Do antidepressants cause weight loss?

Samir Kadri
Author: Samir Kadri Medical Reviewer: Morgan Blair Last updated:

Antidepressants are a widely used treatment across the United States for treating depression and other mental health conditions. However, these medications come with a range of side effects.

Although many antidepressants are thought to cause weight gain during long-term treatment, there are some that can lead to weight loss in patients.

Will I lose weight if I taking antidepressants?

Depression is commonly associated with low energy levels, and taking antidepressants may indirectly boost your energy levels as they better your mood.

However, side effects vary on a case-by-case basis. It’s important to emphasize that individual responses to medications can vary, and not everyone will experience weight loss while taking antidepressants.

For some people, any weight loss experienced after taking antidepressants will only be temporary. For others, short-term weight loss may be followed by weight gain.

Antidepressants associated with weight loss

Antidepressants that are associated with greater weight loss include:


Bupropion is an atypical antidepressant that is sometimes prescribed specifically for individuals who have experienced weight gain with other antidepressants. Multiple studies have shown it is effective in causing weight loss [1] [2].

As an atypical antidepressant, bupropion does not alter serotonin levels in the brain like many other antidepressants. Rather, it inhibits dopamine and noradrenaline reuptake. This unique mechanism of action could contribute to the weight loss it initiates in patients.

Bupropion, marketed as Wellbutrin, is not FDA-approved for weight loss. However, it may be prescribed off-label to that end.

A combination of naltrexone and bupropion, marketed under the brand name Contrave, is FDA-approved for treating obesity. If weight loss of 5% or more is not reported 12 weeks after treatment, the course of contrive ought to be discontinued and the patient re-evaluated. [3]

Fluoxetine (Prozac)

Fluoxetine is a selective serotonin reuptake inhibitor (SSRI) that is considered to have a more neutral or slightly weight-reducing effect compared to other SSRIs. [4]

Research shows that fluoxetine can cause weight loss of up to 2.7 kg compared with a placebo. However, this weight loss is associated with an increase in adverse effects such as nausea, insomnia, and dizziness. [4]

Whilst it can be a viable alternative to other SSRIs for managing weight gain, Prozac is not recommended exclusively as a weight loss treatment. Rather, eating a nutritious, balanced diet and a regular exercise regime are steps you can take to healthily lose weight.

Talk to your healthcare provider about the best strategies to deploy for losing weight.

How antidepressants cause weight loss

Some antidepressants affect neural pathways related to an individual’s appetite. [5] SSRIs work by increasing levels of serotonin in the brain. Serotonin plays a role in appetite regulation and can affect feelings of satiation following meals. Changes in serotonin levels can influence eating patterns and impact weight.

Depression can cause low energy levels in sufferers, affecting physical activity, eating patterns, and sleep habits. As antidepressants reduce symptoms of depression, these behaviors can improve causing weight loss in patients.

Bupropion has been associated with a slight increase in metabolic rate. [1] A faster metabolic rate means the body burns calories more efficiently, which may contribute to weight loss.

It must be noted that the decision to undergo a course of antidepressants should not solely be made on its potential impact on weight. The primary purpose of an antidepressant is to treat a patient’s depression or other mental health conditions.

Tips for preventing weight gain while taking antidepressants

If you have queries about preventing weight gain, discuss dietary and exercise regimes with your healthcare provider. Being intentional about your personal health whilst taking antidepressants can help with the treatment of depression.


Exercise can help mitigate the symptoms of depression, with patients encouraged to focus on the regularity of exercise sessions before increasing the intensity after the habit has been formed. [6]

Whether you are hoping to maintain weight, lose weight, reduce the risk of side effects related to weight fluctuation, or even gain weight, exercise is beneficial to you. [7] Walking, running, and strength-training can all be helpful.

The National Heart, Lung, and Blood Institute recommends 150 to 300 minutes of moderate-intensity activity a week, such as brisk walking. [8] People who seek to lose larger amounts of weight are advised to be physically active for over 300 minutes. [8]


Focus on consuming a variety of nutrient-dense foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats. Avoid excessive consumption of sugary and high-calorie processed foods.

Be mindful of portion sizes and avoid overeating. Pay attention to your body’s hunger and fullness cues, and try to avoid eating out of boredom or emotional reasons.

Drinking enough water can also help you feel full and reduce the likelihood of overeating. Sometimes, thirst can be mistaken for hunger.

When to contact a doctor

If you find any weight fluctuations concerning, contact your healthcare provider as soon as possible. They can amend your prescription and ensure you receive a more effective treatment plan.

If you experience serious weight loss whilst taking anti-depressants, call 911 immediately and get yourself to a hospital.

Final thoughts

Certain antidepressants can cause weight loss, usually temporary, in patients. However, none of these are FDA-approved for this purpose. Antidepressants ought to be taken to treat the condition they’ve been prescribed for – not for weight loss.

If you are considering taking antidepressants or are already on medication and are experiencing weight changes, it’s essential to discuss your concerns with your healthcare provider. They can provide guidance, monitor your progress, and adjust your treatment plan if necessary to find the most suitable medication for your specific needs.

Maintaining a healthy lifestyle, balanced diet, and regular exercise regime can be helpful in managing weight when on antidepressants.

  1. Fava, M., Rush, A. J., Thase, M. E., Clayton, A., Stahl, S. M., Pradko, J. F., & Johnston, J. A. (2005). 15 Years of Clinical Experience With Bupropion HCl. The Primary Care Companion to the Journal of Clinical Psychiatry, 07(03), 106–113.
  2. Gadde, K. M., Parker, C. B., Maner, L. G., Wagner, H. R., Logue, E. J., Drezner, M. K., & Krishnan, K. R. (2001). Bupropion for weight loss: an investigation of efficacy and tolerability in overweight and obese women. Obesity Research, 9(9), 544–551.
  3. Yanovski, S. Z., & Yanovski, J. A. (2015). Naltrexone Extended-Release Plus Bupropion Extended-Release for Treatment of Obesity. JAMA, 313(12), 1213.
  4. Serralde-Zuñiga, A. E., González-Garay, A. G., Rodríguez-Carmona, Y., & Meléndez-Mier, G. (2022). Use of Fluoxetine to Reduce Weight in Adults with Overweight or Obesity: Abridged Republication of the Cochrane Systematic Review. Obesity Facts, 15(4), 473–486.
  5. Mastronardi, C., Paz-Filho, G. J., Valdez, E., Maestre-Mesa, J., Licinio, J., & Wong, M-L. (2010). Long-term body weight outcomes of antidepressant–environment interactions. Molecular Psychiatry, 16(3), 265–272.
  6. Craft, L. L., & Perna, F. M. (2004). The Benefits of Exercise for the Clinically Depressed. Primary Care Companion to the Journal of Clinical Psychiatry, 6(3), 104–111.
  7. Swift, D. L., Johannsen, N. M., Lavie, C. J., Earnest, C. P., & Church, T. S. (2014). The Role of Exercise and Physical Activity in Weight Loss and Maintenance. Progress in Cardiovascular Diseases, 56(4), 441–447.
  8. hWhy Is Exercise Important? (n.d.).
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Samir Kadri
Author Samir Kadri Writer

Samir Kadri is a medical writer with a non-profit sector background, committed to raising awareness about mental health.

Published: Oct 18th 2023, Last edited: Oct 18th 2023

Morgan Blair
Medical Reviewer Morgan Blair MA, LPCC

Morgan Blair is a licensed therapist, writer and medical reviewer, holding a master’s degree in clinical mental health counseling from Northwestern University.

Content reviewed by a medical professional. Last reviewed: Oct 18th 2023