Thymulin, a zinc-dependent hormone, states at the end of its abstract that “It is not toxic and one may foresee its clinical use as one of the major immunoregulatory agents in the near future.” A study in 2017 entitled Hair Therapy and Transplantation claimed that participants:
showed a significant increase in the number of newly observed intermediate hairs in previous “absent hair” regions (P<0.0001) with an average increase of vellus type (32%) and intermediate type (23%) hairs at 6 months. Melanogenesis was observed in several subjectsThere are a couple of reasons why this can work. One is that it supplements people who may be deficient in Zinc. Zinc Deficiency has been known to cause a number of health issues, one of which being hair loss. However, the more popular idea is due to the fact that Zinc helps in the production of testosterone, which, some believe can help with hair growth. However, other evidence suggests that increased testosterone can cause hair loss. One study showed that “Zinc supplementation of marginally zinc-deficient normal elderly men for six months resulted in an increase in serum testosterone from 8.3 ± 6.3 to 16.0 ± 4.4 nmol/p (p = 0.02). We conclude that zinc may play an important role in modulating serum testosterone levels in normal men.” Pretty much no study has been done in regards to zinc supplementation when it comes to hair loss. One case study showed that a patient who had hair loss not due to deficiency benefited from Zinc supplementation, but more research needs to be done. The evidence for topical Zinc Thymulin is weak at best and non-existent at worst. The only study in existence is done by the same company that provides the treatment options, which can be thousands of dollars for a yearly supply. Based on the lack of evidence for this, I cannot make a conclusion that this product is effective when it comes to preventing hair loss, or encouraging hair regrowth.