Short answer: Diazepam (Valium) is a long-acting benzodiazepine used for anxiety, alcohol withdrawal, muscle spasms, and seizures. Its long half-life makes it a common choice for tapering people off shorter-acting benzodiazepines. It is a Schedule IV controlled substance.
Key takeaways
- What it is: Diazepam is a long-acting benzodiazepine and a Schedule IV controlled substance in the US.
- Main uses: Anxiety; alcohol withdrawal; spasm; seizures.
- Timing: effects start in 15 to 60 minutes and last effects can last a day or more.
- Most dangerous mix: Opioids (oxycodone, fentanyl, codeine), which can cause slowed breathing, coma, death.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: High.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is diazepam?
Diazepam is approved for anxiety disorders, short-term relief of anxiety symptoms, acute alcohol withdrawal, as an add-on for skeletal muscle spasm, and as an add-on for convulsive disorders. The nasal spray and rectal gel treat seizure clusters outside the hospital.
Diazepam and its active metabolite, desmethyldiazepam, stay in the body for days. This smooths out blood levels, which is why clinicians often switch patients to diazepam before a slow benzodiazepine taper.
Quick facts
| Fact | Diazepam |
|---|---|
| Generic name | Diazepam |
| Brand names | Valium; Valtoco (nasal); Diastat (rectal gel) |
| Drug class | Long-acting benzodiazepine |
| US legal status | Schedule IV, prescription only |
| Approved uses | Anxiety, acute alcohol withdrawal, muscle spasm, seizure clusters (adjunct) |
| Forms | Tablets, oral solution, nasal spray, rectal gel, injection |
| Onset | 15 to 60 minutes by mouth |
| Half-life | Up to 48 hours; active metabolite up to 100 hours |
| Broken down by | CYP3A4 and CYP2C19 |
How long does diazepam last?
- Starts working: 15 to 60 minutes
- Effects last: Effects can last a day or more
- Half-life: Up to 48 hours; active metabolite up to 100 hours
Diazepam and its active metabolite can remain for several days to more than a week. Urine tests can detect it for up to 10 days, and longer after heavy use.
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 diazepam?
The FDA requires boxed warnings, its strongest, on diazepam products, including:
- Taking benzodiazepines with opioids can cause profound sedation, slowed breathing, coma, and death.
- Benzodiazepines can be misused and can lead to addiction, which raises the risk of overdose and death.
- Regular use can cause physical dependence. Stopping suddenly or cutting the dose quickly can cause withdrawal reactions, including seizures, that can be life-threatening.
Common side effects include drowsiness, fatigue, muscle weakness, and poor coordination.
Accumulation: because diazepam builds up over days, sedation can increase over the first week, especially in older adults and people with liver disease. It is on the Beers list of medicines older adults should usually avoid.
What should you never mix with diazepam?
| Combined with | What happens | Label guidance |
|---|---|---|
| Opioids (oxycodone, fentanyl, codeine) | Slowed breathing, coma, death | Boxed warning; avoid unless no alternative |
| Alcohol | Stronger sedation and slowed breathing | Avoid |
| Other sedatives, sleep medicines, gabapentinoids | Additive drowsiness and impaired coordination | Use caution |
| Fluconazole, fluvoxamine, omeprazole, ketoconazole | Raise diazepam levels | Use caution |
| Rifampin, carbamazepine | Lower diazepam levels | May reduce effect |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a diazepam overdose, and what should you do?
Diazepam overdose causes deep sleepiness, confusion, slurred speech, poor coordination, and, with opioids or alcohol, slowed or stopped breathing.
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 diazepam, 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 diazepam withdrawal like, and how long does it last?
People who take diazepam regularly, even as prescribed, can become physically dependent within weeks. Because diazepam lasts so long, withdrawal starts later, often several days after the last dose, and tends to be gentler at onset.
- Days 2 to 7Symptoms beginRebound anxiety, insomnia, restlessness, sweating, and tremor.
- Weeks 1 to 4Acute withdrawalPanic, irritability, muscle pain, nausea, sensitivity to light and sound, and in severe cases seizures or delirium.
- MonthsProtracted symptoms in some peopleA minority have lingering anxiety, poor sleep, low mood, or tingling that can last weeks to more than 12 months.
See the withdrawal timelines and the full diazepam withdrawal guide.
Is diazepam legal?
In the United States, diazepam 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 |
|---|---|
| United Kingdom | Class C; prescription only |
| Canada | Schedule IV (targeted substance); prescription only |
| Australia | Schedule 4 prescription medicine |
| International | Schedule IV of the 1971 Convention on Psychotropic Substances |
Frequently asked questions about diazepam
How long does diazepam stay in your system?
Diazepam and its active metabolite can remain for several days to more than a week. Urine tests can detect it for up to 10 days, and longer after heavy use.
Is Valium stronger than Xanax?
Per milligram, alprazolam is about 10 to 20 times as potent, but diazepam lasts much longer. 10 mg of diazepam is roughly equivalent to 0.5 to 1 mg of alprazolam.
Why is diazepam used for alcohol withdrawal?
It calms the overactive brain state of withdrawal, prevents seizures, and lasts long enough to provide a smooth, self-tapering effect.
Can diazepam be used for muscle spasms?
Yes, as an add-on for spasm from injury or conditions such as cerebral palsy.
Sources
- Valium (diazepam) prescribing information, DailyMed, US National Library of Medicine.
- FDA warns about serious risks and death when combining opioid pain or cough medicines with benzodiazepines, US Food and Drug Administration, 2016.
- FDA requiring Boxed Warning updated to improve safe use of benzodiazepine drug class, US Food and Drug Administration, 2020.
- Joint Clinical Practice Guideline on Benzodiazepine Tapering, American Society of Addiction Medicine, 2025.
- 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.
This guide summarizes the sourced DoseUses Diazepam profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
