Does protein help wound healing?

A little, and mainly in people who already have pressure ulcers. A 2024 Cochrane review found that supplements combining energy, protein and micronutrients may slightly raise the number of healed pressure ulcers, to 366 per 1,000 against 253 per 1,000 on a standard diet (RR 1.45, 95% CI 1.14 to 1.85), across 3 trials with 577 people. The evidence is rated low certainty. Protein supplements given to prevent new ulcers made little or no difference.

Unsettled. The Cochrane authors, pooling 33 randomized trials, concluded that the benefits of nutritional interventions for preventing and treating pressure ulcers are uncertain. The trials were small and used different mixtures, and the supplements that helped carried energy and micronutrients alongside protein. So the trials cannot say how much of the effect is the protein itself.

What the trials found

Healing pressure ulcers

The clearest signal is in mixed supplements for people who already have ulcers, the 366 against 253 per 1,000 above. Formulas that add arginine, zinc and antioxidants to a high-calorie, high-protein drink were pooled in a separate meta-analysis. At 8 weeks they shrank ulcer area by 15.7 percent more than control formulas (95% CI 1.5 to 29.9), and more people reached a 40 percent reduction in ulcer size (OR 1.72, 95% CI 1.04 to 2.84). The largest single trial, in 200 people with pressure ulcers in long-term and home care, found area fell 60.9 percent on the enriched formula and 45.2 percent on the control formula (adjusted difference 18.7 percent, 95% CI 5.7 to 31.8). The control in that trial had the same calories and protein, so the extra came from the arginine, zinc and antioxidants, not from more protein.

Arginine on its own, an amino acid, improved pressure ulcer healing in a meta-analysis of small trials (SMD -0.6, 95% CI -0.9 to -0.3) with high variation between them. In a trial in nursing home residents, a fortified collagen protein supplement gave about twice the rate of healing at 8 weeks on a standard ulcer score.

Preventing new ulcers

Across 4 trials with 4,264 people, protein supplements made little or no difference to how many developed a pressure ulcer, 21 per 1,000 against 28 (RR 0.75, 95% CI 0.49 to 1.14). One group is the exception. In older adults after a hip fracture, oral nutritional supplements high in protein were linked to fewer pressure ulcers across randomized trials (OR 0.54, 95% CI 0.33 to 0.88).

Leg ulcers and burns

A meta-analysis of 23 randomized trials in adults with chronic leg and foot wounds found nutritional supplements raised healing (RR 1.44, 95% CI 1.25 to 1.66). Those supplements varied and were not protein-specific. For burns, a review of 6 studies found only very weak evidence to justify high-protein diets, even though they are standard practice.

Who should be careful

Not for everyone. High-protein diets cause more stomach and bowel side effects. A review of 74 randomized trials found these events more common on high-protein diets, with no clear link to the dose. In the pressure ulcer trials themselves, Cochrane found supplements may not increase these side effects, and called that evidence very uncertain.

Kidney disease is the open question. Across 19 trials in adults without kidney disease, high-protein diets did not change serum creatinine (SMD 0.08, 95% CI -0.09 to 0.25). Those trials enrolled only adults without chronic kidney disease, so they say nothing about people who have it. If you have kidney disease, how much protein to eat while a wound heals is a decision for the person treating you.

What expert bodies say

The American College of Physicians recommends that clinicians use protein or amino acid supplements in patients with pressure ulcers to reduce wound size. It is a weak recommendation based on low-quality evidence. An earlier review funded by the US Agency for Healthcare Research and Quality rated the evidence that protein-containing supplements improve pressure ulcer healing as moderate, from 12 studies with 562 people. The 2024 Cochrane review, with more trials and stricter grading, is less confident than either.

How we searched

What would change this answer

• A trial that compares extra protein with extra calories alone in people with pressure ulcers. Today the benefit cannot be pinned on the protein.
• Trials of protein-rich food rather than supplement drinks. We found none in the Cochrane review.
• Larger trials in burns and in diabetic foot ulcers, where the evidence is weakest.
• Safety data on high-protein feeding in people with chronic kidney disease who have wounds.

Sources

1. ev-pwh-01 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 577
   Compared to standard diet, energy, protein and micronutrient supplements may slightly increase the number of healed pressure ulcers (energy, protein and micronutrients 366 per 1000, standard diet 253 per 1000; RR 1.45, 95% CI 1.14 to 1.85; 3 studies, 577 participants, low-certainty evidence).
   
