A study found that adding a complete thymic extract (which contains thymosin‑alpha‑1) to low‑motility sperm samples in the lab, or giving it as a 150 mg daily intramuscular shot for a week, boosted both total and progressive sperm movement. The improvements were statistically significant, but the research involved only a small number of samples and volunteers, so the results are preliminary.

The thymic gland is involved in immunologic and endocrinologic heomostasis of the body. Neonatal thymectomy of experimental animals leads to gonadal dysgenesis. Both eostrogen and androgen receptors have been identified in thymic epitelial cells, and sex steroids can be modulated by secretion of thymosin. High levels of thymosin alpha-1 in seminal plasma are correlated with sperm count, viability and motility in fertile males as compared to infertile ones. In this study we examined the effects of complete thymic extract on motility and progressive motility of spermatozoa obtained from asthenozoospermic men. In the first part of experiment, we studied the influence of complete thymic extract, as a bioactive medium component, on movement of spermatozoa samples with initial motility lower than 30%, in vitro. The study was carried out on two groups of sperm samples, 40 samples each, obtained by masturbation after a 72-hour-abstinence. After completed liquefaction at room temperature (30-40 min.), we determined the usual parameters of sperm quality. Total motility (M%) and progressive motility (PM%) of spermatozoa were analyzed in 10 microscopic view fields. Each group of sperm samples was prepared by swim-up and swim-down method. Then, we estimated the total motility and progressive motility of "washed" spermatozoa in every sample. In addition, every sample was divided in two equal parts. One part was immediately left in thermostat (control). To the second part we added 0.2 mg of complete thymic extract before incubation (experimental group). Total and progressive motilities were analyzed after 1, 4, 12 and 24 hours of incubation. The t-test was used for statistical analysis of results. The second part of the study was carried out on a group of 10 asthenozoospermic men (volunteers). We examined the influence of complete thymic extract, as intra-muscular injection, in a doze of 150 mg daily, during seven days, on motility and progressive motility of spermatozoa. Sperm samples were obtained by masturbation after four days of abstinence. We compared the parameters before and after the therapy. They were statistically processed by a method of difference. The results showed that the complete thymic extract increased the total and progressive motilities of spermatozoa separated by swim-down method (p < 0.001), in vitro (Table 1-4). The parenteral application of complete thymic extract, statistically significantly increased motility and progressive motility of spermatozoa in asthenozoospermic men (p < 0.05) (Table 5). These findings could be useful in assisted reproductive technology.