Is TB-500 FDA approved?

No. As of 23 September 2026, neither the US FDA nor the EMA holds a record of an approved TB-500 medicine. FDA names the thymosin beta-4 fragment LKKTETQ, also known as TB-500, on its compounding safety-risk list and says it has identified no human exposure data. No FDA Philippines advisory names it.

Primara Labs sells some of the compounds covered here. Every figure on this page links to its source and the date it was checked.

Updated 23 September 2026

What FDA wrote about TB-500

FDA's compounding page (current as of 22 April 2026) lists "Thymosin beta-4, fragment (LKKTETQ), also known as TB-500" and says: "Compounded drugs containing thymosin Beta-4, Fragment (LKKTETQ) may pose risk for immunogenicity for certain routes of administration due to the potential for aggregation as well as peptide-related impurities. FDA has not identified any human exposure data drug products containing Thymosin Beta-4, Fragment."

Drugs@FDA holds "no record found" for thymosin beta-4, its fragment or TB-500, and the EMA medicines report holds "no record found".

A naming problem worth knowing

TB-500 is not the same molecule as full-length thymosin beta-4. Human trials, including eye-drop studies, used the 43-amino-acid protein, while the analytical literature identifies TB-500 as a short acetylated fragment. The Research Desk therefore rates TB-500's evidence as animal and cell, and the full-length protein's human work does not transfer to it.

Philippines

Searches of fda.gov.ph for "TB-500" and "thymosin" on 23 September 2026 returned no advisory. The registration record could not be read from the FDA Philippines verification portal that day.

The animal work

In aged and diabetic mice, the seven-amino-acid thymosin beta-4 fragment LKKTETQ promoted skin wound repair about as well as the full-length protein.

Animal and cell studies only for TB-500. Human trials exist for full-length thymosin beta-4, a different molecule, mostly as eye drops; see the Evidence Map.

A cell study on the molecule itself

In a cell scratch-wound test, the TB-500 breakdown product Ac-LKKTE showed wound-healing activity, while TB-500 itself did not.

This is general information, not legal advice.

Sources

Where every figure comes from

US FDA record for TB-500 · checked 23 September 2026
EMA record for TB-500 · checked 23 September 2026
FDA, bulk drug substances that may present significant safety risks in compounding · checked 23 September 2026
FDA Philippines site search, TB-500 · checked 23 September 2026

Last reviewed 23 September 2026