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 fatigue of multiple sclerosis (MS) patients. The practical purpose of it is to introduce an effective drug with low side effects for treatment of fatigue based on Iranian traditional medicine. Type of the study is the 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 fatigue complaint, after filling consent form. The sample size in each group is 48 people. Group A & B Receiving Parsnip syrup or placebo twice a day each time 10 cc respectively. Inclusion criteria:18 - 50 years old, definite MS patients, not been in a new attack during the intervention period or the recent month. Exclusion criteria: Severe depression, pregnancy, history of skin allergy to Apiaceae family, taking drug for depression or fatigue or anticoagulant drugs, starting the disease modifying drugs within the recent 3 months or suffering from diabetes mellitus. Intervention duration is from Khordad 1395 to Khordad 1396 (May 2016- May 2017). Based on valid Persian forms of Fatigue Severity Scale (FSS), Modified Fatigue Impact Scale (MFIS) and Analogue visual scale (VAS) questionnaires fatigue severity will be determined before and after the intervention and possible side effects will be recorded.