BPC-157 vs TB-500

BPC-157 and TB-500 differ in parent molecule, size and studied target. BPC-157 is a 15-residue fragment of a stomach protein with no single identified receptor. TB-500 is the acetylated 7-residue actin-binding site of thymosin beta-4. Evidence for both comes mainly from animals, and one rat study has compared them head to head. ^[9][10][5]

The parent molecules explain most of the gap. A University of Zagreb group described BPC in 1993 as a gastric juice peptide of relative molecular mass 40,000, and BPC 157 as a 15-amino-acid fragment "thought to be essential for its activity". ^[11] Thymosin beta-4 is a 43-amino-acid protein found in essentially all cells, where it is the main molecule that binds and holds free actin. ^[12]

TB-500 is a short synthetic fragment of that protein. A Belgian anti-doping lab identified the N-terminal acetylated 17 to 23 fragment, Ac-LKKTETQ, in a product sold as TB-500 in 2012. ^[2] The NCBI reference record for human thymosin beta-4 lists 44 residues because it counts the starting methionine, which puts LKKTETQ at positions 18 to 24 of that record. ^[13] Both numbering schemes describe the same seven residues.

One more detail matters for anyone reading TB-500 studies. A 2024 Korean doping-control group wrote that the biological effects of TB-500 itself "have not been documented", and most activity data come from the unacetylated LKKTETQ or the full protein. ^[14] The two compounds sit in our recovery research peptides range.

BPC-157 is about 1.6 times heavier than TB-500, has twice as many residues, and has a larger rodent literature. The table puts the two compounds on the same dimensions.

Identifiers come from PubChem, which we checked on 29 September 2026. ^[1][4] The half-life is from a 2022 study in rats and beagle dogs. ^[15] Scheduling comes from the June 2026 Poisons Standard, ^[3] and sport status from the WADA 2026 List. ^[8] Prices are in Australian dollars.

BPC-157 has no single identified receptor in published work. Studies describe activity on several signalling pathways, mostly in rat cells and rodents, and a 2019 review from Loughborough University said the precise mechanisms still need to be understood. ^[9]

Three pathways recur, and a Taiwanese group at Chang Gung University produced much of the cell work behind them:

1. FAK-paxillin. In rat Achilles tendon fibroblasts, a 2011 study reported faster outgrowth from tendon explants, better cell survival under hydrogen peroxide stress and more cell migration, linked to activation of the FAK-paxillin pathway. ^[16]
2. Growth hormone receptor. The same group reported in 2014 that the growth hormone receptor was one of the most up-regulated genes in those fibroblasts, with downstream JAK2 activation. ^[17]
3. VEGFR2-Akt-eNOS. A 2017 study reported more new vessels in chick embryo membranes and higher VEGFR2 expression in human vascular endothelial cells and in rats with hind limb ischaemia. ^[18]

BPC-157 also clears fast. The 2022 pharmacokinetic study measured a half-life under 30 minutes in rats and dogs, with the peptide broken into small fragments and excreted in urine and bile. ^[15] The full mechanism literature, including the nitric oxide work, is in our BPC-157 explainer.

TB-500 is studied as the actin-binding site of thymosin beta-4. A Hong Kong Jockey Club lab described the 17 to 23 segment as the active site within the protein responsible for actin binding and cell migration. ^[10] The full protein is the main actin-sequestering molecule in cells. ^[12]

The fragment carries some activity of its parent in animal models. A 2003 NIH study reported that a seven-amino-acid synthetic peptide, LKKTETQ, promoted dermal wound repair in aged mice to a degree comparable with full thymosin beta-4. ^[19] That peptide lacked the acetyl group that TB-500 carries.

The 2024 Korean study is the most direct look at TB-500 itself. In rat urine, the main metabolite was Ac-LK, highest in the first 6 hours, and a second metabolite, Ac-LKK, was detectable for up to 72 hours. In fibroblast tests, neither TB-500 nor its metabolites showed cytotoxicity, and only the metabolite Ac-LKKTE showed a significant effect in the wound-closure assay. The authors suggest earlier activity attributed to TB-500 may come from that metabolite. ^[14]

Anti-doping chemists have also mapped how TB-500 breaks down. A 2016 study found high metabolic activity when TB-500 was incubated with human kidney microsomes and liver S9 fraction, with cleavage of all peptide bonds. ^[20] No published study in our source set reports a plasma half-life for the fragment. More detail on the fragment and its parent protein is in our TB-500 explainer.

One controlled study has compared BPC-157 and TB-500 directly, and it used rats. We searched PubMed on 29 September 2026 for records naming both compounds and found 12: that rat study, one retrospective human report, one analytical method paper and nine reviews. ^[21]

The rat study came from an Istanbul orthopaedic group and was published in 2026. Thirty-two male Sprague-Dawley rats had an Achilles tendon cut and repaired, then were randomised into four groups of eight: control, BPC-157, TB-500 and both combined. Tendons were tested after four weeks. ^[5]

The authors call it an exploratory study. They suggest the missing additive effect may reflect shared downstream pathways and say that idea needs testing. ^[5] Eight rats per group, one lab and a four-week window make it a starting point. The two peptides were also given at different amounts, so the comparison is unmatched by mass.

