BPC-157 and TB-500: how they differ
Two tissue-repair peptides that are often compared, and where they are not interchangeable.
They are the two peptides most often compared when talking about tissue repair, and they are usually mentioned together as if interchangeable. They are not: they are two different molecules, with different histories, and they share one important thing worth stating up front: almost all their literature is preclinical, in animals and cell culture, and neither is approved as a medicine in any country.
This page describes published literature. It is not medical information and does not describe a therapeutic use, and what is sold here are reagents for in vitro research.
The difference at a glance
| BPC-157 | TB-500 | |
|---|---|---|
| What it is | Pentadecapeptide (15 amino acids), fragment of the body protection compound, isolated from gastric juice | Ambiguous name: used for the full thymosin beta-4 (43 amino acids) and for its central actin-binding fragment |
| Evidence | Animal models (mainly rat) and cell culture | Animal models and cell culture |
| What was studied | Tendon, muscle and the digestive tract | Tissue repair: skin, cornea, heart, tendon |
| Regulatory status | Not approved in any country | Not approved in any country |
| What matters most when buying | HPLC purity of the lot | Identity (which molecule it is): purity is not enough |
BPC-157: a fragment from gastric juice
It is a chain of fifteen amino acids, a partial fragment of a larger protein, with an always-cited trait: it is stable in gastric juice for more than a day. Its literature is almost all in rats, centred on healing of tendon, muscle and the digestive tract, with proposed mechanisms —not demonstrated in humans— around the formation of new blood vessels.
TB-500: one name for two molecules
Here is the difference almost no one mentions and the one that matters most when buying: «TB-500» is used for two different things. For the full thymosin beta-4 (a 43-amino-acid protein present in almost every cell) and for its short central actin-binding fragment. Both circulate under the same commercial name, have very different molecular weights, and the product name does not tell you which is inside —nor does a purity percentage. Only a lot identity confirmation does.
The only study that compares them head to head
Most of what you read compares them by hearsay. There is one study that put them in the same experiment: in 2026, on the severed and repaired Achilles tendon of 32 rats, with four groups —control, BPC-157, TB-500 and the combination—. Two things from that work, both with their context:
- The TB-500 group showed higher maximum load to tendon failure, with statistical significance, and better histological scores.
- The combination of the two added no benefit over each one separately. The authors suggest they may converge on the same pathways.
It is a single, exploratory rat study measuring a mechanical property of the tendon, not a clinical outcome. It says nothing about people and makes neither «the best»; if anything, the most useful point is the second one, because it goes against the widespread idea of combining them.
What neither of the two has
Neither BPC-157 nor thymosin beta-4 (or its fragments) has an approved human indication, in the EU or the United States. There are no phase 3 trials that have led to a medicine. Abundant preclinical literature is not the same as clinical evidence: that is the missing step, not a formality.
What to check when comparing suppliers of these two
- With TB-500, identity outranks purity. With two molecules under the same name, what resolves the ambiguity is mass spectrometry identity confirmation of the lot —their molecular weights are very different— and the supplier stating explicitly which one it sells.
- For both, HPLC purity of the specific lot, with a consultable certificate.
- A real cold chain in shipping.
EuroPeptiva sells material intended exclusively for laboratory research. No product is approved for human, veterinary or diagnostic use.