By Naomi Carr

Last updated: 10 May 2024 & medically reviewed by Morgan Blair

Suvorexant (Belsomra) is a sedating medication used to treat insomnia. It can cause side effects such as drowsiness and dizziness and may cause adverse effects if it is taken in combination with other substances or prescribed medications. It is important to always follow medical advice and take medications as prescribed.

Suvorexant (Belsomra)

What is suvorexant (Belsomra)?

Suvorexant is a sedative-hypnotic medication sold under the brand name Belsomra. It is used to treat insomnia and helps individuals with falling and staying asleep.[1]

Suvorexant (Belsomra) is an orexin receptor antagonist. It works by blocking certain activity and chemical reactions in the brain to suppress wakefulness.[2]

Suvorexant (Belsomra) is available as a tablet, in 5mg, 10mg, 15mg, and 20mg strengths.[1]

In what dose should Belsomra be taken?

Belsomra should be taken at the lowest effective dose. This will vary from person to person and should be reviewed and adjusted as necessary. Typically, individuals will start with a 10mg dose, which can be increased to 15mg or 20mg. The daily dose should not be increased above 20mg.[1]

Belsomra is taken in one dose, 30 minutes before going to bed. It is recommended to only take this medication when it is possible to remain in bed for at least seven hours following administration.[3]

Belsomra can be taken with food or on an empty stomach. It can take longer for the effects to be felt if it is taken with food.[1]

If insomnia symptoms worsen or do not improve within 7-10 days of Belsomra use, inform the prescribing doctor. This may indicate an underlying physical or mental health condition.[1]

Side effects of Belsomra

When taking a new medication, it is common for side effects to occur. Typically, these side effects will be mild and will be alleviated within a short time. Side effects of Belsomra may be more common in individuals who are obese, female, or of an older age.[1]

Common side effects of Belsomra include:[1][3]

  • Drowsiness

  • Daytime sleepiness

  • Headache

  • Unusual or vivid dreams

  • Coughing

  • Dry mouth

  • Dizziness

  • Diarrhea

Some people may experience severe side effects. If any side effects occur that do not go away or become problematic, it is recommended to contact a medical professional immediately. 

Rare or serious side effects of Belsomra can include:[1][2][4]

  • Complex sleep behaviors: Some individuals taking Belsomra engage in activities while they are not completely awake, such as driving or preparing food. Often, they are not aware of or cannot remember having engaged in these actions. This can cause an increased risk of accidental harm.

  • Sleep paralysis: Some individuals may experience sleep paralysis, involving an inability to move the body within the first few minutes of awakening or experiencing troubling or vivid hallucinations and perceptions.

  • Temporary weakness: Some people may experience sudden temporary weakness in their legs, during the day or night.

  • Extreme change in mental state: Belsomra can sometimes contribute to the onset of symptoms such as aggression, mania, depression, anxiety, hallucinations, or dissociation.

Belsomra drug interactions

Belsomra can interact with other substances and medications. This can cause a reduction in the effects of medications or an increased risk of side effects. 

Central nervous system (CNS) depressants can interact with Belsomra to cause an increase in sedating effects, slowed or impaired movements, and increased risks of heart or breathing difficulties. CNS depressants include opioids, benzodiazepines, and alcohol.[1]

Other medications that can interact with Belsomra include some antifungals, antivirals, antibiotics, antiemetics, anticonvulsants, anxiolytics, antidepressants, analgesics, chemotherapy medications, sedatives, tranquilizers, sleeping pills, and medications for heart conditions.[1][3]

It is important to inform the prescribing doctor of all medications and substances being used before starting a new treatment. It may be necessary to take an altered dose or alternative medications and to ensure careful monitoring.

Is Belsomra addictive?

Studies show that there is a small risk of Belsomra causing abuse and addiction. The risk of abuse and addiction is likely to be increased if the medication is used for a prolonged period or in higher doses than prescribed.[1][5]

Belsomra is unlikely to cause effects such as euphoria, which contributes to an abuse potential and the development of an addiction.[5] 

However, because of its sedating effects, some individuals may be at risk of misuse or abuse, particularly those with a history of alcohol or substance use disorders. If Belsomra is deemed necessary for treatment in these individuals, it may be necessary to closely monitor their use and side effects.[1]

Does Belsomra cause weight loss?

There is no evidence that Belsomra causes weight loss or weight gain.[4]

Individuals with insomnia or underlying mental and physical health conditions may experience changes in their appetite and calorie consumption following treatment. However, this is unlikely to occur as a direct result of the medication. 

Is Belsomra a controlled substance?

Belsomra is classified as a Schedule IV controlled substance. This means that it has a clear but low potential for abuse, dependence, and addiction. Controlled substances can only be obtained through a prescription, which can be filled a limited number of times.[3][6]

Staying safe on Belsomra

Health conditions

Some individuals may not be able to safely take Belsomra. This includes people with certain physical health conditions, such as narcolepsy, liver disease, sudden muscle weakness, or obesity.[3]

Taking Belsomra with pre-existing respiratory conditions, such as COPD or sleep apnea, may cause an exacerbation of symptoms. Individuals with these conditions should be closely monitored throughout treatment.[1]

Pregnancy and breastfeeding

Evidence of the safety of Belsomra during pregnancy or breastfeeding is limited. It is recommended to consult with the prescribing clinician before starting Belsomra so they can advise on appropriate treatments. Belsomra may cause some risk of harm to the fetus or breastfeeding infant so close monitoring will be required.[1]

Medication use

Belsomra should be used exactly as prescribed. Doses should be taken 30 minutes before going to bed. Additionally, individuals should not take Belsomra if they are unable to remain in bed for the following seven hours.[3]

Taking Belsomra during the day or when unable to remain in bed can increase the risk of adverse effects or accidental harm caused by sedation.[2]

Taking larger doses than have been prescribed can increase the risk of side effects and addiction potential.[1]


Belsomra can cause drowsiness that lasts until the following day. It is advised not to drive or operate heavy machinery while taking Belsomra, particularly within eight hours of the last dose.[1]

Older adults may be at an increased risk of dizziness and falls when taking Belsomra, so caution is advised.[3]

Always take Belsomra exactly as prescribed. Never take more than is prescribed or give the medication to others, as this can increase the risk of adverse effects. 

It is recommended not to drink alcohol while taking Belsomra.[1]