TB-500 references: every cited study behind the readouts on this site.

How to read this register

Every quantitative claim on this site maps to a numbered entry below. The regulatory facts on the TB-500 legal status and FDA 503A category page are cited to FDA primary sources (entries 16-18). Where a research finding used full-length thymosin beta-4 rather than the Ac-LKKTETQ fragment, the body copy carries that flag — the identity caveat is the spine of this whole digest, and it is preserved in how each study is described. The full citations follow in the references list.

What each entry is, and what it is not

The register sorts into three layers. The mechanistic anchor is the actin-sequestration structure — the gelsolin-domain-1–thymosin beta-4 hybrid resolved to 2 Å that established 1:1 G-actin capping ^[1] — together with the consolidating review of thymosin beta-4 biology ^[5]. The repair and signaling findings are the wound, cardiac, neurological, angiogenic, and matrix-remodeling studies ^{[2][3][4][10][11][12][13]}, almost all of which used the full-length parent protein in animals or in vitro. The safety and null layer is what keeps the picture honest: the tumor-metastasis and pancreatic-cancer overexpression findings ^[7][8], the mdx-mouse result with more regenerating fibers but no strength gain ^[9], and the porcine ischemia-reperfusion null ^[14].

Two entries do work that the rest cannot. The Phase 1 intravenous study ^[6] is the only randomized, placebo-controlled human safety dataset here — and it is for full-length thymosin beta-4, not the fragment. The 2026 Sports Medicine review ^[15] is the current secondary read on where TB-500 and its peers sit: favorable animal tissue-repair signals, scarce human safety data, largely outside regulatory oversight. None of these entries is a clinical endorsement, and none establishes efficacy of the Ac-LKKTETQ heptapeptide in humans ^[5]. They are the published record, listed so any claim on this site can be checked against its source.