Is there an FDA-approved TB-500 product?
No FDA-approved product
The record found no FDA-approved product. A label that says research use only does not make a product approved for people.
What the record says: No FDA-approved TB-500 drug product
Legal status · Record reviewed
Is TB-500 legal in the U.S.?
Short answer
TB-500 has no single legal status. It depends on the product and how it is supplied.
No FDA-approved TB-500 drug product. A research use only label does not make a product approved for people.
Pharmacy mixing (compounding): FDA had placed it in Category 2 for possible safety risks, and the request was then withdrawn (FDA page dated April 22, 2026).
Sports: the anti-doping rules we checked list it as prohibited (checked August 1, 2026).
Rules for buying, selling, and prescribing also depend on how a product is made and sold, and on state law.
This is not legal advice.
Whether you may buy, sell, or use a product also depends on pharmacy (compounding) rules, a prescription, and state law. Read how U.S. peptide law works.
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The three records behind this answer
Is it on FDA's compounding safety list?
Nomination withdrawn
Listed as thymosin beta-4, fragment (LKKTETQ), also known as TB-500.
FDA had placed it in Category 2 for possible safety risks. The person who asked FDA to allow it in compounding then withdrew the request. FDA still lists its safety concerns and has not made a final decision. A withdrawn request is neither a ban nor an approval.
Source: FDA's page of bulk drug substances that may present significant safety risks. FDA marks it current as of . We checked it on .
Do sports rules ban TB-500?
Prohibited
TB-500 is named as a prohibited thymosin-beta-4 derivative on the 2026 WADA Prohibited List and is prohibited at all times for covered athletes.
Checked . Read the rule we checked. Check the current World Anti-Doping Agency list and your sport's rules before you compete.
Other names in this record: TB500, Ac-LKKTETQ, thymosin beta-4 fragment 17-23.
Go further
Read the full TB-500 record
What it is, what studies in people show, and what is still unknown.
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