Tasimelteon
Tasimelteon is a melatonin receptor agonist used to treat Non-24-Hour Sleep-Wake Disorder, a condition where individuals cannot align their circadian rhythm with the standard 24-hour day, most commonly affecting blind people. It works by activating melatonin MT1 and MT2 receptors to help regulate the body's internal sleep-wake cycle.
Tasimelteon is a melatonin agonist used to treat Non-24-Hour Sleep-Wake Disorder by helping regulate circadian rhythms in blind individuals.
Key facts at a glance
- ATC
- N05CH03
- RxNorm
- 1490468
- Generic
- Tasimelteon
- Class
- atc-n05
- Brands
- Hetlioz
- Availability
- rx
- Lactation
- unknown
- Routes
- oral
- Forms
- capsule, suspension
- Regions
- US, EU, CN, JP
- Monitoring
- —
This page is for informational purposes only.
Do not use this information to diagnose yourself or to replace a physician's advice. Always consult a qualified healthcare provider before starting, stopping, or changing any medication. If you believe you are experiencing a medical emergency, call your local emergency number immediately.
Non-24-Hour Sleep-Wake Disorder (Non-24), a circadian rhythm sleep disorder most common in completely blind individuals who lack light perception and cannot synchronize their sleep-wake cycle with the 24-hour day.
Tasimelteon is a selective agonist at melatonin MT1 and MT2 receptors, which are involved in controlling circadian rhythms, sleep onset, and the regulation of the sleep-wake cycle. By activating these receptors, it helps establish a more regular pattern of sleepiness and wakefulness.
Should be taken once daily at the same time before bedtime. The most common side effects include headache, somnolence, and nasopharyngitis. Efficacy and safety have been primarily studied in blind populations. Patients should avoid activities requiring alertness shortly after taking the medication.
Official drug label
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This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed July 26, 2026. · Read our editorial policy