Twenty-one single oral doses of 1-octanol were given to patients with essential tremor (ET) in an open-label dose-escalation study. The drug was well tolerated up to 64 mg/kg. The main side effect was an unusual taste. No overt intoxication was seen. There was evidence for efficacy, with a significant reduction in tremor amplitude as measured by accelerometry and handwriting that was maximal at 2 hours. Higher doses may produce more sustained benefit.