Premature ejaculation (PE) is ejaculation occurring without control, on or shortly after vaginal penetration and before the subject wishes it, causing marked distress or interpersonal difficulties. PE is the most common male sexual complaint. Primary (lifelong) PE has a physiological basis. Therapy should involve the man and his partner. The primary aims of therapy are for the man to regain a sense of control over his ejaculation time and for him and his partner to feel satisfaction with sexual intercourse. The most effective therapies for primary PE are certain selective serotonin reuptake inhibitors, given on a daily basis or "on demand" before sexual activity. Topical anaesthetics have also been shown to be effective. The most common cause of secondary PE is declining erectile function. The approach to treating secondary PE is to treat the underlying condition.