The only human record naming both is a 2021 retrospective knee report from a Florida clinic. Staff reached 16 of 17 past patients by phone and used no measurement tools. The report pools patients given BPC-157 alone with those given BPC-157 plus thymosin beta-4, which it calls TB4, and 14 of 16 reported relief. ^[22] With no control group and pooled products, it cannot separate the two compounds.

Researchers have studied BPC-157 and TB-500 together in one controlled experiment, the 2026 rat Achilles study, where the combination showed no added benefit over either peptide alone. ^[5] No human study has tested the pair with a control group.

Wolverine Stack is the name sellers use for a single vial holding both compounds. Our Wolverine Stack is a 10mg lyophilised vial for A$85, and it has its own batch certificate. KLOW, an 80mg vial for A$168, holds BPC-157 and TB-500 with GHK-Cu and KPV.

A combined vial changes what a certificate has to show. Each compound has its own mass, 1419.5 and 889.0 g/mol, so the identity section should report a result for each one. ^[1][4]

The three human pilots of BPC-157 reported no adverse events, and a 2025 review notes that large, rigorous trials are lacking. ^[6] No study reports human adverse events for the TB-500 fragment. The only human trial data in this area come from full-length thymosin beta-4.

For BPC-157, the published record shows:

• Intravenous pilot (2025). Two adults aged 58 and 68 showed no measurable change in tested markers of the heart, liver, kidneys, thyroid or blood glucose, and neither reported a side effect. ^[23]
• Interstitial cystitis pilot (2024). Twelve women aged 39 to 76 received BPC-157 into the bladder wall during one cystoscopy. No one dropped out and no adverse events were reported. ^[24]
• Animal toxicology (2020). Across mice, rats, rabbits and dogs, creatinine fell in dogs at the highest level tested and returned to normal 2 weeks after exposure stopped. Local irritation was mild, and the study reported no genetic or embryo-fetal toxicity. ^[25]

For TB-500 and its parent protein:

• TB-500 fragment (2024). Fibroblast tests found no cytotoxicity from TB-500 or its metabolites. ^[14]
• Full thymosin beta-4, intravenous phase 1 (2010). Four cohorts of 10 healthy volunteers reported adverse events that were infrequent and mild or moderate, with no serious adverse events. ^[7]
• Full thymosin beta-4 eye drops, phase 2 (2015). In 72 adults with dry eye, no adverse events were observed. ^[26]
• Full thymosin beta-4 topical gel, phase 2 (2010). In 73 patients with venous ulcers, the authors judged the adverse event profile acceptable and comparable to placebo. ^[27]

Those thymosin beta-4 trials used a different, much larger molecule by different routes. They describe the parent protein.

Two sources cover both compounds. The TGA names BPC-157 and TB-500 among unapproved peptide products it has not evaluated. Reports it received for that group include severe allergic reactions needing adrenaline and hospital care, and systemic inflammatory response syndrome, without attribution to one compound. ^[28] A 2026 review in Missouri Medicine lists contamination, manufacturing impurities, pathological angiogenesis and carcinogenesis among potential risks of unapproved peptides including both. The review presents them as potential risks. ^[29]

BPC-157 and TB-500 have the same Australian status: each has a named Schedule 4 entry (prescription only) and each is listed in Appendix D clause 5, which makes possession without authority an offence. BPC-157 is item 5 and TB-500 item 35 in that table, in the Poisons Standard instrument that commenced on 1 June 2026. ^[3]

Full thymosin beta-4 carries a separate Schedule 4 entry and is item 36 in the same Appendix D table. ^[3] No product containing either compound is registered as a medicine, and the TGA lists both among unapproved peptide products. ^[28] Our guide to Australian peptide law and the Poisons Standard explains what Schedule 4 and Appendix D mean.

Sport rules place them in different classes with the same effect. The WADA 2026 List, effective 1 January 2026, names BPC-157 in class S0, non-approved substances. Its index places TB-500 and thymosin-beta-4 in class S2, peptide hormones, growth factors, related substances and mimetics. Both classes are prohibited at all times. ^[8] WADA revises the List every year.

Peptides Collective sells both compounds for laboratory research use only. BPC-157 in 5mg vials costs A$81, and TB-500 in 10mg vials costs A$98. Stock ships from Western Australia with tracking.

Every batch is tested by an independent lab before it goes on sale, for purity by HPLC and identity by mass spectrometry. Each certificate is published under the batch number printed on the vial, and you can search the certificate of analysis library by that number. Each product page links the certificate for the batch currently on sale.

Identity is the result to check first for TB-500. A French horse-racing lab analysed products sold online as TB500 and TB1000 and found their content did not consistently match their descriptions. ^[30] The mass spectrometry result should match 1419.5 g/mol for BPC-157 and 889.0 g/mol for TB-500. ^[1][4] Our guide on how to read a peptide certificate of analysis walks through the HPLC trace and the mass spectrum.

BPC-157 and TB-500 are different molecules with different parents, masses and studied targets, and the one controlled comparison is a four-week rat study with eight animals per group. Neither has a controlled human trial of its own. In Australia both are Schedule 4 substances in Appendix D clause 5, and WADA prohibits both at all times. For a research vial, the batch certificate is the evidence that settles which compound is inside.