   Who: people with existing pressure ulcers, 3 RCTs comparing energy, protein and micronutrient supplements with standard diet
   Effect: healed ulcers RR 1.45 (95% CI 1.14 to 1.85); 366 vs 253 per 1000; low-certainty evidence (GRADE)
   Certainty: The best synthesis; combined supplements, so protein alone is not isolated.
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
2. ev-pwh-02 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 4264
   Compared to standard diet, protein supplements may result in little to no difference in pressure ulcer incidence (protein 21 per 1000, standard diet 28 per 1000; RR 0.75, 95% CI 0.49 to 1.14; 4 studies, 4264 participants; low-certainty evidence).
   
   Who: people without pressure ulcers at baseline, 4 RCTs of protein supplements vs standard diet
   Effect: incident pressure ulcers RR 0.75 (95% CI 0.49 to 1.14); 21 vs 28 per 1000; low-certainty evidence
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
3. ev-pwh-03 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 7920
   The benefits of nutritional interventions with various compositions for pressure ulcer prevention and treatment are uncertain.
   
   Who: 33 RCTs with 7920 participants, with or without pressure ulcers
   Effect: overall benefit uncertain; no trial tested a protein-enriched diet (as opposed to supplements)
   Certainty: Axis 9: no study of special diets such as protein-enriched food; small, heterogeneous trials.
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
4. ev-pwh-04 · Meta-analysis or systematic review · Cochrane systematic review and meta-analysis of RCTs · n = 140
   Nutritional supplements may not increase gastrointestinal side effects, but the evidence is very uncertain.
   
   Who: participants of RCTs of nutritional supplements for pressure ulcers
   Effect: gastrointestinal side effects RR 0.70 (95% CI 0.06 to 7.96) for protein vs standard diet; very low-certainty evidence
   Cochrane Database Syst Rev, 2024 · checked 2026-10-07 · we read the abstract
5. ev-pwh-05 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 3 studies
   Compared with control interventions, formulas enriched with arginine, zinc and antioxidants resulted in significantly higher reduction in ulcer area (-15.7% [95%CI, -29.9, -1.5]; P=0.030; I2=58.6%) and a higher proportion of participants having a 40% or greater reduction in PU size (OR=1.72 [95%CI, 1.04, 2.84]; P=0.033; I2=0.0%) at 8 weeks.
   
   Who: patients with pressure ulcers, disease-specific oral or tube formula for at least 4 weeks vs control
   Effect: ulcer area -15.7% (95% CI -29.9 to -1.5) at 8 weeks; 40% or greater area reduction OR 1.72 (1.04 to 2.84); complete healing OR 1.72 (0.86 to 3.45), not significant
   Certainty: Industry-linked formula trials; the effect is on area, not on complete healing.
   J Nutr Health Aging, 2017 · checked 2026-10-07 · we read the abstract
6. ev-pwh-06 · Randomized controlled trial(s) · multicentre randomized controlled blinded trial · n = 200
   Supplementation with the enriched formula (n = 101) resulted in a greater reduction in PU area (mean reduction, 60.9% [95% CI, 54.3% to 67.5%]) than with the control formula (n = 99) (45.2% [CI, 38.4% to 52.0%]) (adjusted mean difference, 18.7% [CI, 5.7% to 31.8%]; P = 0.017).
   
   Who: 200 adult malnourished patients with stage II, III, and IV PUs in long-term and home care
   Effect: area reduction 60.9% vs 45.2%; adjusted MD 18.7% (95% CI 5.7 to 31.8); no difference in complete healing or infections
   Certainty: Control was isocaloric and isonitrogenous, so the extra effect is from arginine, zinc and antioxidants, not from more protein.
   Ann Intern Med, 2015 · checked 2026-10-07 · we read the abstract
7. ev-pwh-07 · Meta-analysis or systematic review · systematic review and meta-analysis of clinical trials · n = 196
   PIs were significantly improved with Arginine supplementation (SMD: -0.6; CI 95%: -0.9 to -0.3, I2 : 72.5%, p = .001).
   
   Who: patients with pressure injuries in clinical trials of arginine supplementation
   Effect: SMD -0.6 (95% CI -0.9 to -0.3; I2 72.5%); above 15 g/day SMD -2.8
   Certainty: Small trials, high heterogeneity; arginine is an amino acid, not dietary protein as such.
   Nurs Open, 2022 · checked 2026-10-07 · we read the abstract
8. ev-pwh-08 · Randomized controlled trial(s) · multicentre randomized 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, III or IV pressure ulcers
   Effect: better PUSH scores at 8 weeks (P < .05); about twice the healing rate
   Certainty: Small, 71 completers, unequal arms; Cochrane rates collagen evidence moderate certainty.
   Adv Skin Wound Care, 2006 · checked 2026-10-07 · we read the abstract
9. ev-pwh-09 · Meta-analysis or systematic review · systematic review and meta-analysis of RCTs · n = 23 studies
   Overall, nutritional supplementation was favorable (risk ratio [RR] = 1.44, 95% confidence interval [CI] = 1.25-1.66).
   
