Short answer: Diethylpropion, called amfepramone outside the US, is a prescription appetite suppressant for a few weeks of use in obesity. It is a Schedule IV controlled substance related to amphetamine. The European Union withdrew it in 2022 over misuse and heart and lung risks.
Key takeaways
- What it is: Diethylpropion is a sympathomimetic appetite suppressant and a Schedule IV controlled substance in the US.
- Main uses: Short-term treatment of obesity.
- Timing: effects start in about 1 hour and last 4 to 6 hours (IR); 10 to 14 hours (ER).
- Most dangerous mix: MAO inhibitors (within 14 days), which can cause hypertensive crisis.
- Naloxone: it does not reverse this drug, but give it whenever opioids could be involved.
- Dependence risk: Low to moderate.
- Legal route: only with a prescription from a DEA-registered clinician, filled by a licensed pharmacy.
What is diethylpropion?
Diethylpropion reduces appetite and is approved for a few weeks of use in a weight-loss program for people with a body mass index of 30 or more.
In 2022 the European Medicines Agency recommended revoking authorizations for amfepramone after finding it was used beyond recommended durations and in people with heart risk factors.
Quick facts
| Fact | Diethylpropion |
|---|---|
| Generic name | Diethylpropion hydrochloride |
| Other name | Amfepramone |
| Brand names | Tenuate, Tenuate Dospan (discontinued brands) |
| Drug class | Sympathomimetic amine (anorectic) |
| US legal status | Schedule IV, prescription only |
| Approved uses | Short-term (a few weeks) management of exogenous obesity |
| Forms | 25 mg tablets; 75 mg extended-release tablets |
| Onset | About 1 hour |
How long does diethylpropion last?
- Starts working: About 1 hour
- Effects last: 4 to 6 hours (IR); 10 to 14 hours (ER)
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 diethylpropion?
Common side effects include dry mouth, restlessness, insomnia, constipation, and fast heartbeat.
Heart and lungs: appetite-suppressant stimulants raise heart rate and blood pressure. Rare but serious risks include pulmonary arterial hypertension and heart valve disease, especially when combined with other weight-loss drugs.
Dependence: they are chemically related to amphetamine and can be misused; tolerance to the appetite effect develops within weeks.
What should you never mix with diethylpropion?
| Combined with | What happens | Label guidance |
|---|---|---|
| MAO inhibitors (within 14 days) | Hypertensive crisis | Contraindicated |
| Other weight-loss drugs and stimulants | Heart and lung risks; overstimulation | Do not combine |
| Alcohol | Dizziness and masked impairment | Avoid |
| Insulin and diabetes medicines | Lower blood sugar as appetite falls | Dose adjustment may be needed |
| Blood pressure medicines | Reduced effect | Monitor |
Check any combination with the DoseUses combination checker or ask a pharmacist.
What are the signs of a diethylpropion overdose, and what should you do?
Overdose causes restlessness, tremor, confusion, panic, hallucinations, high blood pressure, and abnormal heart rhythms.
If someone may be overdosing
- Call 911 for chest pain, a seizure, trouble breathing, signs of a stroke (face drooping, weakness on one side, slurred speech), a very high body temperature, or if the person collapses.
- Move them somewhere cool and calm, loosen tight clothing, and cool the skin with water. Do not try to hold them down.
- If they become unresponsive or their breathing slows, give naloxone. Street stimulants are often contaminated with fentanyl.
- For advice when the person is awake and stable, call Poison Help at 1-800-222-1222.
What is diethylpropion withdrawal like, and how long does it last?
Stopping diethylpropion after regular use does not cause dangerous physical withdrawal, but it can cause a temporary crash.
- Days 1 to 3CrashTiredness, increased sleep, hunger, and low mood.
- Week 1AdjustingLow energy, poor concentration, and irritability.
- Weeks 2 to 4SettlesMood and energy usually return to baseline.
See the withdrawal timelines and the full diethylpropion withdrawal guide.
Is diethylpropion legal?
In the United States, diethylpropion 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 revoked in 2022 |
| International | Schedule IV of the 1971 Convention on Psychotropic Substances (as amfepramone) |
Frequently asked questions about diethylpropion
Is diethylpropion still available in the US?
Yes, as a generic Schedule IV prescription medicine.
Why was amfepramone withdrawn in Europe?
Regulators found it was used too long and in people with heart risks, despite restrictions, and that risks outweighed benefits.
Is diethylpropion safer than phentermine?
Both have similar risks. Neither is meant for long-term use.
Can diethylpropion be used in pregnancy?
No. Weight loss is not recommended during pregnancy.
Is diethylpropion an amphetamine?
It is chemically related to amphetamine and cathinone but is milder.
Sources
- Tenuate (diethylpropion) prescription information, DailyMed, US National Library of Medicine.
- Amfepramone medicines to be removed from the EU market, European Medicines Agency, 2022.
- 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.
This guide summarizes the sourced DoseUses Diethylpropion profile, written from FDA labels, DEA rules, and federal health agencies. It is educational and is not medical advice. Last updated October 5, 2026.
