Antidepressants That Cause Weight Loss

Wellbutrin and Prozac Have Been Linked to Weight Loss

Antidepressants and weight

Verywell / Emily Roberts 

Many people with depression have worked hard to treat their disease by attending therapy and taking antidepressant medications. Among the side effects associated with antidepressants are both weight gain and weight loss, although these are not a side effect of every medication used to treat depression.

However, any side effect—including weight-related side effects—depends entirely on how your body reacts to a medication. It is possible that you will notice no change in weight or that you will swing in the opposite direction of what's typical, no matter which medication you take. For some people, the fluctuation in weight is only temporary.

Weight-Related Side Effects of Antidepressants

Weight changes are among the reported side effects of antidepressant drugs. While everyone's response is different, there are some antidepressants that are more associated with weight loss, while a few others have been linked to weight gain.

Antidepressants and Weight Loss

Antidepressants linked to weight loss include Prozac (fluoxetine) and Wellbutrin (bupropion). People taking Effexor (venlafaxine) may experience a quick loss of a small amount of weight, and in a 10-year-long study, Effexor was associated with below-average weight gain.

A link implies a statistical association, so it does not predict individual results. Put another way, these are antidepressants are associated with weight loss, but they are not antidepressants that cause weight loss every time. As well, sometimes weight-loss effects fade after a few months of antidepressant use.

Prozac is an SSRI. Effexor is a serotonin-norepinephrine reuptake inhibitor (SNRI). Wellbutrin is an atypical antidepressant that doesn't change serotonin levels in the brain. Rather, it uniquely alters other brain chemicals like noradrenaline and dopamine. This is associated not only with weight loss but also improved sexual functioning.

However, Wellbutrin may not be appropriate for everyone. This is especially true of people with a history of seizures or an eating disorder like anorexia or bulimia.

Like all antidepressants, Wellbutrin, Prozac, and Effexor carry a black box warning. This states their potential for increased risk of suicidal thoughts and actions in children, teens, and young adults during the early stages of treatment.

If you are having suicidal thoughts, contact the National Suicide Prevention Lifeline at 1-800-273-8255 for support and assistance from a trained counselor. If you or a loved one are in immediate danger, call 911. 

For more mental health resources, see our National Helpline Database.

Antidepressants and Weight Gain

Weight gain while taking an antidepressant is complicated. There is some research investigating the interaction of brain chemicals, antidepressants, and hormones that might result in weight gain, but more study is needed.

One study found that about 65% of people taking antidepressants experienced weight gain. Another noted that weight gain can be a "significant cause" of discontinuing treatment in the first two months.

However, not all antidepressant medications have this side effect. Research shows weight gain is mostly linked to a few antidepressants:

  • Paxil (paroxetine) and Celexa (citalopram): Selective serotonin reuptake inhibitors (SSRIs) 
  • Elavil (amitriptyline): A tricyclic antidepressant 
  • Remeron (mirtazapine): An atypical antidepressant 
  • Nardil (phenelzine): A monoamine oxidase inhibitor (MAOI)

Weight gain associated with other antidepressants, if it does occur, is usually short-lived. In addition, individual factors seem to play a role. In other words, it's hard to predict who will gain weight on certain antidepressants because so many variables are at play.

Antidepressants That Don't Cause Weight Loss or Gain

Some antidepressants appear to be weight-neutral (they are not associated with weight gain or weight loss). These include Trintellix (vortioxetine), Manerix (moclobemide), Pristiq (desvenlafaxine), and trazodone.

Why Antidepressants Affect Weight

One reason antidepressants can cause changes in weight is that some of these medicines impact appetite pathways. Antidepressants that cause weight loss may do so by causing your appetite to decrease. Those that cause weight gain may stimulate the appetite instead.

Depression itself can also affect your activity levels, food choices, and sleep habits—all of which affect weight. So, as the medication begins to reduce feelings of depression, these behaviors can also change. As these behaviors change, you may find that you gain or lose weight.

