Everything You Need to Know About Antidepressants That Cause Weight Gain

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.

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.