Naturally occurring opiates (endorphins) diminish testosterone levels by inhibiting both hypothalamic gonadotrophin releasing hormone production and testicular testosterone synthesis. (jeffreydachmd.com)
Beckers, N. G., Laven, J. S., Eijkemans, M. J., and Fauser, B. C. Follicular and luteal phase characteristics following early cessation of gonadotrophin - releasing hormone agonist during ovarian stimulation for in - vitro fertilization. (webmd.com)
Too little luteinizing hormone stops ovulation in women or creates a deficiency in gonadotrophin - releasing hormone (GnRH) secretion in men. (hormone.org)