There is no serious risk from acute poisoning, but chronic use can cause harm. The main risks are those of excessive androgens: menstrual irregularities and virilization in women and impotence, premature cardiovascular disease and prostatic hypertrophy in men. Both men and women can suffer liver damage with oral anabolic steroids containing a substituted 17-alpha-carbon. Psychiatric changes can occur during use or after cessation of these agents. Acute overdosage can produce nausea and gastrointestinal upset. Chronic usage is thought to cause an increase in muscle bulk, and can cause an exageration of male characteristics and effects related to male hormones. Anabolic steroids can influence sexual function. They can also cause cardiovascular and hepatic damage. Acne and male- pattern baldness occur in both sexes; irregular menses, atrophy of the breasts, and clitoromegaly in women; and testicular atrophy and prostatic hypertrophy in men.