   Who: adults with chronic lower extremity wounds in randomized controlled trials
   Effect: healing RR 1.44 (95% CI 1.25 to 1.66); venous ulcers RR 1.44 (1.31 to 1.59); diabetic foot RR 1.17 (0.93 to 1.47), not significant
   Certainty: Mixed supplements, systemic and topical; not protein-specific.
   Int J Low Extrem Wounds, 2016 · checked 2026-10-07 · we read the abstract
10. ev-pwh-10 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized trials · n = 1522
    The overall meta-analysis demonstrated that ONS was associated with significantly elevated albumin levels (weighted mean difference (WMD) 1.24 (95% confidence interval (CI) 0.95 to 1.53)), as well as a significant risk reduction in infective complications (odds ratio (OR) 0.54 (95% CI 0.39 to 0.76)), pressure ulcers (OR 0.54 (95% CI 0.33 to 0.88)), and total complications (OR 0.57 (95% CI 0.42 to 0.79)).
    
    Who: older patients with hip fracture, aged 50 years or more, 18 randomized trials
    Effect: pressure ulcers OR 0.54 (95% CI 0.33 to 0.88); infective complications OR 0.54; length of stay -2.36 days
    Bone Joint J, 2023 · checked 2026-10-07 · we read the abstract
11. ev-pwh-11 · Observational data · systematic review of clinical trials (4 randomized), unblinded · n = 6 studies
    There is currently only very weak evidence to justify administering high protein diets to patients following burns.
    
    Who: burn patients receiving two or more levels of protein intake at or above 0.75 g/kg/day
    Effect: no reliable improvement in nitrogen balance or length of stay; some weight gain; no formal meta-analysis possible
    Certainty: Guidelines for burns advise high protein despite thin experimental evidence.
    Burns, 2021 · checked 2026-10-07 · we read the abstract
12. ev-pwh-12 · Observational data · systematic comparative effectiveness review of randomized and observational studies · n = 562
    In comparison with standard care, placebo, or sham interventions, moderate-strength evidence showed that air-fluidized beds (5 studies [n = 908]; high consistency), protein-containing nutritional supplements (12 studies [n = 562]; high consistency), radiant heat dressings (4 studies [n = 160]; moderate consistency), and electrical stimulation (9 studies [n = 397]; moderate consistency) improved healing of pressure ulcers.
    
    Who: adults with pressure ulcers; 12 studies of protein-containing nutritional supplements vs standard care or placebo
    Effect: improved healing, moderate strength of evidence, high consistency
    Certainty: Older search (to 2012); more favorable than Cochrane 2024, which graded certainty lower.
    Ann Intern Med, 2013 · checked 2026-10-07 · we read the abstract
13. ev-pwh-13 · Position of an expert body · clinical practice guideline · n = —
    RECOMMENDATION 1: ACP recommends that clinicians use protein or amino acid supplementation in patients with pressure ulcers to reduce wound size.
    
    Who: patients with pressure ulcers
    Effect: weak recommendation, low-quality evidence
    Certainty: Divergence: ACP recommends; Cochrane 2024 calls the benefit uncertain.
    Ann Intern Med, 2015 · checked 2026-10-07 · we read the abstract
14. ev-pwh-14 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials · n = 74 trials
    Adverse gastrointestinal events were more common with high-protein diets. Multivariable meta-regression analysis showed no significant dose response with higher protein intake.
    
    Who: adults in randomized trials comparing higher- and lower-protein diets
    Effect: adverse gastrointestinal events more frequent with high-protein diets; no dose response
    Certainty: Diet trials in general adults, not wound patients; harms poorly reported.
    Eur J Clin Nutr, 2012 · checked 2026-10-07 · we read the abstract
15. ev-pwh-15 · Meta-analysis or systematic review · systematic review and meta-analysis of randomized controlled trials with GRADE · n = 1044
    High-protein diets did not significantly change serum creatinine (19 trials; n = 1044; standardised mean difference 0.08, 95% confidence interval -0.09 to 0.25; I 2 = 20.8%), without consistent biochemical evidence suggestive of renal injury.
    
    Who: adults without chronic kidney disease in randomized trials of high-protein vs normal or low-protein diets
    Effect: serum creatinine SMD 0.08 (95% CI -0.09 to 0.25; 19 trials); no consistent biochemical sign of kidney injury
    Certainty: Older wound patients often have reduced kidney function; protein targets then need clinical supervision.
    Diabetes Obes Metab, 2026 · checked 2026-10-07 · we read the abstract