Does Wellbutrin Cause Weight Loss?

Quick Summary: Wellbutrin (bupropion) is an antidepressant approved for depression and seasonal affective disorder—not weight loss. Compared to other antidepressants, bupropion tends to cause the least weight gain, and some people lose a small amount. If weight management is your primary goal, a different medication called Contrave (naltrexone + bupropion) is actually FDA-approved for that purpose when combined with lifestyle changes.

What the Research Actually Shows

A major 2024 study published in Annals of Internal Medicine looked at over 183,000 adults starting one of eight common antidepressants for the first time. The researchers tracked weight changes at 6, 12, and 24 months.¹

The findings were clear: bupropion users gained the least weight compared to users of other first-line antidepressants. At six months, people taking bupropion were 15-20% less likely to gain a clinically significant amount of weight (5% or more of their baseline) than those taking sertraline, the most commonly prescribed antidepressant.¹ Some bupropion users actually lost a small amount—about half a pound on average at six months—though this reversed to a modest 1.2-pound gain by 24 months.²

Here's the important context: these are averages. Some people lose weight on bupropion, some stay the same, and some gain. The medication isn't a weight loss tool—it's simply less likely to cause the weight gain that often accompanies other antidepressants.

For a deeper look at medications specifically designed for weight management, see our complete guide to weight loss supplements.

Is Wellbutrin Prescribed for Weight Loss?

No, and this distinction matters. Bupropion is FDA-approved for major depressive disorder, seasonal affective disorder, and (under a different brand name, Zyban) smoking cessation. Prescribing it specifically for weight loss would be considered off-label use.

That said, clinicians sometimes consider bupropion's more favorable weight profile when choosing an antidepressant for someone who is concerned about gaining weight. It's not that the medication will help you lose weight—it's that it's less likely to work against your efforts than some alternatives.

Safety Basics You Need to Know

Before discussing any medication, certain safety information is non-negotiable:

Do not use bupropion if you have: A seizure disorder, or a current or prior diagnosis of bulimia or anorexia nervosa. Bupropion lowers the seizure threshold, and eating disorders that involve purging further increase this risk.³

Be aware: All antidepressants carry a boxed warning about suicidal thoughts and behavior in young people. Work closely with your prescriber, especially during the first few months of treatment or when doses change.

Never start, stop, or adjust your dose without your prescriber's guidance. This is educational information—not medical advice.

What Results Can You Realistically Expect?

There's no guaranteed effect when it comes to weight and bupropion. Your individual response depends on multiple factors: your baseline weight, sleep quality, stress levels, what other medications you're taking, and—critically—your diet and activity habits.

The most practical approach is to track your weight and appetite for the first 8-12 weeks after starting bupropion. If your trend isn't heading where you want it, that's a conversation to have with your prescriber about options. They may adjust your treatment plan or consider alternatives.

What won't change regardless of medication: the fundamentals of nutrition still apply. Prioritizing protein, fiber, and minimally processed foods supports both mental health and weight management. Our GLP-1 diet guide covers nutrition strategies that work well alongside any weight-related medication.

How Contrave Is Different

If weight loss is your primary goal, there's a medication that's actually designed for it: Contrave. This combines naltrexone (an opioid receptor blocker) with bupropion in a specific formulation that's FDA-approved for chronic weight management.

The clinical trial data for Contrave is more impressive than bupropion alone. In 56-week studies, patients taking Contrave alongside diet and exercise lost an average of 5-9% of their body weight, compared to 1-5% with placebo—meaning the medication contributed roughly 4-5 percentage points of additional weight loss.^4,5 About 46% of patients on Contrave achieved at least 5% weight loss by week 16.⁶

The dosing requires gradual titration over four weeks, building up to two tablets twice daily. Like any medication, Contrave has side effects—nausea is the most common—and it's not appropriate for everyone. But for people who qualify, it represents a legitimate pharmacological tool for weight management that bupropion alone doesn't provide.

Make Nutrition Easier While You Figure Out Medications

Whether you're starting an antidepressant, considering Contrave, or simply trying to eat better, consistency in your nutrition matters more than perfection. Hitting your protein and calorie targets becomes much simpler when you're not starting from scratch every day.

Our Weight Loss Meal Plan takes the guesswork out of portion control and macros. Or build your own plan to match your specific preferences and goals.

Frequently Asked Questions

Does Wellbutrin usually cause weight loss?

Not usually. On average, bupropion is linked to the least weight gain among common antidepressants, and some people lose a small amount—but results vary widely from person to person.

Is Contrave the same as Wellbutrin?

No. Contrave is a fixed combination of naltrexone plus bupropion, specifically FDA-approved for chronic weight management when combined with lifestyle changes. Wellbutrin (bupropion alone) is approved for depression and seasonal affective disorder, not weight loss.

Is Wellbutrin safe for someone with an eating disorder?

No. Bupropion is contraindicated in people with bulimia or anorexia nervosa due to increased seizure risk. Talk with your prescriber about alternative medications.

How much weight can you lose on Contrave?

In 56-week clinical trials, patients taking Contrave with diet and exercise lost an average of 5-9% of their body weight, compared to 1-5% with placebo. About 46% of patients on Contrave achieved at least 5% weight loss at 16 weeks.⁶

References

1. Petimar J, Young JG, Yu H, et al. Medication-induced weight change across common antidepressant treatments: a target trial emulation study. Ann Intern Med. 2024;177(8):993-1003. doi:10.7326/M23-2742

2. Harvard Health Publishing. Weighing in on weight gain from antidepressants. August 2024. https://www.health.harvard.edu/blog/weighing-in-on-weight-gain-from-antidepressants

3. CONTRAVE (naltrexone HCl and bupropion HCl) [prescribing information]. Currax Pharmaceuticals LLC.

4. Greenway FL, Fujioka K, Plodkowski RA, et al. Effect of naltrexone plus bupropion on weight loss in overweight and obese adults (COR-I): a multicentre, randomised, double-blind, placebo-controlled, phase 3 trial. Lancet. 2010;376(9741):595-605.

5. Apovian CM, Aronne L, Rubino D, et al. A randomized, phase 3 trial of naltrexone SR/bupropion SR on weight and obesity-related risk factors (COR-II). Obesity. 2013;21(5):935-943.

6. Halseth A, Shan K, Walsh B, Gilder K, Fujioka K. Method-of-use study of naltrexone sustained release (SR)/bupropion SR on body weight in individuals with obesity. Obesity. 2017;25:338-345.

Related reads: Best Supplements for Weight Loss · GLP-1 Diet Guide · Breakfast Ideas for Weight Loss