Your family history may even impact whether your weight will change while taking an antidepressant. For instance, one study found that a family history of obesity helps predict weight gain when taking this type of drug.

Choosing an Antidepressant

Treating your depression is paramount to your mental health and well-being. Your physical appearance and health are also important. Have a candid discussion with your doctor about depression treatment, as there are a lot of options. In general, it is best to avoid making a decision based on weight-related side effects, as these can be unpredictable and also temporary.

Often, it is difficult to know which antidepressant will work best for you. It may take some trial and error to find a medication that is effective and also does not cause unmanageable side effects. Always discuss your treatment with your doctor (never stop taking your antidepressant without your doctor's go-ahead).

Preventing Weight Loss or Gain While Taking Antidepressants

If you have concerns about weight-related side effects, talk to your doctor about diet and exercise changes you can make as well. These can also improve your emotional and mental health. Often, a combination of medication and a healthy lifestyle is the best treatment plan for depression.

Exercise

Whether you are hoping to lose weight, mitigate weight-related side effects from your antidepressant, maintain your weight, or gain weight, exercise can help. And you can start small. Walking, stretching, and moderate-intensity resistance training can all be helpful.

What's most important is consistency. The Physical Activity Guidelines for Americans suggest at least 150 minutes to 300 minutes a week of moderate-intensity exercise for health benefits. That's 30 to 60 minutes, five days a week, of any exercise you enjoy, from bicycling to swimming to tennis to yoga.

Diet

Eating a diet rich in whole foods, including fruits, vegetables, whole grains, lean proteins, and healthy fats, can help with weight management. But it may also help improve your mood since there is a connection between diet and depression.

Try making small swaps and changes every few days or every week. If you typically drink fruit juice, for example, switch to water and whole fruits; you'll get less sugar and more satiating fiber this way. Another way to get more fiber is by choosing whole grains (such as whole-wheat bread) over refined grains.

Antidepressants As Weight Loss Aids

If you do not have depression, antidepressants are not recommended for weight loss. Studies have found that taking these medications for that purpose has negligible results. There's no proof that it helps any more with losing weight than diet and exercise alone.

Can Prozac make you lose weight? Yes. But losing weight by eating nutritious foods and getting regular physical activity is recommended over trying a "Prozac weight loss diet."

If weight loss is your main concern, talk to your healthcare provider about the best way to work toward a weight-loss goal. There are some prescription medications approved for the treatment of obesity, including Contrave.

Contrave is a combination of bupropion (the active ingredient in the antidepressant Wellbutrin) and naltrexone (which is also used to treat some substance use disorders). Research has shown it to be fairly effective, well-tolerated, and safe. As with many medications used for weight loss, it's typically used in combination with a reduced-calorie diet and an exercise program.

A Word From Verywell

Treating depression takes patience and resilience as you find the right plan, but it can be done. While antidepressants can cause weight loss or gain, you can take steps to optimize both your physical and mental health. Your efforts in one area will support the other.

Frequently Asked Questions

  • Which antidepressants give you energy and weight loss?

    Wellbutrin (buproprion) is a stimulating antidepressant and it is also sometimes associated with weight loss. However, there is no guarantee that taking Wellbutrin will give you energy or cause weight loss.

    One research review found that medications including Provigil (modafinil), flupenthixol, and Strattera (atomoxetine) helped improve symptoms of fatigue and low energy in people with depression. However, these are not antidepressant drugs. 

  • Why am I losing weight on antidepressants?

    Some antidepressants may be associated with weight loss, perhaps due to an effect on appetite or improved energy. But scientists are still working to understand why some people lose weight while taking antidepressants.

  • What is the best antidepressant if you are trying to lose weight?

    It is more important for your antidepressant to treat symptoms of depression than to promote weight loss. If you are trying to lose weight and you also need to take an antidepressant, talk to your healthcare provider about the best antidepressant for you. You may be able to avoid antidepressants associated with weight gain in favor of one associated with weight loss, if it is appropriate for your specific needs.

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