Clinical experience with gossypol in non-Chinese men: a follow-up.

Gossypol monoacetic acid was administered to 12 Brazilian volunteers. The initial dose was 20 mg daily for 4 months. The dose was then reduced to 60 mg weekly (20 mg three times weekly). A significant reduction in sperm motility was detected in all subjects. An increase in the number of immature cells in the ejaculate was also detected in all subjects. Severe oligospermia or azoospermia developed in all subjects at the end of the loading phase. Two years following discontinuation, 3 men were still azoospermic. Only 1 man who was azoospermic 2 years after discontinuation had a late (3 years) recovery. Two of the 3 men who were subjected to high spermatic vein ligation because of varicocele remained azoospermic 2 years after the operation. The third patient, who did not have the operation, also remained azoospermic. Of the 9 patients who recovered, 3 had fathered children during the last 2 years.