Does collagen help wound healing?

It depends on whether the collagen goes on the wound or into your mouth. Collagen dressings have the stronger case. A 2022 meta-analysis of 11 randomized trials in 961 people with chronic wounds found complete healing in 53% with a collagen dressing against 35% with standard care alone. Collagen you eat rests on much less. A 2024 Cochrane review found it probably shrinks pressure ulcers by 1.81 cm² more than placebo, and that estimate comes from one trial of 74 people.

Established. Collagen dressings added to standard care heal more chronic wounds. Across 11 randomized trials, mostly on diabetic foot and venous ulcers, the risk ratio for complete healing was 1.53 (95% CI 1.33 to 1.77). Many of the trials were small and tested commercial products, which is worth keeping in mind next to a number this tidy.

Unsettled. Collagen powders and drinks for wounds have a handful of small positive trials and no meta-analysis of their own. The trials are in pressure ulcers and major burns, mostly in hospitals and care homes, often with fortified products, and nobody has repeated them at scale.

What the trials found

Dressings on chronic wounds

The 2022 meta-analysis pooled 11 randomized trials in 961 people. Complete healing came to 259 of 485 on a collagen dressing and 164 of 476 on standard care. Seven of the trials reported side effects, and across 556 cases adverse events were not more common with collagen, with a risk ratio of 0.67 (95% CI 0.44 to 1.01). This is collagen applied to the wound, and it tells you nothing about collagen supplements.

Pressure ulcers, collagen by mouth

In the 2024 Cochrane review of nutrition for pressure ulcers, oral collagen was the one comparison the reviewers rated moderate certainty. Ulcers shrank by 1.81 cm² more than on placebo (95% CI 3.36 to 0.26 cm² smaller), in a single trial of 74 people. A 2026 systematic review of 18 randomized trials in 1231 people with pressure injuries found that nutrition products, collagen among them, appeared to help healing and prevent new injuries. Its authors add that the trials were small, varied and of moderate quality, and the review did not pool them.

The largest single collagen trial for pressure ulcers recruited 89 residents of 23 nursing homes with stage II to IV ulcers. A fortified collagen protein supplement taken three times a day gave about twice the rate of healing on the PUSH score at 8 weeks. The product was fortified, so collagen alone was not tested, the arms were uneven at 56 and 33, and 71 people finished.

Major burns

In a randomized trial of 66 patients with deep burns over 20 to 45% of the body, a drink giving 40 g of collagen a day brought complete healing to 26 days on average against 41.1 days on placebo. That was a single center and a high dose, given as part of hospital nutrition. A pilot trial of 31 men with burns over 20 to 30% of the body found wound healing 3.7 times more likely at any time point on a collagen supplement than on an isocaloric placebo (95% CI 1.434 to 9.519). It was men only, and the supplement carried 1000 calories.

Why small positive trials deserve caution here

A 2025 meta-analysis of 23 skin trials in 1474 people found collagen improved hydration, elasticity and wrinkles only in trials funded by industry. Trials without that funding, and the higher-quality ones, showed no effect. Those were skin aging trials, not wound trials. The wound trials above are small and mostly use commercial products, which is the setting where that bias showed up.

Who should be careful

Not for everyone. If you are prone to kidney stones, a large daily dose of gelatin or collagen deserves a second thought. In 10 healthy adults, 1.1 oz (30 g) of gelatin a day for 5 days raised urinary oxalate by 43% compared with whey protein. That was a tiny, short study, and the burn trial above used 40 g a day, more than that load.

Gelatin allergy is rare and can be severe. A case report describes a 20-year-old woman with gelatin-specific antibodies who went into anaphylaxis within 5 minutes of swallowing a gelatin capsule. How often this happens with collagen supplements is unknown.

For everyone else, the safety record in trials is short and shows few problems. A 2019 systematic review of 11 placebo-controlled trials with 805 people, at 2.5 to 10 g a day for 8 to 24 weeks, reported no adverse events. A 2026 review of 25 randomized trials of hydrolyzed collagen found few adverse events, though most of those trials were at high risk of bias and measured skin rather than wounds. With dressings, side effects were no more common than with standard care.

What expert bodies say

We found no expert body that recommends collagen supplements for wound healing. The European Union has no wound-healing claim for collagen in its register, and it did not authorize a claim that a branded collagen peptide mixture keeps skin healthy by raising elasticity and reducing wrinkles. The Cochrane review rated its oral collagen finding moderate certainty, the highest it gave any nutrition comparison for pressure ulcers, and still based it on one trial.

