Reference
What is TB-500?
TB-500 is not thymosin beta-4. It is a short synthetic fragment corresponding to part of that 43-residue protein — the two names are used interchangeably in a lot of writing, and they are not the same substance.
Classification
| Type | Peptide |
| Chain length | 7 amino acid residues |
| Family | Thymosin beta-4 fragment |
| Origin | A synthetic fragment of thymosin beta-4, a protein first isolated from thymus tissue in the 1960s |
| Supplied as | Lyophilised powder in a sealed vial |
Thymosin beta-4 itself was isolated from thymus tissue and is found widely in mammalian cells. The fragment sold as TB-500 is made synthetically and is a fraction of the length, which is why it is cheaper to produce and why the two should not be treated as equivalent material.
Where it sits by length
At 7 residues, TB-500 is a short chain — an oligopeptide by the usual convention. The boundary is a convention, not a rule of chemistry — chains up to roughly fifty residues are generally called peptides.
What this page does not cover
Nothing here describes what TB-500 does, what it is used for, or whether it is safe. We publish analytical results and ship parcels; we give no guidance on dosing, preparation or use, and that applies to our reference pages as much as to the product pages. The person to ask about any of that is a registered prescriber.
Where it came from
TB-500 is a synthetic fragment of thymosin beta-4. The parent protein has a clear origin; the fragment’s designation does not.
Parent protein 1981; the fragment, the 2000s — New York, United States. When was TB-500 created?
Further reading
BPC-157 vs TB-500 — two unrelated molecules, compared by origin, length, sequence and research record.
More on TB-500
See TB-500 in the range · What is a peptide? · Discovery timeline · All reference
