TB-500 dosage: why there isn't an approved one

A “TB-500 dosage” page is an unusual thing to write honestly, because the honest answer is that there isn’t one. TB-500 is the recovery-community name for a synthetic fragment marketed as thymosin beta-4 (Tβ4). It has never been approved as a drug for injury, tendon or muscle recovery, so no regulator has set a dose, a schedule, or a label. What circulates online is a folk protocol, not a prescription. For what the molecule actually is — and where the real evidence sits — start with the TB-500 and thymosin beta-4 evidence monograph.

There is no approved human dose

This is the single most important point on the page. TB-500 is sold as a “research chemical,” a category that exists precisely because the substance is not an approved medicine. There is no manufacturer label, no titration guidance, no FDA-sanctioned dosing range, and no human efficacy trial for the athletic-recovery use that drives sales. Any milligram figure attached to TB-500 for muscle or tendon repair is borrowed from forums and vendors, not from a regulatory record.

What the real human trials actually dosed

Thymosin beta-4 has reached genuine human studies — but the doses, routes and indications bear no relationship to the bodybuilding injection. The strongest randomized human data is in the eye: a Phase 2 trial used a Tβ4 ophthalmic solution dosed as eye drops for severe dry-eye disease.^[1]In wound care, a European randomized study and a clinical series applied Tβ4 topically to venous leg ulcers rather than injecting it for systemic recovery.^[2][3] And the pharmacology that does exist for systemic Tβ4 comes from a first-in-human Phase I study of recombinant human thymosin β4 in healthy volunteers — a carefully escalated single- and multiple-dose safety study, not a recovery regimen.^[4] None of these defines a dose for the “TB-500” sold in vials.

The community “protocol,” described — not recommended

For transparency about what people actually reference, the most commonly shared community pattern is a two-phase one: a loading phase of a larger weekly amount split across the week for the first several weeks, followed by a smaller maintenance phase at intervals thereafter, with weekly totals usually quoted somewhere in the low-single-digit milligram range. We are describing this only so readers can recognize it — it is anecdotal, it traces back to no controlled human trial, and it is not a dose this site endorses. The numbers vary widely from vendor to vendor precisely because there is no evidence base anchoring any of them.

Reconstitution and administration, in context

Research-grade peptides ship as a lyophilized (freeze-dried) powder that must be reconstituted with bacteriostatic water before any subcutaneous use, and the resulting concentration determines how a dose maps to insulin-syringe units. We built a peptide reconstitution calculator to make that arithmetic transparent — vial milligrams plus diluent volume yields concentration and units per dose. Note carefully what it is: a math tool, not dosing advice. It tells you how to compute a volume from a target amount; it does not tell you that any amount of an unapproved research peptide is safe to inject, and the underlying sterility and quality of an unregulated vial are entirely outside any calculator’s scope.

Prohibited in sport

Anyone who competes should treat the dosage question as moot: TB-500 is prohibited by the World Anti-Doping Agency. Thymosin β4 and its analogues fall under the WADA Prohibited List’s peptide/growth-factor provisions and are banned both in and out of competition. (WADA Prohibited List) Using it is a sanctionable anti-doping violation, irrespective of any dose.

Safety and supervision

Because the recovery use has no human safety trials, the long-term risks of repeated TB-500 injection are genuinely unknown — a concern compounded by the fact that the product is unregulated, so the milligrams on the label are not guaranteed to be the milligrams in the vial, and sterility cannot be assumed. The early human pharmacology that exists is a short, supervised, dose-escalation safety study, not a sanction for indefinite self-administration.^[4] Any decision involving this peptide belongs with a qualified clinician who can weigh the absence of evidence, not with a forum dosing chart.

The honest bottom line

TB-500 has no FDA-approved human dose. The defined doses that appear in the thymosin β4 literature are for eye drops, topical wound treatment, and an early safety study — none of which translate to a vial you inject for recovery.^[1][4] The loading-then-maintenance protocol passed around online is anecdotal and unvalidated, the product is unregulated, and the substance is banned in sport. Treat any number you see as a description of community behavior, not a recommendation — and take the dosing question to a clinician, not a forum.