Short answer: The diethylpropion label lists side effects without percentages: chest pain, irregular or fast heartbeat, raised blood pressure, nervousness, restlessness, insomnia, dizziness, headache, dry mouth, nausea, constipation, rash, and libido changes, among others. Its warnings cover pulmonary hypertension, heart valve disease, tolerance, dependence and psychosis. The label has no boxed warning and gives the schedule as schedule IV.
What Diethylpropion is approved for: Diethylpropion is approved as a short-term (a few weeks) add-on to a calorie-restricted weight-loss plan for obesity in people with a starting BMI of 30 kg/m2 or more who have not responded to diet and/or exercise alone (Indications and Usage). The label says diethylpropion tablets are schedule IV controlled substances (Drug Abuse and Dependence).
Source
Diethylpropion Hydrochloride Tablets USP, 25 mg, CIV, prescribing information. PD-Rx Pharmaceuticals (repackager). DailyMed, version published October 19, 2026. DailyMed setid 5777eed8-c63d-49c4-9dd1-9d087906c368
No. The current Diethylpropion label has no boxed warning.
These are the label's own numbers from the Adverse Reactions section. Where the label compares with placebo (a dummy treatment), both columns are shown, so you can see how much more often a reaction happened on Diethylpropion.
| Body system | Reactions listed |
|---|---|
| Cardiovascular | Precordial pain, arrhythmia (including ventricular), ECG changes, tachycardia, elevation of blood pressure, palpitation and rare reports of pulmonary hypertension. Valvulopathy has been very rarely reported with diethylpropion monotherapy, but the causal relationship remains uncertain. |
| Central nervous system | In a few epileptics an increase in convulsive episodes; rarely psychotic episodes at recommended doses; dyskinesia, blurred vision, overstimulation, nervousness, restlessness, dizziness, jitteriness, insomnia, anxiety, euphoria, depression, dysphoria, tremor, mydriasis, drowsiness, malaise, headache, and cerebrovascular accident |
| Gastrointestinal | Vomiting, diarrhea, abdominal discomfort, dryness of the mouth, unpleasant taste, nausea, constipation, other gastrointestinal disturbances |
| Allergic | Urticaria, rash, ecchymosis, erythema |
| Endocrine | Impotence, changes in libido, gynecomastia, menstrual upset |
| Hematopoietic system | Bone marrow depression, agranulocytosis, leukopenia |
| Miscellaneous | Dysuria, dyspnea, hair loss, muscle pain, increased sweating, and polyuria |
In a case-control study, use of appetite-suppressant ("anorectic") drugs for longer than 3 months was linked to a 23-fold increase in the risk of pulmonary hypertension.
In short trials, extra weight loss over placebo averaged some fraction of a pound a week, and was greatest in the first weeks. Tolerance has been seen with all drugs of this class.
Between 75 and 106% of a dose is recovered in the urine within 48 hours. The half-life of the aminoketone metabolites is estimated at 4 to 6 hours.
Stopping suddenly after long use of high doses leads to extreme fatigue and depression. Signs of chronic misuse include severe skin problems, marked insomnia, irritability, hyperactivity and personality changes; the most severe is psychosis.
Signs of overdose include restlessness, tremor, overactive reflexes, fast breathing, confusion, hallucinations and panic, followed by fatigue and depression, plus heart rhythm and blood pressure changes.
The Warnings and Precautions part of the label lists these. Each line gives the label's heading and what it means in plain words.
Who should not use it. People with pulmonary hypertension, advanced hardening of the arteries, an overactive thyroid, allergy to stimulant amines, glaucoma or severe high blood pressure; people in agitated states or with a history of drug abuse; anyone using another appetite suppressant; and anyone within 14 days of an MAO inhibitor.
Pulmonary hypertension. This rare, often fatal lung disease has been linked to appetite suppressants including diethylpropion. New or worse shortness of breath on exertion, chest pain, fainting or leg swelling suggest it, and the drug is stopped right away.
Heart valve disease. Heart valve disease has been reported with some appetite suppressants, and very rarely with diethylpropion alone, with the link uncertain. It is not recommended with a known heart murmur or valve disease, and a heart check before starting may be considered.
Continue only with early weight loss. Treatment is continued only with satisfactory weight loss in the first 4 weeks, for example at least 4 pounds. It is not recommended for people who used any appetite suppressant in the prior year.
Tolerance and dependence. If tolerance develops, the dose is not raised; the drug is stopped instead. Long use may cause dependence with withdrawal on stopping. Rare hallucinations and toxic psychosis have been reported.
Driving and alcohol. Diethylpropion may impair driving or operating machinery, and possible interactions with alcohol are considered.
Heart disease, high blood pressure and epilepsy. Caution is used with high blood pressure or heart disease including arrhythmias, and it is not given with severe high blood pressure. It may increase seizures in some people with epilepsy, who are watched carefully.
From the Warnings that comes with Diethylpropion:
Dose Track has a side-effect log. Each entry records the symptom, a severity (none, mild, moderate, severe or life-threatening), the date and an optional note, and can be tied to a specific dose or logged on its own. The history screen shows what you logged over time, which makes it easier to tell your prescriber when a reaction started and whether it is easing. The app records what you enter; it does not judge whether a symptom is serious. For anything on the label's call-your-doctor list, call your doctor.
This page is what the FDA label says, in plain words. It is not medical advice. Follow your prescriber, and ask them or your pharmacist about anything here.