Tasimelteon is a medication primarily used to treat non-24-hour sleep-wake disorder, a condition often affecting individuals who are blind. It works by mimicking the action of melatonin, a hormone that regulates sleep-wake cycles, helping to promote sleep at appropriate times. This drug is taken orally, usually before bedtime, and is designed to help improve sleep quality and duration. Clinical studies have shown that tasimelteon can be effective in reducing insomnia symptoms associated with this disorder, allowing individuals to better align their sleep patterns with the day-night cycle.