Which Antidepressants Cause Weight Gain? - GoodRx (2024)

Depression affected about 8% of U.S. adults in 2020. In fact, it's one of the most common mental health conditions worldwide. Depression treatment may involve psychotherapy or medications. Many people benefit from receiving both.

People who take antidepressant medications may wonder about their potential side effects. One concern may be the potential for antidepressants to cause weight gain. But, is Lexapro or Prozac really to blame for those extra pounds? Here, we’ll cover what you need to know about antidepressants and weight gain.

Do all antidepressants cause weight gain?

It’s possible for all antidepressants to cause weight gain, but some are more likely to cause it than others. And not everyone taking an antidepressant will gain weight. Overall, studies show that 10% to 20% of people taking antidepressants gain an average of 2 lbs to 7 lbs.

It’s likely that you’ll be able to find an antidepressant that helps your symptoms with little effect on your weight. It just might take a little trial and error to find the right fit.

Why do antidepressants cause weight gain?

Antidepressants act on several different chemicals and receptors (binding sites) in the body. And some of these effects can change the way your body responds to food.

Medications that block histamine receptors can lead to weight gain. You may recognize histamine as a chemical that causes allergy symptoms. But it also helps you control your appetite. Blocking it may increase your craving for carbs and make you feel less full than usual, leading you to eat more. Tricyclic antidepressants (TCAs) are most often associated with these effects.

Other antidepressants block a certain type of serotonin receptor that controls how much you eat. And some also increase levels of serotonin in the body, which can make you want to eat more than usual. These effects are often associated with selective serotonin reuptake inhibitors (SSRIs).

It’s also possible that weight gain from antidepressants may not actually be caused by the medication itself. Depression can cause a decreased appetite in some people. It can also make you feel less motivated to exercise, which can cause muscle loss.

Once your antidepressant starts to work, your appetite may return to normal. And you may also feel more motivated to exercise and rebuild any muscle you’ve lost. Both of these changes can lead to weight gain. But they’re also often a sign that your depression symptoms are improving.

Which antidepressants are commonly linked to weight gain?

As a class, TCAs are most likely to cause weight gain. Amitriptyline seems to be the biggest culprit within this class. Remeron (mirtazapine) is another antidepressant that’s more likely to cause weight gain than others. It’s a tetracyclic antidepressant that works in a similar way to TCAs in the body.

Most SSRIs are only linked to weight gain with long-term use. One exception to this is Paxil (paroxetine), which seems to cause weight gain both short-term and long-term. Another exception is Prozac (fluoxetine), which is more likely to be weight neutral (no weight gain or loss) with long-term use.

Which antidepressants are the least likely to cause weight gain?

Lexapro (escitalopram) and other SSRIs are less likely to cause weight gain if you take them for a short period of time (6 months or less). As mentioned, Prozac is the exception, since it doesn’t seem to cause weight gain in the long term.

As a class, the serotonin norepinephrine reuptake inhibitors (SNRIs) seem to cause the least amount of weight gain. This includes Effexor (venlafaxine) and Pristiq (desvenlafaxine). Cymbalta (duloxetine) is the SNRI most likely to cause weight gain with long-term use.

Wellbutrin (bupropion) is another antidepressant that’s least likely to cause weight gain. In fact, it’s often associated with weight loss in people who take it. So it’s often a preferred option for those looking to avoid weight gain from their depression medication.

The table below summarizes common antidepressants and their usual effect on body weight. Keep in mind that everyone responds to medication differently. Your experience may differ from what’s described below.

^short-term use
*long-term use

How can you manage or prevent weight gain from antidepressants?

If you’re living with depression, lifestyle changes can go a long way to help improve your symptoms and manage your weight at the same time. Regular exercise can help prevent weight gain and lift your mood. And a balanced diet that’s low in processed foods can keep your body fueled and running at its best.

If weight gain is a concern for you, discuss it with your healthcare provider before you start taking an antidepressant. They can help you choose an option that’s less likely to cause weight gain. If you’ve already started taking an antidepressant and you notice a change in your weight, let your provider know. They may want to change your depression medication. Or they may suggest adding a weight-loss medication if it’s appropriate for you.

Keep in mind: You shouldn’t stop taking your antidepressant without talking to your healthcare provider first. Many depression medications can cause harmful withdrawal symptoms if you stop taking them suddenly. Your provider can help you stop taking your medication safely, or give you directions for switching to a different medication if needed.