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Belsomra Side Effects

Generic name: suvorexant

Medically reviewed by Philip Thornton, DipPharm. Last updated on Nov 14, 2023.

Note: This document contains side effect information about suvorexant. Some dosage forms listed on this page may not apply to the brand name Belsomra.

Applies to suvorexant: oral tablet.

Serious side effects of Belsomra

Along with its needed effects, suvorexant (the active ingredient contained in Belsomra) may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking suvorexant:

More common

Less common

Incidence not known

Other side effects of Belsomra

Some side effects of suvorexant may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common

Less common

For Healthcare Professionals

Applies to suvorexant: oral tablet.


The most common adverse reaction was somnolence.[Ref]


Common (1% to 10%): Diarrhea, dry mouth[Ref]

Nervous system

Common (1% to 10%): Headache, somnolence, dizziness[Ref]


Common (1% to 10%): Abnormal dreams[Ref]


Common (1% to 10%): Cough, upper respiratory tract infection[Ref]


1. Product Information. Belsomra (suvorexant). Merck & Co., Inc. 2014.

Further information

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

Some side effects may not be reported. You may report them to the FDA.