Short answer: Methadone is a long-acting opioid used to treat opioid use disorder and severe pain. As treatment for addiction, it cuts the risk of death by about half, but it is dispensed for that purpose only through federally certified opioid treatment programs. It is a Schedule II controlled substance with a long, unpredictable half-life that makes early dosing risky.
Key takeaways
- What it is: Methadone is a long-acting opioid agonist and a Schedule II controlled substance in the US.
- Main uses: Opioid use disorder; severe pain.
- Timing: effects start in 30 to 60 minutes and last pain relief 4 to 8 hours; withdrawal prevention 24 to 36 hours.
- Most dangerous mix: Benzodiazepines (alprazolam, diazepam, clonazepam), which can cause profound sedation, slowed breathing, coma, death.
- Naloxone: it reverses an overdose (, often needs repeat doses).
- Dependence risk: High.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is methadone?
Methadone is approved for detoxification and maintenance treatment of opioid use disorder, and for severe pain when other treatments are inadequate.
As a treatment for opioid use disorder, methadone is taken once a day. It prevents withdrawal and reduces cravings without producing a high in tolerant patients, and it blocks the effects of other opioids. Treatment with methadone or buprenorphine reduces the risk of death by about 50%.
Quick facts
| Fact | Methadone |
|---|---|
| Generic name | Methadone hydrochloride |
| Brand names | Methadose, Dolophine |
| Drug class | Long-acting opioid agonist; NMDA antagonist |
| US legal status | Schedule II; opioid use disorder treatment only in certified programs |
| Approved uses | Opioid use disorder; severe pain |
| Forms | Tablets, dispersible tablets, oral concentrate, injection |
| Onset | 30 to 60 minutes |
| Half-life | 8 to 59 hours; often about 24 hours |
| Broken down by | CYP3A4, CYP2B6, CYP2C19 |
How long does methadone last?
- Starts working: 30 to 60 minutes
- Effects last: Pain relief 4 to 8 hours; withdrawal prevention 24 to 36 hours
- Half-life: 8 to 59 hours; often about 24 hours
Its half-life ranges from 8 to 59 hours. Urine tests can detect it for up to 1 to 2 weeks.
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 methadone?
The FDA requires boxed warnings, its strongest, on methadone products, including:
- Methadone exposes users to risks of addiction, misuse, and abuse, which can lead to overdose and death.
- Life-threatening slowed breathing can occur, especially when starting treatment or after a dose increase.
- Accidental ingestion, especially by children, can cause a fatal overdose.
- Use with benzodiazepines or other central nervous system depressants, including alcohol, can cause profound sedation, slowed breathing, coma, and death.
Common side effects include constipation, sweating, drowsiness, weight gain, lowered sex drive, and dizziness.
Delayed overdose: methadone's peak breathing effect comes later and lasts longer than its pain relief. Taking extra doses for pain can cause overdose hours later, often during sleep.
What should you never mix with methadone?
| Combined with | What happens | Label guidance |
|---|---|---|
| Benzodiazepines (alprazolam, diazepam, clonazepam) | Profound sedation, slowed breathing, coma, death | Boxed warning; avoid unless no alternative |
| Alcohol | Stronger sedation and slowed breathing | Avoid |
| Gabapentin, pregabalin, sleep medicines, muscle relaxants | Additive sedation and breathing problems | Use caution; lower doses |
| Drugs that prolong QT (some antibiotics, antipsychotics, antiarrhythmics) | Dangerous heart rhythm | Avoid or monitor ECG |
| Rifampin, carbamazepine, phenytoin, efavirenz | Lower methadone levels; withdrawal | Dose adjustment needed |
| Fluconazole, ciprofloxacin, some HIV drugs | Raise methadone levels | Monitor closely |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a methadone overdose, and what should you do?
Methadone overdose causes deep sleepiness, slow or stopped breathing, and pinpoint pupils. Because methadone lasts so long, a person revived with naloxone can slip back into overdose hours later and needs hospital monitoring.
If someone may have overdosed
- Call 911 if the person is unresponsive, cannot be woken, has blue or gray lips, or is breathing slowly or not at all.
- Give naloxone (Narcan or a generic nasal spray, sold without a prescription) into one nostril. If there is no response after 2 to 3 minutes, give another dose.
- If you are trained, give rescue breaths. Otherwise place the person on their side so they do not choke.
- Stay with them. Naloxone can wear off before methadone does, so the overdose can return even after the person wakes up.
- Most states have Good Samaritan laws that protect people who call 911 for an overdose from some drug charges.
What is methadone withdrawal like, and how long does it last?
People who take methadone regularly for more than a few weeks become physically dependent, even when they take it exactly as prescribed. Dependence is not the same as addiction, but it means stopping suddenly causes withdrawal.
- 24 to 48 hoursEarly symptomsAnxiety, restlessness, yawning, sweating, runny nose, watery eyes, and muscle aches.
- Days 3 to 8Peak withdrawalDiarrhea, stomach cramps, nausea and vomiting, goosebumps, dilated pupils, fast heartbeat, and strong cravings. Rarely dangerous in healthy adults, but dehydration can be serious.
- Weeks to monthsLingering symptomsPoor sleep, low mood, low energy, and cravings can continue for weeks. Tolerance falls quickly, which raises the risk of overdose if use restarts.
See the withdrawal timelines and the full methadone withdrawal guide.
Is methadone legal?
In the United States, methadone is a Schedule II 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: Schedule II prescriptions cannot be refilled. A prescriber can write several prescriptions at once, with dates when each may be filled, for up to a 90-day supply in total.
- 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 A; prescription only |
| Canada | Schedule I of the Controlled Drugs and Substances Act; prescription only |
| Australia | Schedule 8 controlled drug; prescription only |
| International | Schedule I of the 1961 Single Convention on Narcotic Drugs |
Frequently asked questions about methadone
Does methadone treatment work?
Yes. Decades of research show methadone treatment reduces illicit opioid use, HIV and hepatitis C transmission, crime, and overdose deaths, cutting death risk by about half.
Why do I have to go to a clinic for methadone?
Federal law limits methadone for opioid use disorder to certified opioid treatment programs. Stable patients can receive take-home doses for up to 28 days under the 2024 rules.
Is methadone just replacing one drug with another?
No. At a stable dose, methadone does not cause a high in tolerant patients, allows normal functioning, and treats a medical condition, like insulin for diabetes.
How long does methadone stay in your system?
Its half-life ranges from 8 to 59 hours. Urine tests can detect it for up to 1 to 2 weeks.
Is methadone dangerous for the heart?
At higher doses it can prolong the QT interval and cause dangerous heart rhythms. Programs check ECGs in people at risk.
Sources
- Methadose (methadone) prescribing information, DailyMed, US National Library of Medicine.
- FindTreatment.gov, Substance Abuse and Mental Health Services Administration.
- Information about naloxone and nalmefene, US Food and Drug Administration.
- CDC Clinical Practice Guideline for Prescribing Opioids for Pain, 2022, Centers for Disease Control and Prevention, MMWR.
- Controlled Substance Schedules, DEA Diversion Control Division.
- 21 CFR 1306.12, Refilling prescriptions; issuance of multiple prescriptions (Schedule II), 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 Methadone profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
