BPC-157 vs TB-500: What the Studies Compared

BPC-157 and TB-500 are the two peptides most often compared by people reading about tissue repair research, and they are often described as if the evidence for them were the same. It is not. This guide sets out, study by study, what was actually tested for each: which animals, which tissues, which routes of administration and which outcomes. It then states plainly how little human evidence exists, why oral capsules are not what any of the studies used, and where both peptides sit on the WADA Prohibited List.

Two different molecules

BPC-157 is a 15-amino-acid peptide (molecular weight 1419, Staresinic et al., 2003) described as a partial sequence of a protein isolated from human gastric juice (Chang et al., 2011). Thymosin beta-4 is a naturally occurring 43-amino-acid peptide (Guarnera et al., 2010) and the major actin-sequestering molecule in mammalian cells (Philp and Kleinman, 2010). TB-500 is the commercial name for a synthetic peptide related to it; the WADA Prohibited List describes the category as "Thymosin-β4 and its derivatives e.g. TB-500". An analytical study of products sold online as TB500 found that their content "is not systematically consistent" with earlier descriptions (Delcourt et al., 2023).

What was studied for BPC-157

Four of the six studies below come from groups at the University of Zagreb, and all of the animal work in them is in rats, with beagle dogs added in one pharmacokinetic study.

• Transected Achilles tendon in rats (Staresinic et al., 2003): daily intraperitoneal injection; a functional index, load to failure and microscopy over 14 days, with treated animals scoring better than saline controls.
• Tendon detached from bone in rats (Krivic et al., 2006): tendon-to-bone healing, which did not occur spontaneously, was reported as improved with intraperitoneal BPC-157.
• Medial collateral ligament in rats (Cerovecki et al., 2010): intraperitoneal injection, a topical cream and the peptide in drinking water were all tested over 90 days.
• Crushed gastrocnemius muscle in rats (Novinscak et al., 2008): intraperitoneal and topical application.
• Cultured rat tendon fibroblasts (Chang et al., 2011): faster outgrowth from tendon explants and better survival under oxidative stress.
• Pharmacokinetics in rats and beagle dogs (He et al., 2022): after intravenous and intramuscular administration the half-life of the intact peptide was under 30 minutes; oral absorption was not measured.

A 2025 systematic review included 36 studies, 35 preclinical and one clinical, and found no clinical safety data (Vasireddi et al., 2025). A narrative review the same year called the human data "extremely limited" and said BPC-157 should be considered investigational (McGuire et al., 2025).

What was studied for thymosin beta-4

The thymosin beta-4 animal literature is older, broader in tissue type, mostly in mice, and concerns the full-length peptide rather than TB-500.

• Full-thickness skin wounds in diabetic and aged mice (Philp et al., 2003): thymosin beta-4 increased wound contracture and collagen deposition in diabetic mice and accelerated healing in aged animals.
• Alkali-burned corneas in mice (Sosne et al., 2002): topical treatment accelerated re-epithelialisation and reduced neutrophil infiltration and inflammatory transcripts.
• Coronary artery ligation in mice (Bock-Marquette et al., Nature 2004): thymosin beta-4 formed a complex with PINCH and integrin-linked kinase, activated Akt, enhanced early cardiomyocyte survival and improved cardiac function.

The two literatures cover different animals and tissues, so they are not two measurements of the same thing.

The one direct comparison

We found one published study that tested both peptides in the same model. In 2026 a group in Istanbul transected and repaired the Achilles tendon in 32 rats and assigned them to four groups of eight: control, BPC-157, TB-500, and both together, given intraperitoneally for four weeks (Biçer et al., 2026). Load to failure was higher in both treated groups than in controls but reached statistical significance only with TB-500. Histological scores were significantly better in the TB-500 group, while the BPC-157 group showed numerically better scores that did not reach significance. Combining the two "did not confer additional benefits compared to either agent alone". The authors call the study exploratory.

Human evidence: essentially absent

For BPC-157, reviewers count three small, uncontrolled pilot reports: a retrospective chart review of 17 patients given intra-articular injections for knee pain, with no standardised outcome measures (Lee and Padgett, 2021); injections around the bladder in 12 women with interstitial cystitis (Lee et al., 2024); and a two-participant report on intravenous infusion (Lee and Burgess, 2025). None is a randomised controlled trial.

Thymosin beta-4 trials used pharmaceutical-grade full-length peptide. A randomised, placebo-controlled phase 1 study gave intravenous thymosin beta-4 to 40 healthy volunteers in four cohorts, and adverse events were infrequent and mild or moderate (Ruff et al., 2010); a double-blind phase 2 study of topical thymosin beta-4 in 73 patients with venous stasis ulcers found a safety profile comparable to placebo and a suggestion that one concentration might accelerate healing (Guarnera et al., 2010). A PubMed search on 9 October 2026 found no clinical trial of TB-500 itself.

