The main aim of this study is to determine the effects of Parsnip syrup (a product based on Persian carrot and composed from anise, honey, saffron, dianthus, Green cardamom and Nardosthacys Jatamansi) on sexual function of female multiple sclerosis (MS) patients. Practical purpose of it is to introduce an effective drug with low side effects for treatment of sexual disturbance based on Iranian traditional medicine. Type of study is third phase of triple-blinded randomized clinical trial, one central and controlled with placebo. The study population is selected randomly from the MS patients who referred to traditional medicine clinics of Tehran University of Medical Sciences having sexual disturbance complaint, after filling consent form. The sample size in each group is 34 people. Group A & B Receiving Parsnip syrup or placebo twice a day each time 10 cc respectively. Inclusion criteria: sexually active married female, 18 - 50 years old, definite MS patients, not been in a new attack during the intervention period or recent month. Exclusion criteria: Severe depression, pregnancy, history of skin allergy to Apiaceae family, taking drug for sexual disturbance or anticoagulants, starting the disease modifying drugs within the recent 3 months or suffering from diabetes mellitus. Intervention duration is from Day 1395 to Day 1396 (December 2016- December 2017). Based on valid Persian forms of Multiple Sclerosis Intimacy and Sexuality Questionnaire-19 [MSISQ-19] and Female Sexual Function Index (FSFI) questionnaires sexual disturbances severity will be determined before and after the intervention and possible side effects will be recorded.