Short answer: Suvorexant (Belsomra) is a sleep medicine that blocks orexin, a brain chemical that keeps you awake, rather than boosting GABA like benzodiazepines and Z-drugs. It is a Schedule IV controlled substance, but studies show little withdrawal when it is stopped.
Key takeaways
- What it is: Suvorexant is an orexin receptor antagonist and a Schedule IV controlled substance in the US.
- Main uses: Insomnia.
- Timing: effects start in about 30 minutes and last 7 hours or more.
- Most dangerous mix: Alcohol, which can cause additive impairment.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: Low.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is suvorexant?
Suvorexant is approved for insomnia with difficulty falling asleep or staying asleep.
Orexins are brain chemicals that promote wakefulness. By blocking their receptors, suvorexant helps switch off wake signals. Similar medicines include lemborexant (Dayvigo) and daridorexant (Quviviq).
Quick facts
| Fact | Suvorexant |
|---|---|
| Generic name | Suvorexant |
| Brand names | Belsomra |
| Drug class | Dual orexin receptor antagonist |
| US legal status | Schedule IV, prescription only |
| Approved uses | Insomnia (sleep onset and maintenance) |
| Forms | Tablets |
| Onset | About 30 minutes |
| Half-life | About 12 hours |
| Broken down by | CYP3A4 |
How long does suvorexant last?
- Starts working: About 30 minutes
- Effects last: 7 hours or more
- Half-life: About 12 hours
Timing varies with the dose, the form, how it is taken, liver and kidney function, age, and other drugs taken at the same time.
What are the biggest risks of suvorexant?
Common side effects include next-day drowsiness, headache, dizziness, and abnormal dreams.
Other risks include next-day impairment of driving at 20 mg, sleep paralysis, hallucinations when falling asleep or waking, cataplexy-like muscle weakness, complex sleep behaviors, and worsening depression.
What should you never mix with suvorexant?
| Combined with | What happens | Label guidance |
|---|---|---|
| Alcohol | Additive impairment | Avoid |
| Opioids, benzodiazepines, other sedatives | Additive sedation | Use caution |
| Ketoconazole, clarithromycin, ritonavir | Sharply raise suvorexant levels | Not recommended |
| Rifampin, carbamazepine | Lower suvorexant levels | Reduced effect |
| Digoxin | Slightly raises digoxin levels | Monitor |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a suvorexant overdose, and what should you do?
Experience with overdose is limited. High doses cause dose-related sleepiness. Combined with alcohol or other sedatives the effects are harder to predict.
If someone may have overdosed
- Call 911 if the person is unresponsive, hard to wake, or breathing slowly.
- For advice when the person is awake and stable, call Poison Help at 1-800-222-1222 (US, free, 24 hours).
- If opioids could be involved, including pills not from a pharmacy, give naloxone if you have it. Naloxone does not reverse suvorexant, but it will not harm the person.
- Stay with the person and place them on their side if they are drowsy or vomiting.
Does suvorexant cause withdrawal?
In clinical trials, stopping suvorexant after up to a year of use did not cause withdrawal symptoms or significant rebound insomnia. It is Schedule IV because high doses produced drug-liking similar to zolpidem in people who misuse sedatives.
- Nights 1 to 3Sleep may be lighterSome people notice a return of their original insomnia.
- Week 1No typical withdrawalTrials showed no withdrawal syndrome.
- OngoingUnderlying insomniaCBT-I treats the cause long-term.
See the withdrawal timelines and the full suvorexant withdrawal guide.
Is suvorexant legal?
In the United States, suvorexant is a Schedule IV controlled substance. The only legal way to get it is with a prescription from a clinician registered with the Drug Enforcement Administration (DEA), filled by a licensed pharmacy. Depending on state law, that can be a physician, nurse practitioner, or physician assistant.
- Refills: a Schedule IV prescription can be refilled up to five times within six months of the date it was written. After that, a new prescription is needed.
- Telehealth: federal flexibilities let DEA-registered clinicians prescribe Schedule II to V medicines after a telemedicine visit, without a prior in-person exam, through December 31, 2026. A permanent DEA rule was under final review in late 2026. State rules can be stricter.
- Monitoring: prescribers and pharmacists in most states check a prescription drug monitoring program, a database of controlled-substance prescriptions, before prescribing or dispensing.
Outside the United States
| Country | Status |
|---|---|
| Japan | Approved prescription medicine |
| Australia | Schedule 4 prescription medicine |
| International | Not under UN control |
Frequently asked questions about suvorexant
How is Belsomra different from Ambien?
Belsomra blocks wake-promoting orexin signals, while Ambien enhances GABA. Belsomra has a lower risk of dependence and withdrawal.
Is suvorexant addictive?
It has a low risk of dependence, but it is Schedule IV because people who misuse sedatives liked high doses in studies.
Who should not take suvorexant?
People with narcolepsy should not take it, because it blocks the same system that is missing in narcolepsy.
Sources
- Belsomra (suvorexant) prescribing information, DailyMed, US National Library of Medicine.
- Controlled Substance Schedules, DEA Diversion Control Division.
- 21 CFR 1306.22, Refilling of prescriptions (Schedules III and IV), Electronic Code of Federal Regulations.
- Prescribing controlled substances via telehealth, US Department of Health and Human Services.
- BeSafeRx: Your Source for Online Pharmacy Information, US Food and Drug Administration.
- Safe Pharmacy, National Association of Boards of Pharmacy.
- One Pill Can Kill, US Drug Enforcement Administration.
- International drug control conventions, United Nations Office on Drugs and Crime.
This guide summarizes the sourced DoseUses Suvorexant profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
