Before you ask: Thymidine beta 4 or TB-500, there is no difference between the two molecules. The only difference between TB 500 and Thymosin Beta 4 is that the latter is produced by the thymus gland in the body, and the former is produced synthetically in the lab. A bonus point for peptide labs which call it the proper way. However it's the same ...
Thymosin beta 4 (Tβ4 / TB-500) increase hair growth in vitro by accelerating angiogenesis
Tβ4 plays an important role in cell motility [
2,
3], and has multiple biological activities, such as promoting angiogenesis [
4,
5], wound healing [
4], hair growth [
8,
9] and anti-apoptosis [
10] and more. It has been reported in rats and mice that exogenous Tβ4 plays an important role in wound healing and hair growth [
11]. When studying the influence of Tβ4 on wound healing, Philp et al. accidentally found that hair grew more rapidly around the edges of wounds.
It was subsequently shown that Tβ4 induced rapid hair growth on the dorsal skin of athymic mice and depilated regions of rats and mice. Similarly, rat whiskers grown in vitro grow rapidly when treated with Tβ4 [
9]. When examining the distribution of endogenous Tβ4 expression during the sequential phases of depilation-induced hair growth, high levels of Tβ4 expression were observed in the developing hair follicles (HFs). Additionally, Tβ4 expression is also high in the developing HFs of mice and clonogenic mice HF keratinocytes cultured in vitro for 7–10 days [
9,
12]. The generation of Tβ4 transgenic mice confirmed that Tβ4 promotes hair growth [
12].
While it is apparent that Tβ4 plays a role in hair growth and its molecular mechanism is unknown. To explore the role of Tβ4 in HF development, we generated mice that overexpress Tβ4 in the epidermis (KTP mice) and Tβ4 global knockout mice (KO mice). Mechanistically, it has been shown that Tβ4 accelerates angiogenesis by increasing vascular endothelial growth factor (VEGF) expression [
13], which may be secondary to the effects of Tβ4 on MAPK, PKC and WNT signaling [
14]. Thus, we also explored the relationship between Tβ4 and VEGF expression in the skin, and dissected the underlying signaling pathways associated with this effect.
Also see;
"Thymosin beta4 increases hair growth by activation of hair follicle stem cells."
https://www.ncbi.nlm.nih.gov/pubmed/14657002
"Thymosin Beta-4 Induces Mouse Hair Growth"
https://journals.plos.org/plosone/article?id=10.1371/journal.pone.0130040
"Role of thymosin beta 4 in hair growth"
https://link.springer.com/article/10.1007/s00438-016-1207-y
"Thymosin Beta 4 Induces Hair Growth via Stem Cell Migration and Differentiation"
https://nyaspubs.onlinelibrary.wiley.com/doi/pdf/10.1196/annals.1415.009