Muscle. One research area with great potential is the effects of TB-500 on muscle, but not just skeletal muscle. Thymosin-beta 4 appears to exert promising positive effects on both skeletal muscle and cardiac (heart) muscle.
In one 6-month mouse study, researchers found that thymosin-beta 4 administration improved skeletal muscle fiber regeneration in mice who were deficient in dystrophin, a connective tissue protein [6].
It also may help to protect cardiac muscle and promote repair after damage to the heart through a number of mechanisms [7].
Connective tissue. Because of its effects on body proteins, TB-500 may also provide some potential benefits for connective tissue like joints, tendons, and the collagen matrices that anchor the skin, muscles, and organs.
In one animal study, researchers treated incision wounds on rats with thymosin-beta 4. They also kept an untreated control group to compare how the wounds healed differently. In the wounds treated with thymosin-beta 4, the researchers noted that there was minimal scarring present compared to the controls, and that the treated wounds were also much narrower in width.
Upon closer inspection, they were able to determine that this was because the thymosin beta-4 treated wounds had more tightly organized collagen fibers that were more mature, while the controls had more disorganized arrangements of collagen fibers that appeared to be less mature.
Thymosin-beta 4 administration appeared to significantly improve collagen structure and hasten its maturity, resulting in improved wound healing and reduced scarring [8].
Vasculature and endothelial function. Vasculature refers to blood vessels, and the endothelium is the inner lining of each vessel that helps to regulate blood flow and blood pressure through constriction and dilation. Healthy blood vessels are flexible with highly functioning endothelial linings.
Animal and test-tube models have indicated that thymosin beta-4 can help promote the growth and development of new blood vessels in a process known as neovascularization, but they can also help promote endothelial cell differentiation to help maintain or restore endothelial function in damaged vessels [9, 10].
Other effects. Other animal studies point to even more potential applications for TB-500 and thymosin-beta 4. One mice study noted that thymosin-beta 4 administration helped to improve blood glucose control and increase insulin sensitivity in mice. Researchers also noted improvements in triglyceride levels with thymosin-beta 4 administration in this study [11].
Thymosin beta-4 has also been used to promote hair growth in mice, so it also shows promise as a follicle stimulator for hair loss conditions [12].
It is important to recall that all of this research is considered pre-clinical, and there hasn’t yet been a great deal of research in humans. Although test-tube and animal studies can reveal some of the potential effects of TB-500, it is important to note that these effects have not been confirmed in human subjects.
Human trials. A handful of high-quality, randomized controlled trials have investigated the effects of thymosin beta-4 administration in humans.
One studied venous ulcers, which are a result of poor circulation and typically manifest on the lower leg. With 73 participants in all, researchers found that a dose of 0.03% synthetic thymosin-beta 4 increased the rate of wound healing, and helped 25% of patients achieve full healing within 3 months [13].
Another investigated the effects of thymosin-beta 4 eye drops for severe dry eye. Among nine participants, researchers found that — after 56 days of treatment — the treatment group had a 35% reduction in eye discomfort, 59% improvement in dry eye testing parameters and increased tear production [14].
There has also been one trial in healthy adults to help assess the safety and potential side effects of thymosin-beta 4, and some early pilot and exploratory studies in regards to thymosin-beta 4 and cardiac function [15, 16].