After intensified economic sanctions against Iran, decreased welfare of patients were more recognizable. The present study was aimed at identifying the challenges and stress level experienced by patients with multiple sclerosis (MS) regarding treatment and health care services in 2018-2019 after strengthening of economic sanctions against Iran. A cross-sectional study was conducted on MS patients in Tehran, Iran. A structured questionnaire was designed to measure the main variables addressing the challenges and stress level of MS patients with respect to receiving care and treatment services. In total, 1039 MS patients were enrolled into the study. Among the patients who answered yes to the questions, 873 (85.8%) and 837 (86%) were concerned about medicine unavailability and supply and purchase of internationally branded medicine, respectively. Moreover, 671 (70.3%) subjects were concerned about replacing their medicines with cheaper alternatives due to financial problems and 427 (41.4%) were unwilling to continue their treatment due to the economic burden of MS. In total, 795 (82%) were concerned about the effectiveness of Iranian drugs in comparison with internationally branded drugs. Generally, 970 (93.53%) subjects had experienced increased current living costs and 711 had experienced (68.82%) reduced nutrition quality, which (OR: 2.68; 95% CI: 1.99, 3.60) was significantly higher among subjects who had an income of less than or equal to 250 US$ per month. The sanctions can impose greater stress and hardship on patients due to the unavailability and costs of medicines. Iran should manage health care quality and provide services to prevent the adverse effects of sanctions on MS patients and guarantee patients' right to receive well-established medication and health services.