Medically reviewed by Katelyn Hagerty, FNP
Written by Our Editorial Team
Last updated 7/3/2022
Depression is a common mental illness that can occur in people of all ages and backgrounds. In fact, data from the 2020 National Survey on Drug Use and Health suggest that an estimated 8.4 percent of US adults, including 10.5 percent of adult women, suffer from depression annually.
If you’ve been diagnosed with depression, your healthcare provider may prescribe a medication called Wellbutrin® to improve your mood and control your depressive symptoms.
Does Wellbutrin cause weight gain? Weight gain is a common side effect of several medications for depression. However, Wellbutrin differs from many antidepressants in that research suggests that it isn’t likely to cause weight gain and that it can in fact often contribute to weight loss.
Below, we’ve explained what Wellbutrin is, as well as how it works as a treatment for depression in women.
We’ve also discussed the relationship between Wellbutrin and your weight, as well as other side effects to be aware of before using Wellbutrin to treat depression.
Wellbutrin is an antidepressant that contains the active ingredient bupropion. It was approved by the Food and Drug Administration (FDA) in 1985 and is widely used to treat major depressive disorder (MDD, or depression).
Unlike most widely-used antidepressants, bupropion isn’t a selective serotonin reuptake inhibitor (SSRI). Instead, it belongs to a class of drugs referred to as “atypical” antidepressants due to its unusual mechanism of action.
Most antidepressants work by stopping the reuptake of serotonin, which can increase serotonin levels in your brain and body.
Serotonin is a naturally-occurring chemical referred to as a neurotransmitter. It’s involved in the regulation of your moods, happiness and feelings of anxiety. Experts believe that low serotonin levels play a key role in the development of the symptoms of depression.
Instead of targeting serotonin, Wellbutrin works by increasing levels of other neurotransmitters, such as norepinephrine and dopamine.
Norepinephrine is a neurotransmitter that helps to regulate your heart rate, blood pressure and blood sugar levels. Low levels of norepinephrine are associated with lethargy, poor focus and a higher risk of developing depression, anxiety or post-traumatic stress disorder (PTSD).
Dopamine is a monoamine neurotransmitter that’s involved in other aspects of mental function, including reward-seeking behavior.
There’s also evidence that Wellbutrin targets receptors that respond to nicotine. Bupropion, the active ingredient in Wellbutrin, is also sold as a medication for quitting smoking and as a treatment for seasonal affective disorder (SAD).
Many antidepressants have a reputation for causing weight gain. While study findings vary from one drug to another, this reputation is somewhat deserved, as many antidepressants are linked to changes in appetite and body weight.
For example, a population-based cohort study published in the BMJ in 2018 found that people who use antidepressants were more likely to gain weight over the course of several years than their peers.
However, not all types of antidepressant medication are associated with a higher risk of weight gain.
Most studies of antidepressants and weight gain involve widely-used classes of antidepressant drugs, such as selective serotonin reuptake inhibitors (SSRIs), tricyclic antidepressants (TCAs) and monoamine oxidase inhibitor medications (MAOIs).
As an atypical antidepressant, bupropion isn’t associated with the same risk of changes in body mass as other medications for depression.
In fact, some clinical trials of bupropion have found that it’s more likely to cause mild weight loss than adverse weight gain.
In a clinical trial published in the journal Obesity Research, a team of researchers looked at the effects of bupropion on the average body weight of obese people.
A total of 327 people participated in the trial, with just under 200 finishing 48 weeks. One group was counseled on energy-restricted diets, meal replacement and exercise, while the other also received counseling but was also instructed to take a daily dose of bupropion.
Over the course of 24 weeks, the researchers found that the people who used bupropion were more likely to achieve weight loss, with an average weight loss of 7.2 percent and 10.1 percent in people who received 300mg or 400mg of bupropion per day.
After 48 weeks, the people that received bupropion showed sustained weight loss, suggesting that bupropion may cause lasting changes in eating habits and body weight.
Other studies have produced similar findings. For example, a smaller-scale clinical trial, which was also published in the journal Obesity Research in 2001, found that overweight and obese people who used bupropion lost more weight than people who received a placebo.
More recent research suggests that a combination of bupropion and naltrexone, a medication that’s typically used to treat alcohol or opioid use disorders, helps to induce weight loss when combined with calorie restriction and physical activity.
In general, there’s very little evidence that bupropion, whether it’s sold as Wellbutrin or under any other brand name, is associated with weight gain. For the most part, studies suggest the opposite — that bupropion typically causes a mild amount of weight loss.
Although Wellbutrin isn’t as closely associated with weight gain as other antidepressants, it can still cause adverse effects.
Common side effects of Wellbutrin include:
Nausea and/or vomiting
Headache and/or migraine
Insomnia (difficulty falling asleep)
Sedation and drowsiness
Tachycardia (fast heart rate)
Changes in appetite
Blood pressure changes
Wellbutrin is generally less likely to cause sexual issues than other antidepressants. However, a small percentage of people who use bupropion still report sexual dysfunction issues such as low sex drive and, in men, erectile dysfunction (ED). For details, we have a blog on Wellbutrin sexual side effects.
Like other antidepressants, Wellbutrin can cause withdrawal effects when it’s stopped suddenly, making it important to inform your healthcare provider if you’re prescribed Wellbutrin and plan to stop using your medication.
Some side effects of Wellbutrin may be transient, meaning they’ll gradually become less severe as your body gets used to the effects of the medication.
If you’re prescribed Wellbutrin and notice any of the side effects above, it’s important to tell your healthcare provider. They may adjust your dosage of Wellbutrin, suggest changing the way you use your medication or switching to a different antidepressant.
Wellbutrin is a popular antidepressant that’s typically used to treat major depression. Bupropion, its active ingredient, is also used to treat seasonal affective disorder, and as an aid for reducing nicotine cravings and helping with smoking cessation.
Unlike other antidepressants, bupropion isn’t associated with weight gain. Instead, most studies suggest that it may cause a small amount of weight loss over the long term.
If you’re prescribed bupropion and notice your weight changing more than you’d like, talk to your healthcare provider. They may suggest making changes to your diet and habits or adjusting the way you use your medication.
Finally, you can learn more about successfully coping with depression, anxiety, stress and other common mental health issues using our free mental health resources and content.