Active ingredient
Phentermine-topiramate (extended release): FDA Status, Uses, Safety and Cost
Combination of two medications
What Phentermine-topiramate (extended release) is
Qsymia combines two older medications — phentermine (an appetite suppressant) and topiramate (an antiepileptic that affects appetite) — in a once-daily extended-release capsule approved for chronic weight management. It was one of two weight-management drugs approved in 2012, ending a 13-year gap in new obesity-drug approvals.
Key facts
| Generic (active ingredient) | Phentermine-topiramate (extended release) |
|---|---|
| Brand names | Qsymia |
| Drug class | Sympathomimetic amine + antiepileptic (combination) |
| Manufacturer | Vivus |
| FDA status | FDA ApprovedApproved for chronic weight management |
| Administration | Oral capsule (extended release) |
| Frequency | Once daily |
| Approval date | July 2012 |
| Prescription required | Yes |
| Controlled substance | Schedule IV |
| Official label | Prescribing information (DailyMed) |
What Phentermine-topiramate (extended release) is approved for
- Chronic weight management in adults with obesity, or overweight with at least one weight-related condition, as an adjunct to a reduced-calorie diet and increased physical activity
- Chronic weight management in certain pediatric patients aged 12 and older (per current labeling)
How Phentermine-topiramate (extended release) works
The combination pairs phentermine’s stimulant-mediated appetite suppression with topiramate’s appetite and satiety effects; the precise mechanism of topiramate’s effect on weight is not fully established in labeling.
Administration
Phentermine-topiramate (extended release) is given by oral capsule (extended release), once daily.
We do not publish dosing guidance
Dose selection, titration schedules, and what to do about a missed dose are individual clinical decisions. Follow the instructions from your prescriber and the official prescribing information — never a website.
Important safety information
The FDA labeling for Phentermine-topiramate (extended release) does not include a boxed warning. It does include warnings and precautions — read the full prescribing information, linked in Sources below.
Contraindications (who should not take it)
- Pregnancy (topiramate can cause fetal harm, including oral clefts — a Risk Evaluation and Mitigation Strategy applies)
- Glaucoma
- Hyperthyroidism
- Use during or within 14 days of MAO inhibitors
- Known hypersensitivity to components
Summarized from the FDA prescribing information. This is not the complete list — see the full label.
Common adverse reactions from official labeling
- Paraesthesia (tingling)
- Dizziness
- Altered taste (dysgeusia)
- Insomnia
- Constipation
- Dry mouth
The most common adverse reactions listed in the product’s FDA prescribing information. Frequency and full adverse-reaction data are in the label.
Cost and access
- Prescription only; dispensed under a REMS program because of fetal-harm risk — pregnancy testing requirements apply for patients who can become pregnant.
- The manufacturer operates savings programs and a home-delivery option; check current terms on the manufacturer site.
Why we don't publish a price
List prices, savings-card amounts, and self-pay offers change frequently and vary by pharmacy, plan, and location. Any figure we printed would be wrong for many readers and stale within weeks. See our cost guide for how to get an accurate number for your own situation.
Insurance considerations
- Coverage varies; some plans cover Qsymia where GLP-1 weight-loss drugs are excluded, and vice versa.
More detail: how insurance coverage works for weight-loss medication.
Frequently asked questions
- Is Qsymia a GLP-1 medication?
- No. Qsymia combines phentermine and topiramate — neither is a GLP-1 receptor agonist. It is an oral option approved for chronic weight management.
- Why does Qsymia have pregnancy restrictions?
- Topiramate exposure in pregnancy is associated with increased risk of oral clefts in infants. Qsymia is contraindicated in pregnancy and dispensed under an FDA-required risk-management program.
Sources
- Qsymia prescribing information (DailyMed, NIH) — DailyMed/NIH. Link last verified August 12, 2026.
- Drugs@FDA database — FDA. Link last verified August 12, 2026.
- Qsymia manufacturer site — Manufacturer. Link last verified August 12, 2026.
Not medical advice. WeightLossDrugsGuide is an independent educational publisher. We are not a pharmacy, a medical provider, or a telehealth clinic, and we do not provide personalized medical recommendations or dosing guidance. Information here summarizes official FDA labeling and other primary sources and may not reflect the most recent changes. Always talk with a licensed clinician about your own situation, and read the full prescribing information for any medication.