Thymosin Beta-4
Tissue Repair and Healing
ABOUT
Recombinant human thymosin beta-4 has been evaluated in a first-in-human phase I trial in healthy volunteers, focused on short-term safety, tolerability, pharmacokinetics, and anti-drug antibodies.
EVIDENCE OVERVIEW
Early human findings, not yet confirmed
WHAT THIS MEANS
Potential. Review the research and limitations before relying on this record.
IDENTITY
HALF-LIFE
HOW IT IS THOUGHT TO WORK
Thymosin beta-4 is a 43-amino-acid actin-monomer-sequestering protein present in most cell types. It modulates the pool of actin available for polymerisation, and has separately been described as an anti-inflammatory agent and an inhibitor of bone-marrow stem-cell proliferation. Only the actin interaction has an identified molecular basis; the other effects are described without one.
PHARMACOKINETICS
A first-in-human randomised double-blind single- and multiple-dose phase 1 study of recombinant human thymosin beta-4 in healthy volunteers characterised pharmacokinetics along with safety and anti-drug antibodies - the one place in this record where administered exposure was actually measured. Published reviews separately discuss how hard it is to quantify circulating endogenous thymosin beta-4 reliably, which is why observational levels should not be read as pharmacokinetic data.
REVIEW
PUBLISHED PAIR RECORDS
with BPC-157
Commonly combined tissue-repair peptides with no combination evidenceBPC-157 and Thymosin beta-4 are frequently used together for tissue repair, and this is one of the few combinations in this catalogue with any human report at all: a retrospective chart review of knee-pain patients administered both together. That report had no control group, no randomisation, and cannot separate the contribution of either peptide - so it documents that the combination has been used, not that it works. A 2025 systematic review found one clinical study against 35 preclinical animal studies for BPC-157. Neither compound has a published human pharmacokinetic profile, so no exposure-based reasoning about combining them is possible. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026with TB-500
Same molecule family: fragment and parent proteinTB-500 and thymosin beta-4 are not two agents - TB-500 is a short synthetic fragment corresponding to the actin-binding region of the 43-amino-acid thymosin beta-4 protein. Treating them as a combination assumes two mechanisms where the evidence describes one, and the two are routinely conflated in marketing material. The distinction that does matter runs the other way: human trial data exists for full-length thymosin beta-4 (a phase 1 study in healthy volunteers, an intravenous study after acute myocardial infarction, phase 2 topical eye drops) and none exists for the fragment, so pharmacokinetic and safety findings for the parent protein cannot be read across to TB-500. Both are prohibited at all times in sport, TB-500 by name. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 21 Aug 2026with KLOW
Inherited from a component of this blendKLOW contains BPC-157 and TB-500, and the catalogue holds a curated pair record between those components and Thymosin Beta-4: BPC-157 (commonly combined tissue-repair peptides with no combination evidence); TB-500 (same molecule family: fragment and parent protein). Taking the blend therefore carries the same consideration as taking that component on its own, with the difference that a fixed-ratio vial cannot be adjusted independently of the rest of its contents. The evidence and citations here are the component record's; nothing has been studied about the blend itself. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 25 Aug 2026with GLOW
Inherited from a component of this blendGLOW contains BPC-157 and TB-500, and the catalogue holds a curated pair record between those components and Thymosin Beta-4: BPC-157 (commonly combined tissue-repair peptides with no combination evidence); TB-500 (same molecule family: fragment and parent protein). Taking the blend therefore carries the same consideration as taking that component on its own, with the difference that a fixed-ratio vial cannot be adjusted independently of the rest of its contents. The evidence and citations here are the component record's; nothing has been studied about the blend itself. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 25 Aug 2026with Wolverine blend
Inherited from a component of this blendWolverine blend contains BPC-157 and TB-500, and the catalogue holds a curated pair record between those components and Thymosin Beta-4: BPC-157 (commonly combined tissue-repair peptides with no combination evidence); TB-500 (same molecule family: fragment and parent protein). Taking the blend therefore carries the same consideration as taking that component on its own, with the difference that a fixed-ratio vial cannot be adjusted independently of the rest of its contents. The evidence and citations here are the component record's; nothing has been studied about the blend itself. Peppy reports curated pharmacology, not a safety verdict. A prescriber or pharmacist should review any intended combination.
Reviewed 25 Aug 2026HUMAN EVIDENCE
Full-length thymosin beta-4 has reached human trials: the phase 1 study above in healthy volunteers, an intravenous safety and tolerability study in patients after acute myocardial infarction, and phase 2 trials of topical 0.1% thymosin beta-4 eye drops (RGN-259) in dry eye disease reporting improvement in corneal staining and tear-film break-up time against placebo. None of this has produced an approval for any indication.
REPORTED EFFECTS
Tolerability in the completed trials was acceptable, but they were small and short, and anti-drug antibody formation is a specific question for a recombinant protein that the phase 1 study was designed to look at. Thymosin beta-4 and its derivatives are prohibited at all times in sport. No regulator has approved this substance for the use described here, so there is no label-verified dose, purity standard, or safety monitoring requirement behind it.
RESEARCH LIMITATIONS
A phase I study cannot establish clinical benefit or long-term safety. Findings for recombinant study material should not be assumed to apply to other preparations.
CURATED SOURCES · 4