Contrave is not a GLP-1 drug. It belongs to a completely different class of weight loss medication. While GLP-1 drugs like Wegovy and Ozempic mimic a gut hormone that regulates appetite and blood sugar, Contrave combines two older medications, naltrexone and bupropion, that work on the brain’s appetite and reward centers. The two approaches to weight loss share almost nothing in common beyond the goal itself.
How Contrave Actually Works
Contrave pairs two well-established drugs into a single tablet. Bupropion, originally developed as an antidepressant and smoking cessation aid, acts on brain chemicals involved in appetite regulation. It stimulates neurons in the hypothalamus, the brain region that controls hunger signals, helping reduce the drive to eat. Naltrexone, originally used to treat alcohol and opioid dependence, blocks opioid receptors in the brain’s reward system. This dampens the pleasurable response to food, making it easier to resist cravings and overeating.
Together, the two compounds reinforce each other. Bupropion activates appetite-suppressing pathways, while naltrexone prevents the brain from shutting those pathways down (which it would normally do through its own internal opioid signaling). The result is a sustained reduction in hunger and food cravings that neither drug achieves as effectively on its own.
How GLP-1 Drugs Work Differently
GLP-1 receptor agonists like semaglutide (Wegovy, Ozempic) and tirzepatide (Zepbound, Mounjaro) mimic a hormone called glucagon-like peptide-1 that your gut naturally releases after eating. This hormone slows stomach emptying, so food stays in your digestive system longer and you feel full sooner. It also signals the brain to reduce appetite and helps regulate blood sugar by prompting the pancreas to release insulin when needed.
The differences extend beyond mechanism. GLP-1 drugs are injections, typically given once a week. Contrave is an oral pill taken twice daily. GLP-1 drugs tend to produce significantly greater weight loss. And the side effect profiles are distinct: GLP-1 drugs are known for gastrointestinal issues like nausea and diarrhea, while Contrave’s risks lean more toward neuropsychiatric effects.
Weight Loss: What the Numbers Show
In the COR-I clinical trial, people taking Contrave at its standard dose lost an average of 6.1% of their body weight over 56 weeks, compared to 1.3% in the placebo group. That translates to roughly 13 to 15 pounds for someone starting at 230 pounds.
GLP-1 drugs generally produce larger results. Semaglutide at the weight management dose has shown average weight loss of around 15% of body weight in major trials, roughly two and a half times what Contrave delivers. Tirzepatide has demonstrated even higher numbers in some studies. Both the American Gastroenterological Association and other major medical groups include Contrave and GLP-1 drugs in their obesity treatment recommendations, but the expected outcomes are meaningfully different.
Taking Contrave: What to Expect
Contrave is taken as a pill, which is one reason some people prefer it over injectable GLP-1 medications. The dose builds gradually over four weeks. You start with one tablet in the morning during week one, add an evening tablet in week two, increase to two morning tablets plus one evening tablet in week three, and reach the full maintenance dose of two tablets twice daily by week four. Each tablet contains 8 mg of naltrexone and 90 mg of bupropion, so the full daily dose is 32 mg/360 mg.
This slow ramp-up helps your body adjust and reduces side effects. The most common ones are nausea, constipation, headache, and insomnia. Nausea tends to be worst in the early weeks and often improves as your body acclimates.
Who Should Not Take Contrave
Because Contrave contains naltrexone, an opioid blocker, it cannot be used by anyone currently taking opioid medications or in opioid withdrawal. This includes prescription painkillers and opioid substitution therapy. Taking Contrave while on opioids can trigger sudden and severe withdrawal symptoms.
Bupropion lowers the seizure threshold, so Contrave is off limits for anyone with a seizure disorder or a history of seizures. It’s also contraindicated for people with a history of bipolar disorder, current or past eating disorders (bulimia or anorexia nervosa), uncontrolled high blood pressure, or those undergoing alcohol or benzodiazepine withdrawal. People taking MAO inhibitors, a class of antidepressant, also cannot use Contrave.
GLP-1 drugs have a different set of restrictions, largely centered around a family history of certain thyroid cancers and a personal history of pancreatitis. The two drug classes are suited to different patient profiles, which is partly why both remain on the market.
Why the Confusion Exists
Contrave and GLP-1 drugs get lumped together because they’re both FDA-approved for chronic weight management in adults with a BMI of 30 or higher, or 27 or higher with at least one weight-related condition like high blood pressure or type 2 diabetes. Contrave received FDA approval in September 2014, well before the GLP-1 weight loss boom that began when semaglutide was approved for obesity in 2021.
The surge of interest in GLP-1 drugs has led many people to assume all prescription weight loss medications work the same way. They don’t. Contrave acts entirely within the brain, targeting appetite regulation and food reward pathways. GLP-1 drugs act on the gut, pancreas, and brain simultaneously through hormonal signaling. The cost, delivery method, side effects, and degree of weight loss all differ substantially between the two categories.