From the Guidelines
Testosterone supplementation can significantly decrease sperm count, and therefore, it should not be prescribed for men interested in current or future fertility. When men take exogenous testosterone, it signals the brain that there's enough testosterone in the system, which suppresses the natural production of hormones that stimulate sperm production, as noted in the 2021 guideline by the American Urological Association and the American Society for Reproductive Medicine 1. This negative feedback loop causes the pituitary gland to reduce the release of follicle-stimulating hormone (FSH) and luteinizing hormone (LH), which are essential for sperm production in the testes.
Some key points to consider:
- The decrease in sperm count is typically dose-dependent and can occur within a few months of starting testosterone therapy.
- This effect is usually reversible when testosterone supplementation is discontinued, though recovery can take several months to a year.
- Men who are concerned about fertility should discuss alternative treatments with their healthcare provider, such as human chorionic gonadotropin (hCG) or selective estrogen receptor modulators (SERMs), which can help maintain testosterone levels without significantly impacting sperm production, as suggested in the guideline 1.
- For men with hypogonadotropic hypogonadism, treatment with exogenous gonadotropins or pulsatile GnRH can initiate and maintain spermatogenesis, and referral to an endocrinologist or male reproductive specialist is recommended 1.
Overall, the potential negative impact of testosterone supplementation on sperm count and fertility is a critical consideration for men who may want to have children in the future, and alternative treatments should be explored under the guidance of a healthcare provider.
From the Research
Testosterone Supplementation and Sperm Count
- Testosterone supplementation can have a negative effect on sperm count, as it suppresses the production of gonadotropin and sperm production 2.
- Chronic testosterone administration in physiological to moderately supraphysiological dosages results in parallel dose-dependent suppression of LH, FSH, and sperm production 2.
- However, some studies suggest that certain medications, such as clomiphene citrate, can improve testosterone levels and sperm concentration in infertile men with low testosterone levels and normal or low gonadotropines levels 3, 4.
Effects of Testosterone Supplementation on Sperm Production
- Exogenous testosterone supplementation decreases sperm production, representing a problem for hypogonadal men of reproductive age 5.
- Studies of hormonal contraception indicate that most men have a return of normal sperm production within 1 year after discontinuation of exogenous testosterone supplementation 5.
- Clomiphene citrate is a safe and effective therapy for men who desire to maintain future potential fertility, as it improves testosterone production and sperm concentration 3, 4, 5.
In Vitro Effects of Clomiphene Citrate on Sperm Parameters
- Clomiphene citrate can improve sperm parameters, including viability, morphology, and motility, in vitro 6.
- The application of clomiphene citrate in the culture medium may improve sperm parameters in IVF protocol with no side effects 6.
- However, the optimal dosage and treatment duration of clomiphene citrate for improving sperm parameters and fertilization rate are still unclear and require further research 6.