- BPC-157 is a synthetic 15-amino-acid peptide derived from a protein in human gastric juice. TB-500 is a synthetic fragment of thymosin beta-4, a naturally occurring 43-residue protein.
- The published research on BPC-157 is almost entirely preclinical and comes mostly from one group. Thymosin beta-4 has been in human trials; the fragment has not.
- Neither is a licensed medicine anywhere. Both are prohibited in sport under the WADA code, and the FDA has flagged BPC-157 as unsuitable for pharmacy compounding.
- They are studied together because they are thought to act on different parts of the same biology — one locally, one systemically — not because one is a 'version' of the other.
BPC-157 and TB-500 are sold together so often that many buyers assume they are a matched pair by design. They're not: they are two unrelated peptides with two different origins, two different evidence bases and — this is the part vendor pages skip — two different regulatory histories. This is a plain description of each, and of why they ended up in the same box.
BPC-157
What it is. BPC-157 — "Body Protection Compound 157" — is a synthetic peptide of fifteen amino acids (a pentadecapeptide) with the sequence Gly-Glu-Pro-Pro-Pro-Gly-Lys-Pro-Ala-Asp-Asp-Ala-Gly-Leu-Val. It's described as a fragment of a larger protein found in human gastric juice. Molecular mass is approximately 1,419 Da. It is stable in gastric acid, which is unusual for a peptide and is part of why it attracted attention.
The research. The published literature on BPC-157 is extensive in number and narrow in origin: the large majority of papers come from a single research group at the University of Zagreb, led by Predrag Sikirić, and describe experiments in rodents. Work from other laboratories exists but is limited. The models studied are varied — the gut, tendon, muscle, blood vessels, the nervous system — which is why the compound's reputation is so broad.
What does not exist is a completed, published, peer-reviewed human trial. A phase 1 study was registered; results have not been published in a journal. A reader weighing the evidence should weigh it as animal-model evidence from a small number of sources, and that is how we describe it.
Regulatory status. BPC-157 has no marketing authorisation anywhere. In September 2023 the US FDA placed it in Category 2 of its bulk drug substances review — substances that "may present significant safety risks" — which means it cannot lawfully be used in pharmacy compounding in the US. It is on the WADA Prohibited List under S0 (non-approved substances), so it is banned in competitive sport at all times. In the UK it may be bought and held for laboratory research; it may not be sold for human or veterinary use.
TB-500
What it is. Thymosin beta-4 (Tβ4) is a naturally occurring 43-amino-acid protein found in almost all human cells, where its main job is to bind actin — the protein that forms the cell's internal scaffold — and regulate how it assembles. "TB-500" is the name given to a synthetic peptide corresponding to the actin-binding region of Tβ4, residues 17–23 (Leu-Lys-Lys-Thr-Glu-Thr-Gln), although in the research-supply market the name is also used loosely for full-length Tβ4. A certificate of analysis should make clear which is in the vial by its stated mass: the seven-residue fragment is around 890 Da; full-length Tβ4 is around 4,963 Da.
The research. Full-length thymosin beta-4 has a substantial literature, including human clinical trials — sponsored mainly by RegeneRx Biopharmaceuticals — in wound healing, dry eye and cardiac indications. Those trials did not lead to a licensed product. The short TB-500 fragment has a much thinner literature, mostly cell and animal work exploring whether the actin-binding sequence carries the parent protein's activity.
Regulatory status. No marketing authorisation anywhere. Thymosin beta-4 and its fragments are prohibited under the WADA code. Same UK position as BPC-157: research use only.
Why they are studied together
The rationale in the research literature — and it is a rationale, not a result — is that the two compounds are thought to act on different parts of the same picture:
- BPC-157 has been studied mainly for local effects at a site of damage in animal models.
- Thymosin beta-4, through its role in actin dynamics, has been studied for systemic effects on cell migration and tissue organisation.
Whether those two mechanisms are complementary in any given experiment is a question for that experiment. What can be said with confidence is that they are different molecules doing different things, which is a better reason to study them side by side than the fact that they share a nickname.
We'd add one caution. The pairing is popular enough that it has acquired an informal name and a certain mythology online. None of that is evidence. The honest summary of the science is: promising animal data for one, older human data for the parent protein of the other, and no licensed use for either.
What matters for research supply
The questions are the same as for any peptide, with one addition:
- Which TB-500? The certificate should state a mass that tells you whether the vial contains the 7-residue fragment or full-length Tβ4. How to read that field.
- Purity per component. In a two-peptide product, the certificate should report each peptide separately, not one blended figure.
- Batch traceability — certificate, carton and the batch lookup should agree.
- Cold chain — 2–8°C, do not freeze, keep in the carton.
How Biovanta supplies them
BPC-157 + TB-500, 40 mg — 20 mg of each, in a single pre-filled pen with sterile needles and prep swabs. Manufactured in Switzerland, held refrigerated in the UK, dispatched next working day. Manufacturer HPLC-MS certificate available before you order, and an independent Janoshik report per batch as each completes — the testing page shows which batches have one and lets you verify it by key. Supplied strictly for in-vitro laboratory research.
Sources
- Sikirić P, et al. (2018). Brain-gut axis and pentadecapeptide BPC 157: theoretical and practical implications. Current Neuropharmacology 16(1), 61–72.
- Goldstein AL, Hannappel E, Kleinman HK (2005). Thymosin β4: actin-sequestering protein moonlights to repair injured tissues. Trends in Molecular Medicine 11(9), 421–429.
- US FDA — Pharmacy Compounding Advisory Committee, September 2023: BPC-157 (bulk drug substances nominated for use in compounding)
- World Anti-Doping Agency — The Prohibited List
Questions this article answers
Is BPC-157 legal in the UK?
It is lawful to buy, sell and hold for laboratory research. It is not a licensed medicine and cannot be sold or advertised for human or veterinary use. It is prohibited in sport under the WADA code.
Are there human clinical trials of BPC-157?
No completed, peer-reviewed human trial has been published. The evidence base is preclinical — mostly rodent studies — and comes largely from one research group. A phase 1 study was registered but results have not appeared in a journal.
Is TB-500 the same as thymosin beta-4?
Not exactly. Thymosin beta-4 is a 43-residue natural protein. TB-500 properly refers to a synthetic 7-residue fragment of it (residues 17–23), though vendors sometimes use the name for the full-length protein. The mass on the certificate of analysis tells you which one is in the vial.
Why did the FDA restrict BPC-157?
In September 2023 the FDA placed BPC-157 in Category 2 of its bulk drug substances review, citing insufficient safety information and potential risks, which bars its use in US pharmacy compounding. This does not affect its status as a research compound in the UK.
Want the certificate for a real batch?
Name a compound and we'll send the manufacturer's HPLC-MS certificate for the batch you would receive — before you order, no account needed.