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No identified human exposure data for TB-500 fragment
TB-500 is a synthetic peptide fragment (LKKTETQ) related to thymosin beta-4. It is not FDA-approved, and the FDA has flagged the fragment as a potential significant compounding safety risk with no identified human exposure data. This page explains what it is, its regulatory status, and known safety considerations.
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TB-500: reference record
| Regulatory status | Not FDA-approved; FDA lists the TB-500 fragment as a potential significant compounding safety risk |
|---|---|
| Route | No established human route |
| Dosing frequency | No established regimen |
| Published range | No established range |
| Evidence basis | No identified human exposure data for TB-500 fragment |
| Common vial sizes | 2, 5, 10 |
Sources
- U.S. Food & Drug Administration - fda.govBasis for the regulatory status, route, frequency and published range in the table above. Source last checked 2026-06-24
What is TB-500?
TB-500 is a synthetic peptide fragment with the sequence LKKTETQ, related to a region of the larger protein thymosin beta-4. The fragment and the full protein are not the same substance, and evidence about one does not transfer to the other.
Is TB-500 FDA-approved?
No. TB-500 is not FDA-approved, and the FDA has flagged the fragment as a potential significant compounding safety risk. There is no approved product or indication.
How is TB-500 given?
There is no established human route and no established regimen. Nothing published establishes how, or whether, the fragment should be administered to people.
What are the known safety concerns with TB-500?
The FDA has stated it has not identified human exposure data for the TB-500 fragment and lacks safety information for it. That absence of data is itself the finding, and it should not be read as reassurance.
No clinically validated human dose for the TB-500 (LKKTETQ) fragment
No default dose. Do not substitute full-length thymosin beta-4 study doses.
FDA states it has not identified human exposure data for the TB-500 fragment and lacks safety information.
Supply-chain quality · Finnrick
Avg quality score
5.8
/10
Purity range
85.82
–
99.9
%
Qty divergence
±
100
%
Vendors · samples
14
·
102
Common vial sizes
2, 5, 10
mg
Test window
May 2025 - May 2026
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