Is Testosteron useful for fertility?

Testosterone is crucial for male fertility, driving spermatogenesis (sperm production). However, the relationship is not linear: low testosterone can impair fertility, while exogenous testosterone (e.g., supplements) often suppresses the hypothalamic-pituitary-gonadal axis, reducing sperm count. Thus, testosterone is not universally 'useful' for fertility; it must be within a physiological range. For men trying to conceive, medical evaluation including hormone levels and semen analysis is recommended. Evidence is based on strong clinical consensus, though individual variation exists.