It is well established that morphine and other opioid drugs in both men and women exert a pronounced effect on the gonads, causing hypogonadotroph hypogonadism. The thyroid function seems unimpaired. Only a small number of studies have addressed the effects of opioids on the adrenocortical function. They strongly suggest that opioids may cause adrenocortical insufficiency - even presenting as severe and life-threatening hypoadrenalism. At present a substantial number of patients are on long-term treatment with opioids, making the above findings relevant in daily clinical practice.