Does Wellbutrin XL/SR cause weight gain or loss

Bupropion increases the level of the brain chemical dopamine. Some studies suggest that lower levels of dopamine may be linked to obesity.

Everything You Need to Know About Antidepressants That Cause Weight Gain

Weight gain is a possible side effect of many antidepressant drugs. While each person responds to antidepressant treatment differently, the following antidepressants may be more likely to cause weight gain during your treatment.

Tricyclic antidepressants, also known as cyclic antidepressants or TCAs, may cause weight gain. These drugs include:

amitriptyline (Elavil)
amoxapine
desipramine (Norpramin)
doxepin (Adapin)
imipramine (Tofranil-PM)
nortriptyline (Pamelor)
protriptyline (Vivactil)
trimipramine (Surmontil)

TCAs were some of the first drugs approved to treat depression. They aren’t prescribed as often anymore because newer treatments cause fewer side effects.

Weight gain was a common reason people stopped treatment with these types of antidepressants, according to a 1984 study.

Still, TCAs can be effective in people who don’t respond to other types of antidepressant drugs, despite the unwanted side effects.

Administrative costs currently make up a major chunk of healthcare spending, especially in America. In fact, healthcare administrative spending accounts for 8% of the GDP in the U.S., or more than $1.485 trillion if looking at 2016 data. The cost of healthcare administration in other nations is just 3% of the GPD, on average, according to healthcare revenue news source RevCycleIntelligence.

Monoamine oxidase inhibitors (MAOIs) were the first class of antidepressants to be developed. MAOIs that cause weight gain include:

phenelzine (Nardil)
isocarboxazid (Marplan)
tranylcypromine (Parnate)

Doctors prescribe MAOIs most often when other antidepressants don’t work due to certain side effects and safety concerns. Of the three MAOIs listed above, phenelzine is the most likely to result in weight gain, according to a 1988 review .

However, a newer formulation of an MAOI known as selegiline (Emsam) has been shown to result in weight loss during treatment. Emsam is a transdermal medication that’s applied to the skin with a patch.

SSRIs are the most commonly prescribed class of depression drugs. Long-term use of the following SSRIs may cause weight gain:

paroxetine (Paxil, Pexeva, Brisdelle)
sertraline (Zoloft)
fluoxetine (Prozac)
citalopram (Celexa)

Although some SSRIs are associated with weight loss at first, long-term use of SSRIs is mostly linked to weight gain. Long-term use is considered treatment that lasts longer than six months.

Of the SSRIs listed above, paroxetine is most commonly associated with weight gain with both long-term and short-term use.

Mirtazapine (Remeron) is a noradrenergic antagonist, which is a type of atypical antidepressant. The drug has been shown repeatedly to be more likely to cause weight gain and to increase appetite than other drugs.

Mirtazapine is less likely to make people gain weight compared with TCAs.

It also doesn’t result in as many other side effects as other antidepressants. However, it can cause:

nausea
vomiting
sexual dysfunction

Other antidepressants have been associated with less weight gain as a side effect. These antidepressants include:

escitalopram (Lexapro, Cipralex), an SSRI
duloxetine (Cymbalta), a serotonin-norepinephrine reuptake inhibitor (SNRI), may cause modest weight gain with long-term use
bupropion (Wellbutrin, Forfivo, and Aplenzin), an atypical antidepressant
nefazodone (Serzone), a serotonin antagonist and reuptake inhibitor
venlafaxine (Effexor) and venlafaxine ER (Effexor XR), which are both SNRIs
desvenlafaxine (Pristiq), an SNRI
levomilnacipran (Fetzima), an SNRI
vilazodone (Viibryd), a serotonergic antidepressant
vortioxetine (Trintellix), an atypical antidepressant
selegiline (Emsam), a newer MAOI that you apply to your skin, which may lead to fewer side effects than MAOIs taken by mouth

Weight gain is also less likely to occur with the following SSRIs when they’re used for less than six months:

sertraline (Zoloft)
fluoxetine (Prozac)
citalopram (Celexa)

Not everyone taking an antidepressant will gain weight. Some people will actually lose weight.

Experts emphasize that worries about gaining weight shouldn’t influence the choice of antidepressant for most people. There are other side effects and factors to consider when choosing an antidepressant.

If you do gain some weight while taking an antidepressant, the drug may not actually be the direct cause of the weight gain. An improved mood while taking an antidepressant, for example, may increase your appetite, leading to weight gain.

Don’t stop taking your drug right away even if you do gain a little bit of weight. You’ll need to work with your doctor to find an antidepressant that helps with your depression symptoms and doesn’t result in unwanted side effects. This may take a little bit of patience.

Your doctor can also give you some tips for preventing weight gain while on antidepressant therapy.

Last medically reviewed on April 18, 2019

How we reviewed this article:

Healthline has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references. You can learn more about how we ensure our content is accurate and current by reading our editorial policy.

