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Tasimelteon Dosage

Medically reviewed by Last updated on Nov 4, 2019.

Applies to the following strengths: 20 mg

Usual Adult Dose for:

Additional dosage information:

Usual Adult Dose for Insomnia

20 mg orally once per day

-Take before bedtime, at the same time every night.
-Take without food.

Use: Treatment of Non-24-Hour Sleep-Wake Disorder (Non-24)

Renal Dose Adjustments

No adjustment recommended

Liver Dose Adjustments

-Mild liver impairment (Child-Pugh 5 to 6): No adjustment recommended.
-Moderate liver impairment (Child-Pugh 7 to 9): No adjustment recommended.
-Severe liver impairment (Child-Pugh C): Not recommended.


Safety and efficacy have not been established in patients younger than 18 years.

Consult WARNINGS section for additional precautions.


This drug is dialyzable; however, no dose adjustment guidelines have been reported.

Other Comments

Administration advice:
-When this drug cannot be taken at approximately the same time on a given night, skip the dose that evening and return to the normal dose schedule the following night.
-Swallow drug capsule whole; do not chew, break, or crush.

Storage requirements:
-Protect from light and moisture.
-Store at room temperature (25 degrees Celsius/77 degrees Fahrenheit); excursions permitted to 15 to 30 degrees Celsius (59 to 86 degrees Fahrenheit).

-There is not any evidence showing this drug has potential for abuse or physical dependence.
-For overdosage, general symptomatic and supportive measures should be used along with immediate gastric lavage and IV fluids where appropriate. It is not known if hemodialysis will effectively reduce exposure in overdose cases.

Patient advice:
-After taking this drug at night, only do activities needed to get ready for bed since this drug may cause you to feel drowsy and less mentally alert.
-Do not smoke while taking this drug as it may reduce the drug's effectiveness.
-Avoid drinking alcohol while taking this drug as it may slow your actions.
-It may take several weeks or months for you to notice any benefit from this drug due to the individual differences in circadian rhythms.
-Do not take 2 doses of this drug at the same time or extra doses. If you skip a dose, return to your normal dose schedule the next night.
-Do not store this drug in the bathroom; protect it from moisture and light.

Further information

Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.