TB-500 and Hair Growth: What Has Been Studied

What the research covers

No published study was found that tested TB-500 for hair growth in people. The hair data come from rodent (rat) and rodent (mouse) studies. They used thymosin beta-4, the natural protein behind TB-500. The main part of TB-500 is a short lab-made peptide called LKKTETQ, with an acetyl group added at one end. It matches amino acids 17 to 23 of thymosin beta-4. The full protein has 43.

In a 2004 study, thymosin beta-4 made hair grow in normal rodent (rat) and rodent (mouse) models. The authors tied the effect to stem cells in the hair follicle. In a 2015 rodent (mouse) study, animals bred to make extra thymosin beta-4 regrew hair faster. Animals bred without it regrew hair more slowly. These studies used the full protein, not TB-500.

One human study put thymosin beta-4 in a mix. In 2018, 1,000 patients had scalp shots of a six-part mix every 3 weeks, for 8 sessions. The study had no placebo group. Hair fall dropped in 83% of patients on a pull test. With six parts and no control group, it cannot show what thymosin beta-4 did on its own.

A PubMed search on 27 September 2026 found no study of TB-500 for hair or hair loss. ClinicalTrials.gov listed no hair trial of TB-500 or thymosin beta-4 on the same date.

Sources

1. Kapoor R, Shome D Intradermal injections of a hair growth factor formulation for enhancement of human hair regrowth - safety and efficacy evaluation in a first-in-man pilot clinical study. J Cosmet Laser Ther (2018). PMID 29482481 doi:10.1080/14764172.2018.1439965
2. Ruff D, Crockford D, Girardi G, et al. A randomized, placebo-controlled, single and multiple dose study of intravenous thymosin beta4 in healthy volunteers. Ann N Y Acad Sci (2010). PMID 20536472 doi:10.1111/j.1749-6632.2010.05474.x
3. Philp D, Nguyen M, Scheremeta B, et al. Thymosin beta4 increases hair growth by activation of hair follicle stem cells. FASEB J (2004). PMID 14657002 doi:10.1096/fj.03-0244fje
4. Philp D, St-Surin S, Cha HJ, et al. Thymosin beta 4 induces hair growth via stem cell migration and differentiation. Ann N Y Acad Sci (2007). PMID 17947589 doi:10.1196/annals.1415.009
5. Gao X, Liang H, Hou F, et al. Thymosin Beta-4 Induces Mouse Hair Growth. PLoS One (2015). PMID 26083021 doi:10.1371/journal.pone.0130040
6. Ho EN, Kwok WH, Lau MY, et al. Doping control analysis of TB-500, a synthetic version of an active region of thymosin β₄, in equine urine and plasma by liquid chromatography-mass spectrometry. J Chromatogr A (2012). PMID 23084823 doi:10.1016/j.chroma.2012.09.043
7. Esposito S, Deventer K, Goeman J, et al. Synthesis and characterization of the N-terminal acetylated 17-23 fragment of thymosin beta 4 identified in TB-500, a product suspected to possess doping potential. Drug Test Anal (2012). PMID 22962027 doi:10.1002/dta.1402