Evidence is limited to animal or in-vitro work. No human pharmacokinetics. Any human dose in circulation is extrapolated, and extrapolation across species routinely fails.
These values are for RECOMBINANT HUMAN THYMOSIN BETA-4 (the full 43-amino-acid protein), NOT for "TB-500" as sold. First-in-human Phase 1: single IV doses 0.05-25 mcg/kg gave tmax 3-15 min and t½ of 0.5-2.08 h, rising with dose. Multiple-dose over 10 days showed no obvious accumulation. IDENTITY TRAP: "TB-500" on the grey market is typically the synthetic 7-amino-acid fragment Ac-LKKTETQ, a DIFFERENT molecule. These values do not transfer to it, and no human PK for the fragment exists.
No approved dose. Sourced human exposures are weight-based IV (0.05-25 mcg/kg) for recombinant Tβ4. A separate Phase 1 programme used IV doses of 42-1260 MILLIGRAMS, a completely different scale, which underscores that no consensus human dose exists. Community "TB-500" protocols (2-5 mg/week) are anecdotal and apply to a different molecule.
In the recombinant Tβ4 Phase 1 all adverse events were mild to moderate with no dose-limiting toxicities and no accumulation on repeat dosing, but this covers only short exposure in healthy volunteers. Tβ4 is pro-angiogenic and pro-migratory; theoretical oncologic concern is unstudied in humans long-term. Efficacy for the musculoskeletal repair claims made in the community is NOT established in humans. Grey-market "TB-500" is a different molecule of unverified identity and purity.