MDMA generally increases sexual desire and intensifies orgasm when achieved, but its effects on arousal are mixed and it may impair erectile and ejaculatory function in men. A systematic review of 6 studies on women and 8 on men found that 4 of 6 studies reported increased sexual desire in women, while 60% of interview-based studies reported increased desire in men. Arousal and lubrication improved in 3 of 4 studies on women. All studies on orgasm reported a delay in achieving it but greater intensity and pleasure. Evidence on sexual arousal was conflicting for both sexes.
Recreational psychostimulants produce inconsistent sexual effects in women. Amphetamine and methamphetamine generally enhance sexual function, but studies are small. MDMA may either increase or decrease sexual activity while often enhancing sensual aspects. Low doses of cocaine can heighten sexual experience, but most women report negative effects. Caffeine increases vaginal blood flow, but subjective sexual effects have not been studied. More research is needed to understand these varying effects.