Thymosin Beta 4(Tβ4) is a peptide hormone secreted by the thymus gland. It plays an important role in tissue repair at various sites around the body, and for many medical conditions. It is comprised of 43 amino acids . Studies have been able to determine that amino acids 1-4 are responsible for its anti-inflammatory and antifibrotic (countering cellular damage) effects. The first fifteen amino acids together inhibit apoptosis (cell death) after injury and reduce toxicity induced damage to cells. Finally, amino acids 17–23 trigger angiogenesis (new blood vessel formation) and growth of hair follicles. These abilities make Tβ4 a potent natural weapon in the fight against many health conditions and injuries as documented below.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8228050/

Therapeutically, Thymosin beta-4 is used clinical for recovery not only a wide variety of injuries but also in conjunction with PRP (Platelet Rich Plasma) and stem cell procedures to enhance the healing of ligaments and tendons, as well as in hair restoration.
Thymosin Beta-4 plays a role in many crucial physiological processes in the body, namely, increasing angiogenesis (new blood vessel formation) and proliferation, and inhibiting apoptosis (cell death), and it works to reduce inflammation.
THE PHYSIOLOGIC ACTIONS AND CLINICAL APPLICATIONS OF THYMOSIN BETA-4

Angiogenesis

Tβ4 promotes angiogenesis (new blood vessel formation) enhancing immature progenitor cells, and triggering the proliferation and migration of new cells to create the blood vessel’s structure. Vascular endothelial growth factor (VEGF) is an important naturally secreted factor promoted by Tβ4 which assists in the process of angiogenesis, and induces cellular proliferation, and migration of new endothelial cells and increasing vascular permeability and blood flow into the healing of injured tissues in the lab.
Tβ4, Cell Proliferation and the Cell Cycle
Tβ4 treatment enhances the proliferation of mesenchymal stem cells- thus its use with PRP and stem cell therapies. Furthermore, Tβ4 enhances the proliferation of oligodendrocyte (nervous system) progenitor cells (OPCs) and their maturation into myelinating (mature) oligodendrocytes-nervous system cells.
In the lab the Tβ4 accelerates vascular endothelial cell proliferation, thereby protecting post-ischemic cardiac function. Tβ4 has been shown in lab research to be effective for inhibiting the damage caused by myocardial infarction and myocardial ischemia, liver and renal fibrosis, ulcerative colitis, and skin trauma.

Tβ4 Ameliorates Inflammation

Tβ4 ameliorates inflammatory reactions. In models of liver injury mediated by ethanol and lipopolysaccharide, Tβ4 prevented the production of proinflammatory cytokines such as tumor necrosis factor-α (TNF-α), IL-1β, and IL-6.
Tβ4 exhibits anti-inflammatory activities in different pathologies, reducing inflammation in the brain , liver, eye, and heart diseases.

Tβ4 and Signaling Pathways

Tβ4 affects the secretion of multiple cytokines and regulates various signaling pathways. It alleviates inflammatory damage.
In a study of 143 patients with chronic cutaneous full thickness pressure ulcers, and venous stasis ulcers The results showed that Tβ4 accelerated healing by almost a month in patients who healed. Another double-blind, placebo-controlled study was conducted at eight European locations They had study recruited 73 randomly assigned patients. There results showed that Tβ4 accelerated wound healing, and 25% of patients healed completely within 3 months.

Protective Effect of Tβ4 on the Liver

In another study Tβ4 prevented ethanol mediated oxidative stress. They found that it decreased harmful reactive oxygen species and breakdown of lipid layers of the cells, increasing antioxidant levels.
Liver fibrosis typically occurs in response to hepatic injury. Several studies have reported that Tβ4 treatment has an antifibrotic effect on the liver.

Tβ4 Promotes Hair Growth

The activity of Tβ4 has been closely related to hair follicle development and hair growth. Research has shown that Tβ4 may act on hair follicle reconstruction-it accelerates hair growth by increasing the proliferation of outer hair follicle root sheath cells. The hair follicles grew better and proliferated faster. With this known activity TB-4 is a companion treatment for hair restoration via PRP and/ or stem cell procedures. https://pubmed.ncbi.nlm.nih.gov/14657002/

Tβ4 Alleviates Renal Fibrosis

Chronic kidney disease is characterized by abnormalities in renal structure or function that last for more than 3 months and has an adverse impact on the health of the patient Tβ4which is naturally secreted in the body is dispensable in healthy kidneys. It has been shown that contrast, a lack of Tβ4 exacerbated kidney disease in lab models. The administration of exogenous Tβ4 was helpful in lab studies for kidney diseases such as glomerulonephritis, diabetic nephropathy, and hypertensive nephropathy. https://pubmed.ncbi.nlm.nih.gov/29727205/
Effect of Tβ4 on Ulcerative Colitis and Colon Cancer

Tβ4 is expressed in the human intestine, where it modulates the intestinal immune system. Moreover, it is considered to be effective in treating gastrointestinal disorders . In a mouse colitis model resembling Crohn’s disease, AAV-Tβ4-treated mice displayed distinctly attenuated colon injuries and reduced the apoptosis rates in colonic mucosal epithelia. AAV-Tβ4 significantly reduced inflammatory cell infiltration and alleviated oxidative stress in the colon.

Thymosin Beta-4 is an endogenous repair factor that is activated during tissue damage. This peptide exerts various biological activities, such as inhibition of inflammation and promotion of cellular proliferation and angiogenesis (new blood vessel growth). Because of its many potential applications in clinical medicine, it is a candidate to assist in the development of new medications for various clinical indications in the near future. https://pubmed.ncbi.nlm.nih.gov/26096726/