BackgroundIncreased prevalent use of methamphetamine is a global public challenge. Information on drug use can be helpful in preventing high-risk behavior related to drug abuse.ObjectivesThis study aims to investigate the sexual function changes related to methamphetamine use in the male clients of public and private addiction treatment centers.Patients and MethodsIn this qualitative study, 45 men (35 methamphetamine users, 5 family members of the users, and 5 psychiatrists or physicians who were famous for treating or researching addiction) are involved. An in-depth interview was done with therapists and key individuals.ResultsThe results show that the effects of methamphetamine on sexual function are not identical. The first usage is concomitant with the increased duration of sex, an increase in the quality and quantity of sexual pleasure, a delighted orgasm, and feeling more control of the sex act. These effects gradually decrease. A decreased libido and various sexual dysfunctions such as erectile dysfunction, premature ejaculation, and losing control during the sex act will appear over time.ConclusionsThere are differences in the libido and sexual functions of methamphetamine users. Personal perceptions of one’s sexual function may be affected by cognitive changes resultant from the drug. Drug-use prevention, addiction treatments, appropriate sexual behavior education, and harm reduction are priorities.