What it is
TB-500 is the synthetic form of thymosin beta-4, a peptide that occurs naturally in the body. It is studied for its role in promoting cell migration, angiogenesis, and tissue repair. In the PeptidesAI encyclopedia it is categorized under tissue repair, the same category as BPC-157.
How it's thought to work
The proposed mechanism centers on actin polymerization and cell migration — actin is a protein involved in how cells move and change shape, and TB-500 is studied for promoting this process in a way that is thought to enable tissue repair. It has also been studied for supporting angiogenesis, the formation of new blood vessels, and for reducing inflammation. A further part of the studied mechanism is systemic distribution: rather than staying localized to one site, TB-500 is described as distributed throughout the body, and it has been studied for supporting whole-body recovery on that basis, rather than only the area nearest an injection.
What the research says
Preclinical studies — meaning animal and laboratory research — show tissue repair and anti-inflammatory effects associated with TB-500. Human data on the compound is limited, so the tissue-repair and anti-inflammatory findings described above come from animal and lab research rather than from clinical trials in people.
Reported side effects
Reported side effects are described as rare. Where they are reported, they include fatigue, temporary mood changes, and reactions at the injection site.
Reconstitution
TB-500 is supplied as a lyophilized (freeze-dried) powder and is typically reconstituted with bacteriostatic (BAC) water before use. It commonly comes in 5 mg and 10 mg vials. Reconstitution follows the same dilution calculation regardless of which of those two vial sizes is on hand: the amount of peptide in the vial is fixed, and the water added only changes how concentrated the resulting solution is.
Worked example. A 5 mg vial is 5,000 mcg. Reconstituted with 1 mL of BAC water, that works out to 5,000 mcg ÷ 1 mL = 5,000 mcg/mL. On a U-100 insulin syringe, where each unit is 0.01 mL, that means each unit holds 5,000 × 0.01 = 50 mcg. A 10 mg vial reconstituted with 2 mL of BAC water comes out to the same concentration — 10,000 mcg ÷ 2 mL = 5,000 mcg/mL, so again 50 mcg per unit — because the ratio of peptide to water is unchanged. Use the peptide reconstitution calculator to work out the concentration and units for any vial size and water volume.
Important notes
Two important notes apply to TB-500: it is a substance prohibited by the World Anti-Doping Agency (WADA), which is relevant for anyone subject to anti-doping testing, and it is not approved by the FDA for any human use.
Frequently asked questions
These questions cover the same ground as the sections above, in a shorter format.
What is TB-500?
A synthetic version of thymosin beta-4, a naturally occurring peptide studied for promoting cell migration, angiogenesis and tissue repair. It is a research compound, not approved by the FDA for human use.
How is TB-500 thought to work?
Research describes it as promoting actin polymerization and cell migration, supporting angiogenesis, and reducing inflammation, with systemic distribution studied for whole-body recovery support.
What does the research on TB-500 say?
Preclinical (animal and lab) studies show tissue repair and anti-inflammatory effects. Human data is limited.
What are the reported side effects?
Rare — fatigue, temporary mood changes, and injection site reactions.
How many mcg is one unit from a 5 mg TB-500 vial?
With 1 mL of BAC water, a 5 mg vial is 5,000 mcg/mL, so one unit on a U-100 syringe (0.01 mL) holds 50 mcg.
The full entry, plus the calculator
The PeptidesAI app has the complete encyclopedia entry for TB-500 — one of 70 compounds covered — including protocol notes, plus the reconstitution calculator, a dose log and reminders. Free to download on iPhone.
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