Serum-testosterone during oral administration of testosterone in hypogonadal men and transsexual women.

Testosterone tablets of crystal size 2-5 micrometer were administered orally for 10 dags to 3 human subjects with low endogenous serum testosterone (se-T) levels. Fifty mg testosterone increased se-T slightly, while one daily dose of 200 mg maintained the se-T level within normal range for men for more than 12h. No cumulative effect was seen. Seven further subjects with low androgen production ingested 100 or 200 mg testosterone of crystal size 125-400 micrometer. Blood samples were taken frequently during the 24 h period following administration of the testosterone and se-T levels determined. Testosterone levels in serum increased in 6 patients and was maintained within the normal male range for 5-7 h. In one subject a slight but significant increase in se-T was observed although the level did not reach the normal male range. Although it has been shown that it is possible to use orally administered testosterone to maintain se-T levels in the normal male range, the convenience to the patient must be balanced against the cost and possible side effects of the large doses required.