This study will be done to compare the impact of Ginseng and placebo on sexual performance status in men and women treated with methadone. The present research is a double blind clinical trial. The study sample population is consist of all men and women drug addicts referring to Methadone Maintenance Treatment Centers in Kermanshah, which 70 of them will be selected by census method, and will be categorized into control and experiment. The subjects of both groups will be matched in terms of age and Sex, and the FSFI sexual dysfunction questionnaire for women and international index of erectile dysfunction (IIEF) will be distributed among them. In the experimental group, the participants will receive daily four capsules of Ginseng, while the control group will receive four placebo capsules daily. The questionnaire will be re-distributed among both groups at the first and at the end of the study (4 weeks after the start of the study), and the sexual function in men and women will be measured. Inclusion criteria: patients undergoing methadone treatment; married; age between 18-50 years; lack of sexual problems before treatment with methadone. Exclusion criteria: Under age of 18, drugs that positive and negative affect on sexual performance, recent use any other drugs or alcohol, spinal cord injury, radical prostatectomy, singular, the existence of recent mental disorder, recent communication disorder with wife, allergy to Ginseng.