Peptides for tendon recovery, ranked by human evidence

Tendons heal slowly, which is why tendon injuries drive so many peptide searches. The honest headline for this list is uncomfortable: none of these five peptides has a published human trial for tendon healing. Every one of them is graded animal only for tendon use: BPC-157, TB-500, and GHK-Cu on our tendon injury page, and PEG-MGF and IGF-1 LR3 in their own records, which list no tendon study at all.

So why rank them at all? Because people are comparing them anyway, often on the strength of marketing. A ranking anchored to our evidence grades makes the gaps explicit instead of hiding them.

How we ranked

We ordered the peptides by three criteria, in this order:

1. Human evidence for tendon injury. Every peptide scores zero here, so this criterion produces a tie.
2. How close the animal evidence is to tendon. A rat Achilles tendon study ranks above a skin wound study, which ranks above a muscle cell study.
3. Regulatory path. A peptide with a pending bulks list recommendation ranks above one that cannot lawfully be compounded at all.

Evidence grades and statuses come from each peptide's record, verified September 22, 2026.

1. BPC-157

• GradeEvidence: Animal only
• StatusRegulatory: Under review
• WADAWADA: Prohibited

BPC-157 is the only peptide on this list with tendon-specific studies. In a 2011 rat study, it accelerated healing of a transected Achilles tendon and increased the outgrowth, survival, and migration of tendon fibroblasts. [1] A 2019 review of musculoskeletal healing found consistent positive rodent results but human evidence limited to unpublished pilot work, and said human trials are needed. [2] Most of the animal research comes from a small number of laboratories, which limits independent replication. [2]

In July 2026 the Pharmacy Compounding Advisory Committee recommended BPC-157 for the 503A bulks list, but FDA has not published a final rule. [11] Track it on the BPC-157 regulatory timeline. Because it is not on the 503A bulks list, there is no lawful compounded price to report, and advertised clinic prices are not a comparable price; see the BPC-157 cost page. It is prohibited for tested athletes. [13]

2. TB-500

• GradeEvidence: Animal only
• StatusRegulatory: Under review
• WADAWADA: Prohibited

TB-500 is sold as a synthetic version or fragment of thymosin beta-4. In a rat full-thickness skin wound model, thymosin beta-4 increased reepithelialization by 42% at day 4 and up to 61% at day 7. [3] That is wound healing, not tendon healing, which is why it ranks below BPC-157.

The only randomized human trial involves 0.1% thymosin beta-4 eye drops for dry eye in 72 adults, and neither primary endpoint beat placebo. [4] It is a different product, route, and condition from injected TB-500. PCAC recommended TB-500 for the bulks list in July 2026, with no final rule yet. [11] WADA names thymosin beta-4 and TB-500 among prohibited peptide hormones and growth factors. [13]

For a direct side-by-side, see BPC-157 vs TB-500.

3. GHK-Cu

• GradeEvidence: Human observational overall, animal only for tendon
• StatusRegulatory: Removed from Category 2, not listed
• WADAWADA: Unclear

GHK-Cu is a copper-binding tripeptide found in human plasma. Its human data are small controlled studies of topical creams on aging skin, summarized in reviews largely written by the peptide's discoverer. [6] For tissue repair, the evidence is animal and cell work showing effects on collagen synthesis and wound healing. [5] There is no human trial of injected GHK-Cu for any condition.

FDA's April 2026 update moved injectable GHK-Cu from Category 2 to the withdrawn-nominations list, which is not the same as being on the bulks list. [10] Compare it with TB-500 in TB-500 vs GHK-Cu.

4. PEG-MGF

• GradeEvidence: Animal only
• StatusRegulatory: Removed from Category 2, no active nomination
• WADAWADA: Prohibited

PEG-MGF is a pegylated copy of part of mechano growth factor, a splice variant of IGF-1 made in muscle. The evidence is in vitro myoblast work and rodent muscle studies. [7] We found no tendon study, and no study has given PEG-MGF to a person. With no active nomination and no listing, a 503A pharmacy has no lawful basis to compound it. [10] [12]

5. IGF-1 LR3

• GradeEvidence: Animal only
• StatusRegulatory: Never listed
• WADAWADA: Prohibited

IGF-1 LR3 is an engineered IGF-1 analog from the early 1990s. In catabolic rats it was more anabolic than IGF-1 itself on body weight and nitrogen retention. [8] There is no tendon study and no human study. It has never been placed on the bulks list, so it cannot lawfully be compounded, and WADA prohibits IGF-1 and its analogues. [12] [13]

What actually has human evidence for tendons

Loading. In a 1998 study, 15 recreational athletes with chronic Achilles tendinosis did 12 weeks of heavy-load eccentric calf training, and all returned to their pre-injury level with full running. [9] It was small and not randomized, but it is human data on the actual condition, which is more than any peptide on this list can claim. Progressive loading, activity modification, and physical therapy are the standard of care described on our tendon injury page.

The takeaway

If you see a peptide marketed as "proven" for tendon repair, ask for the human trial. For these five, there is not one yet. We will re-rank this list when a published human study changes a grade.