Capsules are not what was studied

Every human report above involved an injection, an infusion or a topical preparation. Of the animal studies listed, the only one that gave a peptide by mouth is the 2010 rat ligament study, which added drinking water alongside injection and cream. The one pharmacokinetic study measured intravenous and intramuscular administration only, so there are no published figures here for how much intact peptide a capsule delivers. Free Muscle's BPC-150 and TB-500 listings are capsules; both product pages say so and make no claim that a capsule matches the injected material in the studies.

WADA status

Both peptides are prohibited in sport at all times, under different sections of the 2026 WADA Prohibited List. BPC-157 is named in section S0, Non-approved substances, which covers substances with no current approval by any governmental health authority for human therapeutic use. TB-500 is named in section S2.3, Growth factors and growth factor modulators, as "Thymosin-β4 and its derivatives e.g. TB-500".

In the catalogue

Catalogue: BPC-157, TB-500 and Free Muscle's own BPC-150 capsules.

Research compounds sold by Free Muscle are supplied for laboratory research use only and are not for human consumption. They are not authorised as medicines by the MHRA, EMA or FDA, are not food supplements, and are sold only to adults aged 18 or over.

Frequently asked questions

What is the difference between BPC-157 and TB-500?

BPC-157 is a 15-amino-acid peptide described as part of a gastric juice protein, studied mainly in rat tendon, ligament and muscle models. TB-500 is a synthetic peptide related to thymosin beta-4, a 43-amino-acid peptide studied mainly in mouse skin, eye and heart models.

Has any study compared BPC-157 and TB-500 directly?

We found one. A 2026 rat Achilles tendon study with eight animals per group found that TB-500 reached statistical significance on load to failure and histology, BPC-157 showed numerically better scores without significance, and the combination added nothing over either alone. The authors call it exploratory.

Is there human evidence for BPC-157?

Three small uncontrolled pilot reports, all using injection or infusion, with 31 people in total. None is a randomised controlled trial, and a 2025 systematic review found no clinical safety data.

Is there human evidence for TB-500?

Not for TB-500 itself. Full-length thymosin beta-4 has been tested in regulated trials, for example a 40-volunteer intravenous phase 1 study and a 73-patient topical phase 2 study in venous ulcers.

Were capsules used in any of the studies?

No. The human reports used injection, infusion or topical application, and only one rat ligament study gave a peptide by mouth, in drinking water. None of the studies cited here tested an oral capsule.

Are BPC-157 and TB-500 banned in sport?

Yes, at all times. BPC-157 is named in section S0 of the 2026 WADA Prohibited List and TB-500 in section S2.3 as a thymosin beta-4 derivative.

Sources

1. Staresinic M et al. J Orthop Res 2003;21:976. PMID 14554208
2. Krivic A et al. J Orthop Res 2006;24:982. PMID 16583442
3. Cerovecki T et al. J Orthop Res 2010;28:1155. PMID 20225319
4. Novinscak T et al. Surg Today 2008;38:716. PMID 18668315
5. Chang CH et al. J Appl Physiol 2011;110:774. PMID 21030672
6. He L et al. Front Pharmacol 2022;13:1026182. PMID 36588717
7. Vasireddi N et al. HSS J 2025;21:485. PMID 40756949
8. McGuire FP et al. Curr Rev Musculoskelet Med 2025;18:611. PMID 40789979
9. Lee E, Padgett B. Altern Ther Health Med 2021;27(4):8. PMID 34324435
10. Lee E, Walker C, Ayadi B. Altern Ther Health Med 2024;30(10):12. PMID 39325560
11. Lee E, Burgess K. Altern Ther Health Med 2025;31(5):20. PMID 40131143
12. Philp D et al. Wound Repair Regen 2003;11:19. PMID 12581423
13. Sosne G et al. Exp Eye Res 2002;74:293. PMID 11950239
14. Bock-Marquette I et al. Nature 2004;432:466. PMID 15565145
15. Philp D, Kleinman HK. Ann N Y Acad Sci 2010;1194:81. PMID 20536453
16. Ruff D et al. Ann N Y Acad Sci 2010;1194:223. PMID 20536472
17. Guarnera G et al. Ann N Y Acad Sci 2010;1194:207. PMID 20536470
18. Biçer O et al. Jt Dis Relat Surg 2026;37:822. PMID 42542926
19. Delcourt V et al. Drug Test Anal 2023;15:458. PMID 36482504
20. World Anti-Doping Agency: The Prohibited List (2026).

All sources were read on 9 October 2026.