Description: This study will compare different doses of the study drug with a non-medicinal placebo in people with relapsing remitting multiple sclerosis (RRMS). Candidates 18-55 may be included who have RRMS with at least one relapse in the last year or two relapses in last two years. Participants also must be able to walk 100 yards without assistance. Volunteers with diabetes or low heart rate are ineligible