Origins
When was TB-500 created?
TB-500 is a synthetic fragment of thymosin beta-4. The parent protein has a clear origin; the fragment’s designation does not.
The short answer
| Date | Parent protein 1981; the fragment, the 2000s |
| Who | Allan Goldstein’s group described the parent protein |
| Where | New York, United States |
| Origin | Derived from a larger natural molecule, then made synthetically. |
Where it came from
Thymosin beta-4 was isolated in 1981 from the same thymus fraction that had yielded thymosin alpha-1 nine years earlier. It is a forty-three-residue protein, and despite sharing the thymosin name it is unrelated to thymosin alpha-1 — the shared name records which tube they came out of, not any kinship.
TB-500 is a short sequence corresponding to a region of that protein, made synthetically. On the specific question of when the designation TB-500 was coined, and by whom, the record is genuinely poor. It appears in research-chemical and veterinary supply from the 2000s onward; it is not an international nonproprietary name and it does not correspond to a published development programme the way a code such as CJC-1295 or SS-31 does.
Stating that plainly is more useful than inventing a date. What can be said with confidence is the parent protein, its year, and the fact that the fragment is not the protein — a vial of TB-500 does not contain thymosin beta-4.
Why it is called that
TB for thymosin beta. The 500 has no documented derivation that we have been able to establish.
Where it stands now
TB-500 has not been approved as a medicine anywhere and is on the World Anti-Doping Agency’s prohibited list.
What this page does not say
Nothing above is a statement about what TB-500 does in a body, and none of it is guidance on use. A compound’s history is a record of laboratories and dates; it is not evidence for anything, and the fact that a programme was looking for something is not a finding that it was found.
More on TB-500
What is TB-500? · The full timeline · TB-500 — sizes and prices
