Contrave vs Qsymia: Weight-Loss Pills Compared | Dose Track
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Contrave vs Qsymia: how do the two weight-loss pills compare?

Ingredients · Dosing · Trial results · Warnings

Short answer: Both are daily pills for long-term weight management alongside diet and exercise. Contrave combines naltrexone and bupropion, taken twice daily, and carries a boxed warning about suicidal thoughts.1 Qsymia combines phentermine and topiramate, taken once each morning; it is a Schedule IV controlled substance and needs monthly pregnancy tests in people who can become pregnant.2

How do Contrave and Qsymia compare side by side?

From the US Contrave and Qsymia labels.
ContraveQsymia
IngredientsNaltrexone (opioid antagonist) + bupropion (antidepressant), extended release1Phentermine (sympathomimetic) + topiramate, extended release2
Approved forAdults with obesity, or overweight with at least one weight-related condition1Adults with obesity, or overweight with a weight-related condition; also ages 12 and up with obesity2
Label dosing1 tablet (8 mg/90 mg) a day in week 1, stepping up to 2 tablets twice daily from week 4 (32 mg/360 mg a day)13.75 mg/23 mg each morning for 14 days, then 7.5 mg/46 mg; may go to 11.25/69 then 15/92 mg2
When to stopIf under 5% weight loss after 12 weeks on the full dose1If under 5% weight loss after 12 weeks on 15 mg/92 mg (adults); taper the top dose over at least a week2
Main 1-year trial (adults)COR-I, 56 weeks: −5.4% vs −1.3% on placebo1Study 1, 56 weeks: −10.9% on 15/92 mg and −5.1% on 3.75/23 mg vs −1.6% on placebo2
Reached at least 5% loss42% vs 17% on placebo (COR-I)167% on 15/92 mg vs 17% on placebo (Study 1)2
Boxed warningSuicidal thoughts and behaviors1None
Controlled substanceNoSchedule IV (phentermine)2
Most common side effectsNausea 32.5% vs 6.7% on placebo, constipation 19.2% vs 7.2%, headache 17.6% vs 10.4%1Tingling (paresthesia), dizziness, altered taste, insomnia, constipation, dry mouth2

Reviewed . Half-life figures are shown only where the value Dose Track uses agrees with the cited source.

What did the trials show?

Contrave and Qsymia have never been compared in the same trial. Each label reports its own 56-week, placebo-controlled studies:

  • Contrave: COR-I −5.4% vs −1.3%; COR-BMOD (with intensive behavior therapy) −8.1% vs −4.9%; COR-Diabetes −3.7% vs −1.7%.1 About 24% on Contrave and 12% on placebo stopped because of side effects.1
  • Qsymia: Study 1 (BMI 35 or more) −10.9% on 15/92 mg; Study 2 (overweight or obesity with 2 or more conditions) −7.8% on 7.5/46 mg and −9.8% on 15/92 mg vs −1.2% on placebo.2

These numbers come from separate placebo-controlled trials with different people, lengths and methods, so they are not a head-to-head comparison.

Who should not take each one?

  • Contrave is not for people with uncontrolled high blood pressure, seizures, an eating disorder, chronic opioid use, other bupropion products or an MAOI in the last 14 days.1
  • Qsymia is not for use in pregnancy: topiramate raises the risk of oral clefts. The label asks for a negative pregnancy test before starting and monthly during treatment.2

More detail: Contrave side effects, Qsymia side effects, and the Contrave and Qsymia dosing schedules.

How do they compare with GLP-1 drugs?

Neither has been tested head to head with a GLP-1 drug. For how Contrave's label numbers sit next to Wegovy's, see Wegovy vs Contrave: what do the labels show?.

Wegovy vs Contrave: what do the labels show?Weekly GLP-1 shot vs twice-daily pill Wegovy vs Zepbound: what is each one approved for?Heart risk, MASH, sleep apnea, tablets Semaglutide vs tirzepatide: what did the head-to-head trial show?SURMOUNT-5 results, label titration, half-life

Frequently asked questions

Which works better, Contrave or Qsymia?+
No trial has compared them. In their own 56-week trials, Contrave averaged −5.4% vs −1.3% on placebo (COR-I) and Qsymia 15/92 mg averaged −10.9% vs −1.6% (Study 1), in different groups of people.12
Is Qsymia a controlled substance?+
Yes. Its phentermine is Schedule IV. Topiramate is not controlled. Contrave is not a controlled substance.2
Does Contrave have a boxed warning?+
Yes, for suicidal thoughts and behaviors, because it contains the antidepressant bupropion. Qsymia has no boxed warning.1
How soon do you know if it is working?+
Both labels set a 12-week check. Contrave: stop if under 5% weight loss after 12 weeks on the full dose. Qsymia: step up at 12 weeks if under 3%, and stop if under 5% after 12 weeks on the top dose.12
Can I track Contrave or Qsymia in Dose Track?+
Yes. Both are built in. Log each dose, follow the step-up weeks with reminders, and keep your weight entries next to them.

Sources

  1. Contrave (naltrexone and bupropion) extended-release tablets prescribing information, including boxed warning and sections 1, 2, 4, 6 and 14. DailyMed, version of November 2025.
  2. Qsymia (phentermine and topiramate extended-release) capsules prescribing information, sections 1, 2, 5, 6, 9 and 14. DailyMed, version of April 2026.

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