Secondary outcomes will be improvement in other cognitive tests, brain MRIs, cognitive evoked potentials, as well as relapse rates and disability measures (EDSS, 25 foot walk, 9 hole peg test, low contrast visual acuity, MS Quality of Life, Modified Fatigue Impact Scale, Beck Depression Inventory, Level of Activity using accelerometry). Safety measures (blood tests and gynecologic evaluations) will also be followed. The overall goal of this study will be the development of an oral treatment, estriol, to improve cognitive function in MS.