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Which antidepressants cause weight loss?

Learn how antidepressants such as Wellbutrin, Prozac, and Effexor may contribute to weight loss
Gerardo Sison medical writer headshot
By | Updated on Oct. 23, 2024 Medically reviewed by Kristi C. Torres, Pharm.D.
Rx pill bottles with floating pills: Which antidepressants cause weight loss?

Key takeaways

  • There are a variety of antidepressants available, and the way each type interacts with your body is different. Some may be more prone to cause weight gain, while others may be associated with weight loss or have no effect on weight at all.

  • Older antidepressants such as tricyclic antidepressants and monoamine oxidase inhibitors are most likely to be associated with weight gain.

  • There are some antidepressants that have been associated with weight loss such as Prozac (fluoxetine) and Effexor XR (venlafaxine), but they have not been approved by the FDA to be used for weight loss.

  • Antidepressants have side effects other than weight changes. For this reason, it is not recommended to utilize antidepressants for the purpose of weight loss alone.

  • If you are seeking treatment for depressive symptoms and weight control is a concern, speak with your healthcare provider about these concerns so that the drug choice aligns with your concerns about weight.

In this article:

When it comes to managing depression, finding the right antidepressant can be a complex process. People may experience depression symptom changes and medication side effects in different ways. One particularly sensitive side effect is weight change while taking antidepressants.

Although weight gain is common with many types of antidepressants, there are some options available that have been shown to be less likely to cause this outcome. Generally speaking, older antidepressants such as tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) are most notorious for causing weight gain. Some of the newer antidepressants that work through serotonin, norepinephrine, and dopamine modulation are known to have a lower risk of weight gain and may even contribute to weight loss. A few of the options tied to weight loss include Wellbutrin (bupropion), Prozac (fluoxetine), and Effexor (venlafaxine), 

As with all medications, it’s important to consult a healthcare provider to find the most appropriate option for your specific needs and concerns. Continue reading to explore some antidepressant options that may contribute to weight loss.

Can antidepressants cause weight loss?

Serotonin is a chemical or neurotransmitter that can play a role in regulating metabolism and appetite control in addition to mood, sleep, and other bodily functions. Some of the most widely used antidepressants, selective serotonin reuptake inhibitors (SSRIs), affect how serotonin is transported in the brain. This can affect both short-term and long-term weight changes that are different for every person. 

While many antidepressants affect serotonin levels, others may work through neurotransmitters, such as dopamine and norepinephrine. Effects on these pathways may cause weight loss instead of weight gain. For example, although the way in which bupropion causes weight loss is not fully understood, its effects on dopamine and norepinephrine may play a role in promoting weight loss. It is important to remember that other factors such as lifestyle, diet, and exercise can influence weight management while taking antidepressant medications. 

Which antidepressants cause weight loss?

Certain antidepressants from various drug classes have been shown to potentially cause weight loss. However, weight loss associated with these medications may be a short-term effect and could change with long-term use. 

Prozac (fluoxetine)

Fluoxetine is an SSRI that has been linked to weight loss. It works by increasing serotonin levels in the brain, which may help improve mood and regulate appetite, leading to weight loss. Studies have shown that fluoxetine may reduce body weight by around three kilograms when used off-label in people who are overweight or obese. Common dosages of fluoxetine range from 20 to 80 mg per day, depending on the severity of depression and the patient’s response to treatment. Weight loss may be more significant at higher doses of fluoxetine, but adverse events are more likely at these doses as well. These include dizziness, drowsiness, insomnia, or nausea.

Related: Prozac side effects

Wellbutrin (bupropion)

Bupropion is a norepinephrine-dopamine reuptake inhibitor (NDRI), which is another type of antidepressant medication that may be linked to weight loss. Bupropion works by increasing the levels of norepinephrine and dopamine in the brain. It has the most studies connecting it to weight loss among antidepressants. Common dosages of bupropion range from 150 to 450 mg per day, depending on the specific formulation and the person’s overall condition.

Related: Wellbutrin for weight loss

Effexor XR (venlafaxine)

Venlafaxine is a serotonin-norepinephrine reuptake inhibitor (SNRI) that has been associated with weight loss in some cases. It works by increasing both serotonin and norepinephrine levels in the brain. The weight-loss effects of venlafaxine generally occur when first starting treatment, and weight gain may occur with long-term treatment. Common doses of venlafaxine range from 37.5 to 225 mg per day, depending on the severity of the symptoms and the patient’s response to treatment.

Cymbalta (duloxetine)

Duloxetine is another SNRI that has been linked to both weight loss and weight gain in individuals. Similar to venlafaxine, it works by increasing serotonin and norepinephrine levels in the brain. Studies have shown that duloxetine may cause weight loss within the first eight to nine weeks of treatment. However, people on long-term treatment with duloxetine for at least a year may experience weight gain. Common doses of duloxetine range from 30 to 120 mg per day, depending on the specific condition being treated and the patient’s response to therapy.

Related: Cymbalta side effects

Antidepressants for weight loss
Drug name Drug class Savings options
Prozac 

(fluoxetine)

 SSRI See latest prices
Wellbutrin XL 

(bupropion ER)

 NDRI See latest prices
Effexor XR 

(venlafaxine ER)

 SNRI See latest prices
Cymbalta 

(duloxetine)

 SNRI See latest prices

The effects of these prescription medications on weight loss can vary. You should discuss possible side effects, appropriate dosages, and other concerns with your healthcare provider before starting a new medication.

