Contrave vs. Phentermine
See how Contrave and Phentermine compare on approved uses, dosing, side effects, and cost.
Key Takeaways
Contrave is FDA-approved for long-term chronic weight management, while phentermine is approved only for short-term use of a few weeks.
Contrave combines an opioid antagonist and an antidepressant to curb appetite and cravings, while phentermine is a stimulant-like amine that suppresses hunger directly.
Phentermine is a Schedule IV controlled substance with abuse and dependence risk, while Contrave carries a boxed warning for suicidal thoughts tied to its bupropion component.
Contrave vs. Phentermine Drug Summary
Contrave
Contrave combines naltrexone, an opioid antagonist, with bupropion, an antidepressant, to help reduce appetite and food cravings. It is FDA-approved for chronic weight management in adults with obesity, or who are overweight with a weight-related condition. The extended-release tablet is taken twice daily after a short dose-up schedule.
Phentermine
Phentermine is a stimulant-like appetite suppressant approved only for short-term weight loss, usually just a few weeks. It works by prompting the body to release norepinephrine, which reduces hunger signals. The tablet or capsule is taken once daily, typically in the morning.
Contrave vs. Phentermine Side Effects
Contrave
Phentermine
Contrave vs. Phentermine Dosage
Contrave
Phentermine
| STAGE | DOSE | WHEN |
| Starting dose | 8 mg/90 mg once daily | Week 1 |
| Maximum dose | 16 mg/180 mg twice daily | Week 3 |
| Dose changes | 2 increases | Every week |
| STAGE | DOSE | WHEN |
| Starting dose | 37.5 mg once daily | At the start |
| Maximum dose | 15 mg once daily | If needed |
| Dose changes | 1 increase | As tolerated |
Contrave
| STAGE | DOSE | WHEN |
| Starting dose | 8 mg/90 mg once daily | Week 1 |
| Maximum dose | 16 mg/180 mg twice daily | Week 3 |
| Dose changes | 2 increases | Every week |
Phentermine
| STAGE | DOSE | WHEN |
| Starting dose | 37.5 mg once daily | At the start |
| Maximum dose | 15 mg once daily | If needed |
| Dose changes | 1 increase | As tolerated |
Contrave vs. Phentermine Indications
Contrave
Contrave is FDA-approved for chronic weight management in adults with obesity, or who are overweight with at least one weight-related condition such as high blood pressure or type 2 diabetes. It is meant for long-term use alongside a reduced-calorie diet and increased physical activity. It is not approved for depression, smoking cessation, or use in children.
Chronic, long-term weight management
Adults with obesity (BMI ≥30) or overweight with a comorbidity
Used with reduced-calorie diet and exercise
Not approved for depression or smoking cessation
Phentermine
Phentermine is FDA-approved only as a short-term aid, typically just a few weeks, for weight reduction in adults with obesity. It is meant to be combined with exercise, behavior changes, and calorie restriction. It is not approved for long-term use or for patients 16 and younger.
Short-term use, typically a few weeks
Adults with BMI ≥30, or ≥27 with risk factors
Used with diet, exercise, and behavior change
Not approved for long-term weight management
Contrave vs. Phentermine Pros and Cons
Contrave
Contrave's combination of naltrexone and bupropion targets both appetite and food cravings, and it is approved for ongoing use rather than a few weeks. It is not a controlled substance, but it carries a boxed warning and several contraindications tied to its bupropion component.
Pros
Approved for long-term, ongoing weight management
Not a controlled substance, no abuse or dependence risk
May help reduce food cravings, not just appetite
Non-stimulant, less likely to cause jitteriness or rapid heartbeat
Cons
Boxed warning for suicidal thoughts and behaviors
Slower to reach full effective dose due to titration
Roughly $750 to $840 per month without insurance, pricier than phentermine
Contraindicated with seizure history, uncontrolled hypertension, or opioid use
Phentermine
Phentermine works quickly and costs far less than most prescription weight-loss options, but it is only meant for short-term use. As a controlled stimulant, it carries risks of dependence and cardiovascular side effects that Contrave does not share.
Pros
Roughly $15 to $75 per month without insurance, one of the least expensive weight-loss drugs
Fast-acting appetite suppression, no titration needed
Long track record of use since 1959
Simple once-daily dosing
Cons
Only approved for short-term use, a few weeks
Schedule IV controlled substance with abuse and dependence risk
Can raise heart rate and blood pressure
Withdrawal effects possible after prolonged high-dose use
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