Does Wellbutrin cause weight gain or loss?

Does Wellbutrin cause weight gain?

For most people, no, Wellbutrin does not cause weight gain. Wellbutrin (bupropion) is among the least likely of antidepressants to cause weight gain. In fact, many people find their weight stays the same or drops slightly.

A 2024 study followed more than 180,000 adults for up to two years and found that people who started bupropion gained less weight than those taking seven other common antidepressants. Overall, they were about 15 percent less likely to gain a clinically meaningful amount of weight (defined as 5 percent or more of their body weight) than people taking sertraline, the most-prescribed option.

That said, everyone responds to medication differently, and some people do gain weight. Whether that’s a side effect of the medication or an improvement in symptoms leading to improved appetite is less clear. Still, the differences tend to be small.

In clinical trials, most people’s weight stayed within a few pounds either way. In the short-term trials of patients taking it for depression, about 14 percent of people on a standard 300mg dose lost five pounds or more, while gaining five pounds or more was less likely (3 percent of people) and about the same as the placebo group (4 percent of people). Bigger shifts in either direction were the exception.

Does the formulation or dose matter?

Wellbutrin comes in immediate-release (IR), sustained-release (SR), and extended-release (XL). The formulation changes how often you take it, but it’s not likely to change how much weight you gain.

The dose seems to matter more. In clinical trials for Wellbutrin SR, about 14 percent of people lost five pounds or more at the standard 300 mg dose. Slightly more people (about 19 percent) lost that same amount at 400 mg. The approved labeling for the medication describes this as a dose-related decrease in body weight.

Why do some people gain weight on Wellbutrin?

For those who do gain weight on Wellbutrin, it’s not always clear that it’s a side effect of the medication. “Weight gain is quite rare, as patients usually stay weight stable, or maybe lose a little weight if they experience appetite suppression,” says Kate Hanselman, PMHNP, VP of clinical psychiatry at Thriveworks. “It’s usually going to be tied to a return of someone’s appetite if a reduced appetite was a symptom of their depression.”

Many people struggling with depression notice a change in their eating habits, so it tracks that managing depression may come with a return of your appetite. That’s a positive sign, but it may lead to weight gain for some people.

While weight gain tends to be modest, talk to your prescriber if you are concerned. They can help determine the next best steps. “Switching can be helpful if necessary, but we’d need to know the specific reason for the weight gain before making changes,” Hanselman says.

How Wellbutrin compares to other antidepressants

Weight gain isn’t unique to any one antidepressant, but the odds differ from drug to drug. A 2024 analysis compared eight common first-line antidepressants to sertraline (Zoloft), the most commonly prescribed antidepressant in the study. Here’s how they ranked on average weight change over six months, compared with sertraline, (which led to an average increase of 0.5 pounds after six months).

Source: Medication-Induced Weight Change Across Common Antidepressant Treatments. Annals of Internal Medicine (2024)

Overall, those taking Wellbutrin were about 15 percent less likely to gain at least five percent of their body weight than those taking sertraline.

Why Wellbutrin affects weight differently

Unlike many of the most commonly used antidepressants, Wellbutrin works on dopamine and norepinephrine. Why it affects weight differently isn’t entirely clear, though, and there is likely more than one reason.

The most widely-cited reason researchers think Wellbutrin may affect weight differently than most other antidepressants has to do with dopamine’s effects on appetite. Dopamine is a neurotransmitter that plays a key role in appetite as well as the emotional drive to eat.

Because it has little effect on serotonin, Wellbutrin is less likely than many other antidepressants to cause sexual side effects like reduced libido or difficulty reaching orgasm. These are relatively common with SSRIs and a frequent reason people stop taking them. The trade-off is that Wellbutrin tends to be activating. It’s more likely to cause insomnia, jitteriness, or a small rise in blood pressure, and less likely to leave you feeling sedated.

Does Wellbutrin cause weight loss?

Wellbutrin can cause weight loss, but not dramatically. When weight loss happens, it’s typically only a few pounds, and it’s more likely for those who start at a higher weight and take higher doses.