How we searched

What would change this answer

• A meta-analysis of oral collagen alone for wounds. Today the Cochrane estimate rests on one trial of 74 people, and a second good trial would move it more than anything else.
• Trials of plain collagen against a protein-matched placebo. Most positive trials used fortified products or extra calories, so the collagen share of the effect is unknown.
• Independent funding. In skin trials the benefit disappeared once industry-funded studies were set aside, and the wound trials have not been tested for the same bias.
• Larger burn trials in women as well as men, with doses people could take outside a hospital.

Sources

1. ev-cowh-01 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of 33 RCTs (7920 participants) · n = 74
   Compared to placebo, collagen supplements probably improve the mean change in pressure ulcer area (MD 1.81 cm² smaller, 95% CI 3.36 smaller to 0.26 smaller; 1 study, 74 participants, moderate-certainty evidence).
   
   Who: people with existing pressure ulcers, collagen supplement vs placebo
   Effect: mean change in ulcer area MD 1.81 cm2 smaller (95% CI 3.36 to 0.26 smaller); 1 study; moderate-certainty evidence
   Certainty: single trial behind the estimate; the only moderate-certainty finding in the review
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
2. ev-cowh-02 · Meta-analysis or systematic review · systematic review and meta-analysis of 11 RCTs with trial sequential analysis · n = 961
   Statistical analysis indicated that the wound healing rate in the collagen group is significantly higher than that in the control group (RR = 1.53; 95% CI, 1.33–1.77) (Figure 4A).
   
   Who: patients with chronic wounds (mostly diabetic foot and venous ulcers), collagen dressing plus standard care vs standard care
   Effect: complete healing 259/485 (53.4%) vs 164/476 (34.5%); RR 1.53 (95% CI 1.33 to 1.77); I2 28.2%
   Certainty: dressings applied to the wound, not collagen eaten; many trials industry products, small
   Frontiers in Surgery · checked 2026-10-07 · we read the fulltext
3. ev-cowh-03 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 556
   There was no difference in the risk of adverse events between the collagen group and SOC group (RR = 0.67; 95% CI, 0.44–1.01), as presented in Figure 7A.
   
   Who: patients with chronic wounds in 7 trials reporting adverse events
   Effect: adverse events RR 0.67 (95% CI 0.44 to 1.01)
   Certainty: dressing safety only; does not cover oral supplements
   Frontiers in Surgery · checked 2026-10-07 · we read the fulltext
4. ev-cowh-04 · Meta-analysis or systematic review · systematic review of 18 RCTs without meta-analysis · n = 1231
   Overall, nutritional interventions appeared to enhance wound healing and reduce the incidence of new PIs. However, the strength of evidence was limited by small sample sizes, variability in interventions, and moderate methodological quality.
   
   Who: people aged 38 to 83 with stage 2 to 4 pressure injuries
   Effect: positive effects on prevention and healing reported; no pooled effect size
   Certainty: collagen is one of several products; narrative synthesis
   Adv Skin Wound Care, 2026 · checked 2026-10-07 · we read the abstract
5. ev-cowh-05 · Meta-analysis or systematic review · systematic review of 11 RCTs without meta-analysis · n = 805
   Collagen supplementation is generally safe with no reported adverse events.
   
   Who: adults in RCTs of collagen hydrolysate 2.5 to 10 g a day for 8 to 24 weeks (pressure ulcers, xerosis, skin aging, cellulite) or collagen tripeptide
   Effect: no adverse events reported; benefit results called preliminary; no pooled estimate
   Certainty: few wound trials among the 11; authors call results preliminary
   J Drugs Dermatol, 2019 · checked 2026-10-07 · we read the abstract
6. ev-cowh-06 · Meta-analysis or systematic review · systematic literature review of RCTs, descriptive synthesis · n = 25 RCTs
   HC supplementation was generally well-tolerated, with a low incidence of adverse events.
   
   Who: adults in RCTs of oral hydrolyzed collagen, 13 to 236 participants per trial
   Effect: low incidence of adverse events; majority of trials high risk of bias
   Certainty: skin outcomes, not wounds; safety data short-term
   Eur J Clin Nutr, 2026 · checked 2026-10-07 · we read the abstract
7. ev-cowh-07 · Meta-analysis or systematic review · systematic review and meta-analysis of 23 RCTs · n = 1474
   However, in the subgroup meta-analysis by funding source, studies not receiving funding from pharmaceutical companies revealed no effect of collagen supplements for improving skin hydration, elasticity, and wrinkles, while those receiving funding from pharmaceutical companies did show significant effects.
   