Can you take antidepressants for weight loss?

While some antidepressants have been linked to weight loss, they are only FDA approved for the treatment of major depressive disorder and other mental health disorders at this time. Using antidepressants solely for weight loss purposes is not recommended, as they may not be appropriate for every individual and can have potential side effects. 

If you’re interested in weight-loss medications, you should consult your primary care provider or a specialist to determine the best option for you. If you’re struggling with symptoms of depression and are also concerned about weight gain as a side effect, a healthcare provider may recommend an antidepressant that has a low risk of weight gain. Healthcare providers may also recommend other weight-loss methods, such as lifestyle changes or supervised weight-loss programs. 

Consult your healthcare provider for medical advice. You should not start, stop, or change the dosage of any medication without discussing it with your healthcare provider first.

Risks of using antidepressants to lose weight

While weight loss may be a potential side effect of some antidepressants, other possible risks and side effects can also develop while using these medications. For example, one common side effect of certain antidepressants is sexual dysfunction, which can occur as a decrease in libido, difficulty achieving or maintaining an erection, or issues with reaching orgasm. 

Antidepressants can also lead to changes in blood pressure, either high or low, depending on the individual and the medication. People with an underlying condition that affects their blood pressure may need to be cautious and closely monitored when starting a new antidepressant.

Other potential side effects of antidepressants can include:

  • Nausea
  • Headaches
  • Insomnia
  • Dry mouth
  • Fatigue
  • Dizziness

Serious side effects of antidepressants may include increased suicidal thoughts or behaviors, serotonin syndrome, and allergic reactions. Seek immediate medical help if you experience signs or symptoms that may indicate a serious problem. 

The side effects of antidepressants can differ between the different types and individuals. The severity and duration of these side effects may vary. However, common side effects usually disappear over time as the body adjusts to the medication.

How to maximize the benefits of antidepressants for weight loss

There are different ways to manage weight while taking antidepressants, especially if you’re concerned about weight gain. The following are some healthy tips that can be used along with your treatment plan to manage weight.

Incorporate regular exercise or physical activity

Regular exercise with an active lifestyle may help support weight loss efforts in those taking antidepressants. Clinical studies have shown that increased physical activity is one of the cornerstones of weight control in people with depression. Create an exercise plan that includes a mix of aerobic exercises and strength training for calorie burning and muscle development.

Manage appetite and food intake with a healthy diet

You may be able to manage weight while on antidepressants with a balanced diet. You may want to pay attention to portion sizes and choose nutrient-dense foods, such as whole grains, fruits, lean proteins, and vegetables. Reducing calorie intake and eating a healthy diet may help manage appetite, improve energy levels, and support your overall goals.

Reduce stress

Reducing stress may be helpful in managing weight while taking antidepressants. Try using stress management techniques like deep breathing exercises, mindfulness meditation, muscle relaxation, or yoga every day. These practices may help lower stress levels, improve your mood, and support weight loss by helping you deal with emotional triggers and make healthier choices.

Be consistent with your weight loss efforts

Losing weight while on antidepressants can take time, so it’s important to stay consistent and patient. You may want to stick to your exercise routine, eat a healthy diet, and practice stress management techniques consistently. Losing weight slowly and steadily is healthier and longer-lasting than losing weight quickly. 

These are just some lifestyle changes that can help you manage antidepressant effects on weight. These daily habits may even help improve the potential for weight loss with certain antidepressants. 

Antidepressants that do not cause weight loss

While some antidepressants are known to cause weight loss, there are others that may cause weight gain or no changes in body weight. Let’s explore some of the antidepressants that are weight-neutral or cause some weight gain. 

Weight-neutral antidepressants

Antidepressants that are weight-neutral are not known to cause significant changes in body weight. These medications may be a better option for individuals concerned about unwanted weight changes. They may include antidepressants from different drug classes, including SSRIs, SNRIs, and atypical antidepressants. 

Weight-neutral antidepressants may include Trintellix (vortioxetine), Lexapro (escitalopram), and Pristiq (desvenlafaxine). These medications may cause small changes in weight, but the possibility of notable weight changes, including weight gain or weight loss, is low. 

Antidepressants that cause weight gain

Tricyclic antidepressants (TCAs) and monoamine oxidase inhibitors (MAOIs) are two types of antidepressant medications that may cause weight gain. Elavil (amitriptyline) and Pamelor (nortriptyline) have been linked to the greatest amount of weight gain among TCAs. 

Among the MAOIs, Nardil (phenelzine) causes the greatest amount of weight gain. One study found that patients taking phenelzine gained an average of almost seven to 10 kilograms. 

Some SSRI medications may cause weight gain or be considered weight-neutral. For example, Celexa (citalopram) is an SSRI that may cause weight gain, while Lexapro (escitalopram) is considered weight-neutral. In addition, certain atypical antidepressants, such as Remeron (mirtazapine), may cause weight gain. 

Antidepressants that don’t cause weight loss

Consult your doctor or healthcare provider to determine the best antidepressant for your specific needs. A healthcare provider may evaluate the severity of depression, overall health, and other factors when determining a medication to prescribe.