 35 randomised trials in 3,165 people with osteoarthritis found small to moderate reductions in pain (effect size -0.35, moderate certainty) and improvements in function (-0.31, high certainty), with no more adverse events or withdrawals than control.¹² In 180 active men and women aged 18 to 30, 5 g a day for twelve weeks cut exercise-related knee pain by 21.9 mm on a 100 mm scale against 15.6 mm on placebo.¹³ These are trial findings in a disease, not a claim any supplement may make; menopausal joint pain itself has not been tested.

How does the menopause change the picture?

The NHS lists among the changes of menopause and perimenopause "weakening bones (loss of bone density), which can lead to osteoporosis", "muscle aches and joint pains", "hair thinning or hair loss" and "skin changes, including dry and itchy skin": the outcomes the trials in women measured.¹⁴ No trial has tested collagen alone against menopause symptoms, and collagen is not an alternative to HRT. HRT, dry skin and gums are on collagen and the menopause; the decade-by-decade view is on what age to start collagen.

Can women take collagen in pregnancy or when breastfeeding?

No trial of collagen peptides has been run in pregnancy or breastfeeding, so nobody can call it proven safe; it is a food protein, the same as gelatine, and the NHS position applies: tell your midwife or GP what you take. The NHS says "do not take cod liver oil or supplements containing vitamin A" in pregnancy, so check any blend's label.¹⁵ Milk supply, stretch marks and postpartum shedding are on collagen in pregnancy and breastfeeding.

How much collagen should a woman take?

By outcome: 2.5 to 10 g a day for skin, with 2.5 g matching 5 g on elasticity and only 10 g reducing wrinkle count; 5 g a day for twelve months for bone; 2.5 g for nails; 15 g with training for fat-free mass; and 5 g for knee pain on exercise, all inside the literature's 2.5 to 15 g a day.^{2, 3, 4, 6, 7, 13} The full table is on how much collagen per day for a woman.

Frequently asked questions

What is the best collagen for women?

The trials in women used hydrolysed collagen peptides at 2.5 to 10 g a day for skin and 5 g over a year for bone, and the 2023 meta-analysis found no difference between sources on elasticity.⁵ The checks are the same as for anyone: grams of collagen per serving against the dose for your outcome, the declared source and origin, and a molecular weight stated as a range and the same every batch. Collagen itself has no authorised health claim in Great Britain, a statement about the register rather than a verdict on the trials; where a blend carries vitamin C, the authorised wording is vitamin C's: it "contributes to normal collagen formation for the normal function of skin".¹⁶

Should women take collagen?

The trials recruited healthy women from their twenties to their early seventies, postmenopausal women with low bone density and women who train. Ask a GP or pharmacist first if you are pregnant or breastfeeding, on a protein-restricted diet for kidney disease (collagen counts as protein), or have a fish allergy and are looking at marine collagen.

What does collagen do for women over 50?

The bone trial and the retained elasticity gain were measured in women over 50, the best-studied decade; the detail is on what age to start collagen.^{2, 6}

Collagen or whey for women?

Both, for different jobs: whey raised muscle protein synthesis in older women where collagen did not; collagen with training raised fat-free mass and grip strength in premenopausal women. More on collagen vs whey protein.^{4, 11}

Can women take collagen with HRT or the pill?

No interaction between collagen peptides and any medicine has been documented in trials or case reports, and the BNF interaction tables carry no collagen entry (checked 11 October 2026); collagen is a food protein, the same as gelatine. Tell your pharmacist what you take.

Sources

1. de Miranda RB, et al. Effects of hydrolyzed collagen supplementation on skin aging: a systematic review and meta-analysis. International Journal of Dermatology, 2021. PubMed 33742704.
2. König D, et al. Specific collagen peptides improve bone mineral density and bone markers in postmenopausal women: a randomized controlled study. Nutrients, 2018. PubMed 29337906.
3. Hexsel D, et al. Journal of Cosmetic Dermatology, 2017. PubMed 28786550.
4. Jendricke P, et al. Specific collagen peptides in combination with resistance training improve body composition and regional muscle strength in premenopausal women: a randomized controlled trial. Nutrients, 2019. Part supplier-funded. PubMed 31010031.
5. Pu SY, et al. Effects of oral collagen for skin anti-aging: a systematic review and meta-analysis. Nutrients, 2023. PubMed 37432180.
6. Proksch E, et al. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacology and Physiology, 2014. PubMed 23949208.
7. Paula-Vieira RHR, et al. Dermatology and Therapy, 2026. PubMed 41588262.
8. Myung SK, Park Y. Effects of collagen supplements on skin aging: a systematic review and meta-analysis of randomized controlled trials. American Journal of Medicine, 2025. PubMed 40324552.
9. Guadanhim LRS, et al. Efficacy and safety of topical or oral hydrolyzed collagen in women with dermatoporosis: a randomized, double-blind, factorial design study. Dermatology and Therapy, 2023. PubMed 36547800.
10. Bischof K, et al. Impact of collagen peptide supplementation in combination with long-term physical training on strength, musculotendinous remodeling, functional recovery, and body composition in healthy adults: a systematic review with meta-analysis. Sports Medicine, 2024. PubMed 39060741.
11. Oikawa SY, et al. Whey protein but not collagen peptides stimulate acute and longer-term muscle protein synthesis with and without resistance exercise in healthy older women: a randomized controlled trial. American Journal of Clinical Nutrition, 2020. PubMed 31919527.
12. Liang CW, et al. Efficacy and safety of collagen derivatives for osteoarthritis: a trial sequential meta-analysis. Osteoarthritis and Cartilage, 2024. PubMed 38218227.
13. Zdzieblik D, et al. Nutrients, 2021. PubMed 33562729.
14. NHS. Symptoms of menopause and perimenopause (page last reviewed 19 May 2026). nhs.uk.
15. NHS. Pregnancy vitamins and supplements (page last reviewed 3 June 2026). nhs.uk.
16. DHSC. Great Britain nutrition and health claims (NHC) register (last updated 19 May 2026). gov.uk.