Meth And Sexual Behavior:
Main article: Methamphetamine and sex
Users may exhibit sexually compulsive behaviour while under the influence. This disregard for the potential dangers of unprotected sex or other reckless sexual behavior may contribute to the spread of sexually transmitted infections (STIs) or sexually transmitted diseases (STDs). Among the effects reported by methamphetamine users are increased libido and sexual pleasure, the ability to have sex for extended periods of time, and an inability to ejaculate or reach orgasm or physical release. In addition to increasing the need for sex and enabling the user to engage in prolonged sexual activity, methamphetamine lowers inhibitions and may cause users to behave recklessly or to become forgetful. Users may even report negative experiences after prolonged use, which contradict reported feelings, thoughts, and attitudes achieved at similar dosages under similar circumstances but at earlier periods of an extended or prolonged cycle. Additionally, many chronic users find themselves engaging in excessive and repeated masturbation. According to a recent San Diego study , methamphetamine users often engage in unsafe sexual activities, and forget or choose not to use condoms. The study found that methamphetamine users were six times less likely to use condoms. The urgency for sex combined with the inability to achieve release (ejaculation) can result in tearing, chafing, and trauma (such as rawness and friction sores) to the sex organs, the rectum and mouth, dramatically increasing the risk of transmission of HIV and other sexually transmitted diseases. Methamphetamine also causes erectile dysfunction due to vasoconstriction.