   Who: adults in RCTs of collagen supplements for skin aging
   Effect: overall gains in hydration, elasticity, wrinkles; no effect in non-industry-funded or high-quality trials
   Certainty: skin aging, not wounds; relevant as a bias signal for small industry wound trials
   Am J Med, 2025 · checked 2026-10-07 · we read the abstract
8. ev-cowh-08 · Randomized controlled trial(s) · randomized, multicenter, placebo-controlled trial · n = 89
   By week 8, PUSH tool scores-a measurement of pressure ulcer healing-showed approximately twice the rate of pressure ulcer healing in the treatment group compared with the control group.
   
   Who: long-term-care residents with stage II to IV pressure ulcers, 23 facilities
   Effect: better PUSH scores at 8 weeks (P < .05); about twice the healing rate vs placebo; 71 completed
   Certainty: fortified product (not collagen alone); uneven arms 56 vs 33
   Adv Skin Wound Care, 2006 · checked 2026-10-07 · we read the abstract
9. ev-cowh-09 · Randomized controlled trial(s) · randomized clinical trial, three arms · n = 66
   The wound healing rate during the weeks post-burn (p = 0.006 and p = 0.01), and days of 95% (21.3 ± 6.8 and 22.9 ± 8.7 vs. 34.3 ± 14.8 days, p = 0.003 and p = 0.03) and complete (26 ± 7.7 and 27.4 ± 9.4 vs. 41.1 ± 16.6 days, p = 0.003 and p = 0.01) wound healing were significantly better with Collagen and Collagen.
   
   Who: patients with 20 to 45% deep partial or full-thickness burns, 4 weeks
   Effect: complete healing 26 ± 7.7 (collagen) and 27.4 ± 9.4 (collagen plus omega-3) vs 41.1 ± 16.6 days placebo; better scar scores
   Certainty: single center; high dose 40 g a day as part of hospital nutrition
   Clin Nutr, 2023 · checked 2026-10-07 · we read the abstract
10. ev-cowh-10 · Randomized controlled trial(s) · randomized double-blind controlled pilot trial · n = 31
    The Hazard ratio of wound healing was 3.7 times in collagen compared to control group (95% CI: 1.434-9.519, P=0.007).
    
    Who: men aged 18 to 60 with 20-30% total body surface area burn, 4 weeks
    Effect: hazard ratio of wound healing 3.7 (95% CI 1.434 to 9.519); hospital stay 9.4 vs 13.5 days (P = 0.063)
    Certainty: pilot, men only, 1000 calories supplement
    Burns, 2020 · checked 2026-10-07 · we read the abstract
11. ev-cowh-11 · Observational data · controlled crossover feeding study, randomization not stated · n = 10
    Urinary glycolate excretion was 5.3-fold higher on the gelatin diet compared to the whey diet and urinary oxalate excretion was 43% higher.
    
    Who: healthy subjects with no history of nephrolithiasis, two 5-day controlled diets with 30 g gelatin or whey, washout of at least 1 week
    Effect: urinary oxalate +43%, glycolate 5.3-fold vs whey
    Certainty: small, short; burn trials used 40 g a day, above this load
    Kidney International, 2006, Hydroxyproline ingestion and urinary oxalate and glycolate excretion · checked 2026-10-07 · we read the abstract
12. ev-cowh-12 · Laboratory or animal data · case report · n = 1
    Allergic reactions to gelatin are comparatively rare, but according to the past reports, the reactions were severe.
    
    Who: one 20-year-old woman with gelatin-specific IgE
    Effect: anaphylaxis within 5 minutes of a gelatin-containing capsule
    Certainty: single case; frequency of collagen supplement allergy unknown
    Arerugi, 2014 · checked 2026-10-07 · we read the abstract
13. ev-cowh-13 · Position of an expert body · EU Register on nutrition and health claims, claim POL-HC-8433, snapshot of 2026-09-21 · n = —
    POL-HC-8433 VeriSol®P Characteristic collagen peptide mixture (collagen hydrolysate) having a beneficial physiological effect on the maintenance of skin health, as indicated by an increased skin elasticity and a reduction of wrinkles volume, by contributing to a normal collagen and elastin synthesis. -/- Non-authorised
    
    Who: foods and supplements sold in the EU
    Effect: claim status: non-authorized
    Certainty: no wound-healing claim for collagen exists in the EU register
    EU Register on nutrition and health claims, claim POL-HC-8433, snapshot 2026-09-21 · checked 2026-10-07 · we read the section