It’s important to note that Wellbutrin isn’t a weight-loss drug, and it isn’t FDA approved for that purpose. However, there is an FDA-approved weight loss medication called Contrave, which is a combination of naltrexone and bupropion (the ingredient in Wellbutrin). But, on its own, Wellbutrin’s effect on weight is much smaller.

Can Wellbutrin be used off-label for weight loss?

While Wellbutrin may rarely be prescribed off-label for weight loss, it’s not considered to be a substitute for medications actually designed for weight loss. It doesn’t generally lead to much weight loss, even at the highest approved doses. Where Wellbutrin is most helpful is when you’re looking for an antidepressant that is less likely to lead to weight gain.

Why Wellbutrin isn’t prescribed if you have an eating disorder

Wellbutrin is not recommended if you have a current or past diagnosis of anorexia nervosa or bulimia. That’s because people with these conditions had a higher incidence of seizures in early studies on the medication. Research suggests that electrolyte changes caused by purging or restricting can increase seizure risk, which is thought to compound the seizure risk with Wellbutrin.

“We assess thoroughly to ensure we have a full picture of each patient’s experience, which includes ruling in and out various diagnoses,” Hanselman explains. “We should be aware of any disordered eating or body dysmorphia that would make Wellbutrin a less suitable choice.”

This is also why a prescriber may pause if someone asks for Wellbutrin specifically to suppress appetite or lose weight; if disordered eating is part of the picture, Wellbutrin is the wrong tool, and there are safer, more effective ways to get support.

“If a patient is looking for weight loss support, I recommend that they access care through a weight loss specialist so they can receive specialist care,” Hanselman says.

What to do if your weight changes on Wellbutrin

Some fluctuation is normal, especially in the first few months as your body and appetite adjust. It’s worth checking in with your prescriber if you experience rapid weight loss, if it’s bothersome, or if it’s affecting your health. They can help determine if it may be due to the medication, an improvement in your depression, or other shifts in your life. Based on that, you can have a conversation about next steps, whether that means adjusting the dosage or considering alternative medications.

“We will have monthly visits at first, and we’re tracking weight at each visit,” Hanselman says. “Weight loss shouldn’t happen to such an extreme extent within that interval as a side effect of Wellbutrin, so if we see any significant amount of weight change between visits I’d explore underlying reasons as well.”

The bottom line

Wellbutrin is one of the antidepressants least associated with weight gain. Most people stay about the same or lose a little, but when weight does change, it’s usually only a few pounds.

However, Wellbutrin is not a weight loss medication, and it’s not recommended if you have a current or past eating disorder. It’s always smart to check in with your prescriber if you experience rapid or bothersome weight changes while taking Wellbutrin.

Frequently asked questions (FAQs)

Are you more likely to lose or gain weight on Wellbutrin?

You’re more likely to stay about the same or lose a little weight. Wellbutrin is among the antidepressants least likely to cause weight gain, and studies show more people lose weight than gain it. Still, weight changes tend to only be a few pounds in either direction.

Does Wellbutrin suppress appetite?

It can, for some people. Because Wellbutrin works on dopamine and norepinephrine, it can lead to a mild reduction in appetite. The effect is usually modest, though, and not everyone notices it.

How much weight do you lose on Wellbutrin?

Usually not much. It’s often just a few pounds, if any. Weight loss is most likely early in treatment and in people who start at a higher weight or take higher doses.

Why am I gaining weight on Wellbutrin?

It’s not clear why, but for some people it may be a sign of appetite returning as depression improves. Individual biology, other medications, and lifestyle changes also play a role. It’s worth discussing it with your prescriber, though, who can help sort out the cause and whether any change is needed.

Can I ask my doctor for Wellbutrin to lose weight?

Wellbutrin is not recommended for weight loss. If weight is your main concern, they can point you toward medications actually designed for it, including the bupropion-naltrexone combination (Contrave). Bupropion also isn’t recommended if you have a current or past eating disorder. If you are looking for a weight loss medication, a good place to start is a conversation with your provider about your options.

Can you take Wellbutrin with a GLP-1?

Generally, yes. There’s no known interaction between Wellbutrin and GLP-1 medications like semaglutide (Ozempic, Wegovy), and they may sometimes be prescribed together; for example, semaglutide for weight loss and Wellbutrin for depression. Your provider can help determine if each medication is right for you.