Peptides for Healing Injuries: What Has Been Tested in People

The short answer

The peptides sold for healing are marketed for strained tendons, torn ligaments and sore joints. None is approved for those injuries, and none has been shown in a controlled human trial to speed recovery from them. The evidence behind the two best-known, BPC-157 and TB-500, is almost entirely from rats. A few peptides have been tested properly in people, but for skin ulcers and eye disease rather than sports injuries, and with mixed results. This guide separates the animal work from the human work, and where people were given a dose in a published study, it says what the dose was.

BPC-157: a large rat literature, almost no human data

BPC-157 is a 15-amino-acid fragment of a protein found in human gastric juice. In animals it has been studied for healing across tendon, muscle, gut and blood vessels, and one of its best-documented effects is promoting new blood-vessel growth alongside standard angiogenic growth factors.¹ Most of this work comes from one research group in Zagreb, which describes it as controlling rather than simply stimulating angiogenesis.²

The human record is two reports. A 2021 chart review of knee injections at a single clinic reached 16 patients by telephone; there was no control group and the outcome was recalled pain.³ A 2025 pilot gave intravenous BPC-157 to two adults who had used it before, 10 mg on one day and 20 mg the next, each infused over an hour; the infusions were tolerated and the tested markers of heart, liver, kidney and thyroid function and blood glucose did not change.⁴ Neither can show that BPC-157 heals anything in people, or reveal an uncommon harm.

In its July 2026 briefing to the Pharmacy Compounding Advisory Committee, FDA described BPC-157's nonclinical toxicology as limited and short, with no information ruling out immune reactions to it; the committee nonetheless voted to recommend allowing it in compounding.⁵ Our regulatory tracker follows what FDA does with that vote. BPC-157 is named on WADA's prohibited list under S0 for 2026 and 2027.⁶

TB-500 is not thymosin beta-4

TB-500 is a short synthetic fragment modelled on thymosin beta-4, a natural 43-amino-acid protein that helps cells move. The distinction matters because the human trials are of the full protein. The only published experiment with TB-500 as sold was in rats: after Achilles tendon repair, daily abdominal injections of TB-500 increased the load the tendon could bear, while BPC-157 alone did not reach significance.⁷

Thymosin beta-4 itself has been tested in people. Intravenous doses of 42, 140, 420 or 1,260 mg, given once and then daily for 14 days, were tolerated by 40 healthy volunteers without dose-limiting toxicity.⁸ Applied to skin, it was tested in venous leg ulcers⁹ and, in two phase 2 trials in stasis and pressure ulcers, sped healing by almost a month in patients who healed.¹⁰ As 0.1% eye drops it healed large neurotrophic corneal defects in a compassionate-use series,¹¹ reduced ocular discomfort by 35.1% against vehicle in a small dry-eye trial,¹² and in an 18-patient neurotrophic keratopathy trial healed 6 of 10 treated eyes against 1 of 8 on placebo at four weeks (p = 0.066).¹³ Two phase 3 dry-eye trials have been completed without producing an approval.^{14 15} None of this tested an injected fragment for a tendon.

Blends and stacks

BPC-157 and TB-500 are often sold together. No study has tested any combination in people. The rat tendon study above gave both together,⁷ and four patients in the knee chart review had received BPC-157 with thymosin beta-4, without a control group.³ Our guide to KLOW, GLOW and Wolverine covers the named blends.

Peptides that have had wound trials

LL-37, the one cathelicidin antimicrobial peptide humans make, has the clearest trial record, and it is mixed. In a first-in-human trial in 34 people with hard-to-heal venous leg ulcers, the two lower strengths, 0.5 and 1.6 mg/mL, applied twice weekly for four weeks, healed faster than placebo, while the highest did no better.¹⁶ In the larger phase IIb trial of 148 patients, at 0.5 or 1.6 mg/mL, it did not significantly improve healing overall.¹⁷ A small trial in mildly infected diabetic foot ulcers found better granulation tissue with LL-37 cream but no fall in bacterial colonisation.¹⁸

GHK-Cu has a large laboratory and animal record for wound repair, but in a small randomised trial after laser resurfacing it did not change redness, wrinkles or skin quality on objective measures.¹⁹ KPV eased colitis in mice and has never been tested in people, as FDA told its advisory committee in 2026.⁵

Antimicrobial peptides have also been tried for preventing wound and device infections. Omiganan, a gel tested at central venous catheter sites in 1,859 patients, missed its primary endpoint of local catheter-site infection.²⁰

What this means for an injury

For a tendon, ligament or muscle injury, the treatments with evidence are the ordinary ones a doctor or physiotherapist prescribes. The healing peptides are untested in people for these injuries, and a missing side-effect record is missing data, not a clean bill of health. Our evidence grades rate BPC-157 and TB-500 low for that reason, and our side-effects guide and legal status guide cover safety and the law, as of September 30, 2026.

Frequently asked questions

What is the best peptide for healing injuries?

None has been shown in a controlled human trial to speed recovery from tendon, ligament or muscle injuries, and none is approved for them. BPC-157 and TB-500 rest almost entirely on rat studies.

Does BPC-157 work in humans?

It is unknown. The human record is a telephone chart review of 16 knee patients with no control group and a safety pilot in two people. Neither can show that it heals anything.

Is TB-500 the same as thymosin beta-4?

No. TB-500 is a short synthetic fragment modelled on thymosin beta-4, a 43-amino-acid protein. The human trials, in skin ulcers and eye disease, used the full protein; TB-500 itself has one published rat study.

Is BPC-157 legal?

It is not FDA-approved. FDA's compounding advisory committee reviewed it in July 2026 and voted to recommend allowing compounding; our regulatory tracker follows FDA's decision. It is named on WADA's prohibited list under S0.

