Short answer: Carisoprodol (Soma) is a muscle relaxant for short-term relief of acute, painful muscle conditions, used for no more than two or three weeks. The body converts it to meprobamate, an older sedative. It became a federal Schedule IV controlled substance in 2012 because of misuse.
Key takeaways
- What it is: Carisoprodol is a centrally acting muscle relaxant and a Schedule IV controlled substance in the US.
- Main uses: Acute muscle pain (short-term).
- Timing: effects start in about 30 minutes and last 4 to 6 hours.
- Most dangerous mix: Opioids and benzodiazepines, which can cause profound sedation and slowed breathing; overdose deaths.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: Moderate.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is carisoprodol?
Carisoprodol is approved for relief of discomfort from acute, painful musculoskeletal conditions in adults, for up to two or three weeks, alongside rest and physical therapy.
Its sedating effects come largely from its metabolite meprobamate, a barbiturate-like anti-anxiety drug from the 1950s. Most guidelines recommend other muscle relaxants or non-drug treatment first.
Quick facts
| Fact | Carisoprodol |
|---|---|
| Generic name | Carisoprodol |
| Brand names | Soma |
| Drug class | Centrally acting skeletal muscle relaxant |
| US legal status | Schedule IV, prescription only (since 2012) |
| Approved uses | Acute, painful musculoskeletal conditions, short-term |
| Forms | Tablets |
| Onset | About 30 minutes |
| Half-life | About 2 hours; meprobamate about 10 hours |
| Broken down by | CYP2C19 to meprobamate |
How long does carisoprodol last?
- Starts working: About 30 minutes
- Effects last: 4 to 6 hours
- Half-life: About 2 hours; meprobamate about 10 hours
Only two to three weeks. Muscle problems lasting longer need other treatment.
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 carisoprodol?
Common side effects include drowsiness, dizziness, and headache.
Serious risks include dependence, withdrawal, seizures, and misuse. Combined with opioids and benzodiazepines, a combination sometimes called the "holy trinity", carisoprodol has been involved in many overdose deaths.
What should you never mix with carisoprodol?
| Combined with | What happens | Label guidance |
|---|---|---|
| Opioids and benzodiazepines | Profound sedation and slowed breathing; overdose deaths | Avoid |
| Alcohol | Additive sedation | Avoid |
| Omeprazole, fluvoxamine (CYP2C19 inhibitors) | Raise carisoprodol levels | Use caution |
| Rifampin, St. John's wort | Lower carisoprodol levels | May reduce effect |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a carisoprodol overdose, and what should you do?
Carisoprodol overdose causes stupor, coma, shock, seizures, slowed breathing, and abnormal muscle movements. It is often fatal when combined with opioids or alcohol.
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 carisoprodol, but it will not harm the person.
- Stay with the person and place them on their side if they are drowsy or vomiting.
What is carisoprodol withdrawal like, and how long does it last?
After high doses or prolonged use, stopping carisoprodol can cause withdrawal similar to meprobamate or barbiturate withdrawal.
- Days 1 to 2Symptoms beginInsomnia, anxiety, tremor, vomiting, stomach cramps.
- Days 2 to 7PeakMuscle twitching, hallucinations, and, rarely, seizures.
- WeeksRecoveryGradual return to normal.
See the withdrawal timelines and the full carisoprodol withdrawal guide.
Is carisoprodol legal?
In the United States, carisoprodol 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 |
|---|---|
| European Union | Marketing authorizations suspended in 2008 because of misuse |
| Canada | Prescription medicine; not widely marketed |
| International | Not under UN control; controlled nationally |
Frequently asked questions about carisoprodol
Is Soma a narcotic?
No. It is a muscle relaxant, but it is a Schedule IV controlled substance because its metabolite meprobamate is sedating and habit-forming.
How long can you take carisoprodol?
Only two to three weeks. Muscle problems lasting longer need other treatment.
Why is carisoprodol dangerous with opioids?
Both depress the central nervous system. With an opioid and a benzodiazepine, the combination has caused many fatal overdoses.
Is carisoprodol banned anywhere?
Yes. The European Union suspended its marketing in 2008 because of misuse and safety concerns.
Sources
- Soma (carisoprodol) 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 Carisoprodol profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