Berken GH, et al. (1984). Weight gain. A side-effect of tricyclic antidepressants [Abstract]. DOI:
10.1016/0165-0327(84)90031-4
Cantu TG, et al. (1988). Monoamine oxidase inhibitors and weight gain [Abstract].
ncbi.nlm.nih.gov/pubmed/3068037
Highlights of prescribing information: Emsam (selegiline transdermal system). (2015).
emsam.com/en/prescribing-information
Highlights of prescribing information: Trintellix (vortioxetine) tablets, for oral use. (2018).
general.takedapharm.com/TRINTELLIXPI
Ferguson JM. (2001). SSRI antidepressant medications: Adverse effects and tolerability.
ncbi.nlm.nih.gov/pmc/articles/PMC181155/
Gartlehner G, et al. (2011). Comparative benefits and harms of second-generation antidepressants for treating major depressive disorder: An updated meta-analysis. DOI:
10.7326/0003-4819-155-11-201112060-00009
Label: Doxepin hydrochloride capsule. (2015).
dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=1533343b-f1ed-4c3a-bb36-23a748452b05
Label: Mirtazapine tablet, film coated. (2017).
dailymed.nlm.nih.gov/dailymed/drugInfo.cfm?setid=aecec663-16ed-4c34-a00a-af6b99b3e1b6
Mayo Clinic Staff. (2016). Tricyclic antidepressants and tetracyclic antidepressants.
mayoclinic.org/diseases-conditions/depression/in-depth/antidepressants/ART-20046983
Serretti A, et al. (2010). Antidepressants and body weight: A comprehensive review and meta-analysis [Abstract].
ncbi.nlm.nih.gov/pubmed/21062615
Uher R, et al. (2011) Changes in body weight during pharmacological treatment of depression. DOI:
10.1017/S1461145710000933
Watanabe N, et al. (2011). Mirtazapine versus other antidepressive agents for depression. DOI:
10.1002/14651858.CD006528.pub2
Wise TN, et al. (2006). Effects of the antidepressant duloxetine on body weight: Analyses of 10 clinical studies.
ncbi.nlm.nih.gov/pmc/articles/PMC1764530/

Does Wellbutrin XL/SR cause weight gain or loss?

Medically reviewed by Sally Chao, MD. Last updated on April 6, 2023.

Official answer

by Drugs.com

Wellbutrin XL and Wellbutrin SR are different formulations of the antidepressant bupropion. Both Wellbutrin XL and Wellbutrin SR may cause weight gain or weight loss, but weight loss is more common. Not everyone taking these drugs will experience a change in weight.

Weight changes are considered a side effect for both Wellbutrin XL and Wellbutrin SR. Studies of Wellbutrin XL show that 23% of people taking a dose of 150 to 300 mg per day lost 5 pounds or more. In the same studies, 11% of people gained more than 5 pounds.

Studies of Wellbutrin SR show that 14% of people taking a dose of 300 mg per day lost more than 5 pounds. At a dose of 400 mg, 19% of people lost more than 5 pounds. In the same studies, a small percentage of people gained more than 5 pounds: 3% taking 300 mg and 2% taking 400 mg.

Bupropion may also be used to help people stop smoking. A study of sustained-release (SR) bupropion for smoking cessation found that people using this medication were less likely to gain weight after they stopped smoking.

The reason bupropion causes some people to lose weight is not known, but it may have to do with its mechanism of action to treat depression.

Bupropion increases the level of the brain chemical dopamine. Some studies suggest that lower levels of dopamine may be linked to obesity.

The difference between Wellbutrin XL and Wellbutrin SR lies in the dosing schedule. XL is an extended-release medication and only needs to be taken once a day. SR stands for sustained release, and it may be taken twice a day.

Both XL and SR formulations are approved to treat major depressive disorder. Wellbutrin XL has an additional approval for seasonal affective disorder (SAD), which is depression that occurs with the changing of seasons, usually in the fall and winter.

Food and Drug Administration (FDA). Wellbutrin XL Prescribing Information. May 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/021515s036lbl.pdf. [Accessed March 2, 2021].
Food and Drug Administration (FDA). Wellbutrin SR Prescribing Information. October 2020. Available at: https://gskpro.com/content/dam/global/hcpportal/en_US/Prescribing_Information/Wellbutrin_SR/pdf/WELLBUTRIN-SR-PI-MG.PDF. [Accessed March 2, 2021].
Anderson JW, Greenway FL, Gadde KM, et al. Bupropion SR Enhances Weight Loss: A 48-Week Double-Blind, Placebo-Controlled Trial. Obes Res. 2002;10:633-641. https://onlinelibrary.wiley.com/doi/full/10.1038/oby.2002.86. [Accessed March 2, 2021].

Drug information

Related support groups

Wellbutrin XL (86 questions, 393 members)
Wellbutrin (367 questions, 1,511 members)
Weight Loss (Obesity/Overweight) (693 questions, 1,423 members)
Weight Loss (Underweight) (14 questions, 823 members)

Does Wellbutrin XL/SR cause weight gain or loss