Metabolic syndrome and testosterone: how it improves sexual health too

The discovery comes from the University of Catania: tirzepatide, one of the molecules used in the treatment of diabetes and obesity, may also have a positive effect in the treatment of metabolic hypogonadism in men. This is a condition in which the body is unable to produce adequate levels of testosterone, the male sex hormone, and in some cases is caused by an underlying metabolic syndrome. In other words, men with metabolic syndrome are more likely to have low testosterone levels. Currently, the standard treatment for metabolic hypogonadism is testosterone replacement therapy, typically administered via transdermal patches. Now, however, research presented at the Endocrine Society meeting (Endo 2025) demonstrates that tirzepatide, a GLP-1 receptor agonist, has superior results compared to replacement therapy.

Results after two months

The study, published in Reproductive Biology and Endocrinology , was conducted by researchers led by Rossella Cannarella of the Department of Clinical and Experimental Medicine at the University of Catania. The analysis was conducted on 83 obese men with functional hypogonadism and insulin resistance. Participants were divided into three groups: 28 received tirzepatide (2.5 mg the first month, increased to 5 mg the second), 30 received no medication, and 25 were treated with transdermal testosterone. All participants followed a low-calorie diet and walked briskly for 20 minutes daily. After just two months of treatment, the group treated with the GLP-1 receptor agonist showed significantly greater improvements than the other groups in several areas. First and foremost, weight loss was greater (-8.1%) compared to -2.4% in the untreated group and -3% in the transdermal testosterone group. The tirzepatide group also showed a greater increase in lean mass than the group treated only with diet and exercise, and an improvement in compulsive eating behavior (binge eating).

It also improves sexual health

All groups also showed reductions in insulin resistance, with the reductions being greater in the two drug-treated groups. But the most striking result was in levels of LH, the luteinizing hormone that stimulates testosterone production in the testes in men, FSH (follicle-stimulating hormone, which stimulates sperm production in men), and total testosterone, which were significantly higher in the tirzepatide group than in the other two. Furthermore, men treated with the GLP-1 agonist also showed an improvement in erectile dysfunction, a major issue in people with metabolic syndrome and not necessarily improved by testosterone therapy.

Action on metabolic causes

This is why, Cannarella explains to Medscape , tirzepatide offers a dual benefit: substantial weight loss and restoration of gonadal function in obese men. The reasons for this advantage lie in the molecule's mechanism of action. Unlike testosterone replacement therapy, tirzepatide appears to restore the function of the hypothalamic-pituitary-gonadal axis, the neuroendocrine system that regulates reproductive function and the production of sex hormones. According to the researchers, this is essentially a paradigm shift: rather than simply replacing missing testosterone, the researchers conclude, the GLP-1 agonist drug addresses the metabolic causes underlying hypogonadism in obese men.