 This is a phase IV single-blind, placebo run-in fixed dose single-group study to assess objective and subjective effects of GEn on sleep EEG, BP, and anterior tibialis EMG responsivity in patients with RLS. The study will include 8 visits over a period of up to 8 weeks for eligible subjects including a 1 to 3-week ScreeningWashout Period, a 1-week placebo run-in period, and a 4-week Treatment Period.The first placebo dose will be administered within 1 to 3 weeks after ScreeningWashout. The total duration of the study from the first subject enrolled to the last subject completed will be approximately 1 year. 