The importance of understanding baseline reproductive function prior to the administration of exogenous testosterone

Recent increases in the awareness of hypogonadism as a clinical condition have led to more men being managed with testosterone supplementation therapy （TST）. While highly effective at raising serum testosterone levels and controlling the symptoms of hypogonadism such as fatigue and low energy,1 the resultant suppression of the hypothalamic-pituitary-gonadal axis can lead to an inhibition of gonadotropins, including follicle-stimulating hormone （FSH） and luteinizing hormone （LH） and subsequent azoospermia.