Are there peptides with real healing trials?

Yes, for wounds rather than sports injuries. Topical LL-37 sped healing of venous leg ulcers in a 34-person trial but missed its endpoint in a 148-person trial, and thymosin beta-4 eye drops have had phase 2 and phase 3 trials without an approval.

Related on Grey Peptides

• TB-500 complete guide
• KLOW vs GLOW vs Wolverine
• BPC-157 encyclopedia entry
• LL-37 encyclopedia entry
• Peptide side effects
• Regulatory tracker

Sources

1. Seiwerth, S. et al. (2018). BPC 157 and Standard Angiogenic Growth Factors. Gastrointestinal Tract Healing, Lessons from Tendon, Ligament, Muscle and Bone Healing. Current Pharmaceutical Design, 24(18), 1972-1989. PMID: 29998800
2. Sikiric, P. et al. (2025). BPC 157 Therapy: Targeting Angiogenesis and Nitric Oxide's Cytotoxic and Damaging Actions, but Maintaining, Promoting, or Recovering Their Essential Protective Functions. Pharmaceuticals, 18(10), 1450. PMID: 41155565
3. Lee, E. et al. (2021). Intra-articular injection of BPC 157 for multiple types of knee pain. Alternative Therapies in Health and Medicine, 27(4), 8–13. PMID: 34324435
4. Lee, E. et al. (2025). Safety of intravenous infusion of BPC157 in humans: a pilot study. Alternative Therapies in Health and Medicine, 31(5), 20–24. PMID: 40131143
5. US Food and Drug Administration (2026). Pharmacy Compounding Advisory Committee meeting, July 23-24, 2026: briefing documents for BPC-157, TB-500, epitalon and four other bulk drug substances. FDA
6. World Anti-Doping Agency. The 2026 Prohibited List, in force January 1, 2026: BPC-157 named under S0 (non-approved substances); the 2027 list, published August 2026, keeps it there. Read September 27, 2026. WADA
7. Biçer, O. et al. (2026). Effects of BPC-157 and TB-500 on Achilles tendon healing in rats: a histopathological and biomechanical study. Joint Diseases and Related Surgery, 37(3), 822–837. PMID: 42542926
8. Ruff, D. et al. (2010). A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Annals of the New York Academy of Sciences, 1194, 223–229. PMID: 20536472
9. Guarnera, G. et al. (2007). Thymosin beta-4 and venous ulcers: clinical remarks on a European prospective, randomized study on safety, tolerability, and enhancement on healing. Ann N Y Acad Sci, 1112, 407-12. PMID: 17495250
10. Treadwell, T. et al. (2012). The regenerative peptide thymosin β4 accelerates the rate of dermal healing in preclinical animal models and in patients. Ann N Y Acad Sci, 1270, 37-44. PMID: 23050815
11. Dunn, S. P. et al. (2010). Treatment of chronic nonhealing neurotrophic corneal epithelial defects with thymosin beta4. Ann N Y Acad Sci, 1194, 199-206. PMID: 20536469
12. Sosne, G. et al. (2015). Thymosin β4 significantly improves signs and symptoms of severe dry eye in a phase 2 randomized trial. Cornea, 34(5), 491-6. PMID: 25826322
13. Sosne, G. et al. (2022). 0.1% RGN-259 (Thymosin ß4) Ophthalmic Solution Promotes Healing and Improves Comfort in Neurotrophic Keratopathy Patients in a Randomized, Placebo-Controlled, Double-Masked Phase III Clinical Trial. Int J Mol Sci, 24(1). PMID: 36613994
14. ClinicalTrials.gov. NCT02974907: RGN-259 ophthalmic solution in dry eye (phase 3), completed. Record read September 27, 2026. ClinicalTrials.gov NCT02974907
15. ClinicalTrials.gov. NCT03937882: RGN-259 ophthalmic solution in dry eye (phase 3), completed. Record read September 27, 2026. ClinicalTrials.gov NCT03937882
16. Grönberg, A. et al. (2014). Treatment with LL-37 is safe and effective in enhancing healing of hard-to-heal venous leg ulcers: a randomized, placebo-controlled clinical trial. Wound Repair Regen, 22(5), 613-21. PMID: 25041740 · doi:10.1111/wrr.12211
17. Mahlapuu, M. et al. (2021). Evaluation of LL-37 in healing of hard-to-heal venous leg ulcers: A multicentric prospective randomized placebo-controlled clinical trial. Wound Repair Regen, 29(6), 938-950. PMID: 34687253 · doi:10.1111/wrr.12977
18. Miranda, E. et al. (2023). Efficacy of LL-37 cream in enhancing healing of diabetic foot ulcer: a randomized double-blind controlled trial. Arch Dermatol Res, 315(9), 2623-2633. PMID: 37480520 · doi:10.1007/s00403-023-02657-8
19. Miller, T. R. et al. (2006). Effects of topical copper tripeptide complex on CO2 laser-resurfaced skin. Arch Facial Plast Surg, 8(4), 252-9. PMID: 16847171 · doi:10.1001/archfaci.8.4.252
20. Cadence Pharmaceuticals. Topical omiganan 1% gel for preventing local catheter site infections in central venous catheterization (CLIRS, phase 3). ClinicalTrials.gov NCT00231153; completed July 2008; results read September 30, 2026. ClinicalTrials.gov NCT00231153

Educational information, not medical advice. Each dose in this guide names its source, an approved label or a published study. None is a recommendation for you. An unapproved compound has no established safe or effective human dose, and products sold for “research use only” are not made or tested for people. Talk to a doctor before acting on anything on this site, including before you start, stop or change any medicine or dose. An injury should be assessed by a clinician, and untested compounds are not a substitute for treatment.