Essential tremor (ET) is a slowly progressive, chronic neurological disorder characterized by a 4- to 12-Hertz tremor, which can involve the arms, head, voice and lower extremities. Although the hallmark of the disorder is thought to be the kinetic tremor, ET patients usually also manifest a postural tremor as well. Kinetic tremor (tremor with voluntary movements) may interfere with fine motor skills (e.g., writing, eating, drinking from a cup, pouring liquids); and depending upon its severity, may result in significant disability and diminished quality of daily living. Essential tremor represents an area of unmet medical need and this study is designed as a safety, tolerability and proof-of-concept investigation of the ability of ST101 to improve tremor. In this 2-stage study, subjects will be randomly assigned to either ST101 or placebo in Stage 1, and will receive the alternate treatment in Stage 2.