Antioxidant supplement NAC tested for MS brain health

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Clinical diagnosis of relapsing remitting MS or progressive MS who do not plan to start a medication during the study, or on stable disease modifying medication (interferon, glatiramer, dimethyl fumarate, teriflunomide). * Age 18 years old to no upper limit * Physically independent, ambulatory * Women of childbearing potential will confirm a negative pregnancy test and must practice effective contraception during the period of pilot study. In addition, male subjects who have a partner of childbearing age should practice effective contraception. * Participants must be able to complete study procedures in the greater Philadelphia area. Exclusion Criteria: * Patients are excluded who have received treatment with intravenous steroids within the past 90 days for reasons other than MS * Previous brain surgery that would interfere with determination of cerebral metabolism or structure on the FDG PET-MRI. * Score on Mini-Mental Status examination of 20 or lower. * Wheelchair-bound or bed-ridden, non-ambulatory. * Intracranial abnormalities that may complicate interpretation of the brain scans (e.g., stroke, tumor, vascular abnormality affecting the target area). * History of head trauma with loss of consciousness \> 48 hours. * History of asthma requiring daily medications for adequate management. * Any medical disorder or physical condition that could reasonably be expected to interfere with the assessment of MS symptoms, or with any of the study assessments including the PET-MRI imaging. * Patients with evidence of a significant psychiatric disorder by history/examination that would prevent completion of the study will not be allowed to participate. * Patients with current alcohol or drug abuse * Pregnant or lactating women. * Enrollment in active clinical trial/ experimental therapy within the prior 30 days. * Pending surgery during the course of the study. * Patients taking medications that might interact with NAC involved in this study will be evaluated on a case by case basis by the PI or study physician. These medications include: Medications for high blood pressure; Medications that slow blood clotting; Medications for diabetes; Nitroglycerin. * Patients with history of pulmonary hypertension. * Any neurological, psychiatric, or medical condition that might affect the distribution of the radiopharmaceutical in the body or brain (as determined by Investigator) * Currently using medications that might alter the distribution of radiopharmaceuticals in - -the body or brain (as determined by Investigator) * Patient exceeds the weight limit of the table * Claustrophobia that would prevent completion of imaging studies * Glucose level that would interfere with the FDG PET scan * Any additional contraindications for MRI; Has metallic objects (e.g., pacemakers) in the body