If you’ve started taking an antidepressant and noticed the number on the scale creeping up, you’re not alone. Many people are surprised to learn that weight gain is a possible side effect of antidepressant use.
“Antidepressants are commonly prescribed for anxiety and depressive disorders,” said Divya Singh, MD, a psychiatrist with Banner Health. “Although not widely recognized, weight gain can happen in 25% to 30% of patients and some estimates suggest it may affect up to 55% to 65% of people.”
While these medicines can be life-changing, helping you feel more stable, hopeful and in control, they can also have frustrating effects on your body. The good news is that weight gain isn’t inevitable. You’ll likely be able to find a medication that helps your symptoms with little effect on your weight.
Read on to learn about why antidepressants may cause weight gain, which medications are more likely to do so and what you can do to take care of your body and mind.
Why antidepressants may cause weight gain
Understanding the connection between antidepressants and weight gain is complex.
“Weight gain isn’t influenced just by the medication itself but also by factors like changes in appetite, metabolism and activity levels that often come with depression and anxiety,” Dr. Singh said.
When you’re struggling with depression, your body and brain already experience shifts that can affect weight. You might eat more (or less), move less or crave high-calorie foods. Some people even develop binge eating patterns as a way to cope with emotional pain.
Antidepressants can add another layer to this. These medications affect brain chemicals called serotonin and dopamine, which play key roles in regulating mood and appetite. Over time, changes in these systems can lead to increased hunger or slower metabolism.
Not all antidepressants affect weight the same way
If you’ve heard that all antidepressants cause weight gain, that’s not entirely true. The likelihood depends on the type of medication and how long you’ve been taking it.
According to Dr. Singh, tricyclic antidepressants, monoamine oxidase inhibitors, selective serotonin reuptake inhibitors and a tetracyclic antidepressant called mirtazapine are linked to the most weight increases.
“A large review of 27 studies involving more than 450,000 people found that these medications, along with some SSRIs, had the strongest association with weight gain,” Dr. Singh said. “The researchers noted that people gained at least 5% of their body weight over time.”
On the other hand, you can also lose weight while taking antidepressants. Some antidepressants, like bupropion (Wellbutrin), may help you lose weight along with improving your mood.
Types of antidepressants and their weight-gain risk
Tricyclic antidepressants (TCAs)
Brand names include:
Pamelor, Aventyl, Elavil and Norpramin
TCAs are some of the earliest forms of antidepressants and aren’t commonly prescribed today because they can cause more side effects, including weight gain.
Monoamine oxidase inhibitors (MAOIs)
Brand names include: Nardil and Parnate
MAOIs are also an earlier form of antidepressants. They are often prescribed when other treatments have failed. MAOIs are more likely to cause weight gain.
Selective serotonin reuptake inhibitors (SSRIs)
Brand names include: Prozac, Zoloft, Lexapro, Celexa and Paxil
SSRIs may cause mild weight gain after months or years of use.
Serotonin-norepinephrine reuptake inhibitors (SNRIs)
Brand names include: Cymbalta and Effexor
These medications may increase the risk of weight gain.
Tetracyclic antidepressant (Mirtazapine)
Brand name: Remeron
Mirtazapine is commonly associated with increased appetite and weight gain.
Bupropion
Brand name: Wellbutrin
This medication is the most weight-friendly option. In some cases, it can lead to modest weight loss.
Vilazodone
Brand name: Viibryd
It is a newer antidepressant that may have a lower risk of weight gain.
Other factors that influence weight
Weight gain isn’t just about the medication. It’s also about your whole body and lifestyle.
Here are some common contributors:
- Genetics: Some people are naturally more prone to weight gain due to their DNA.
- Baseline BMI: Those who are already overweight may gain more easily while on medication.
- Diet and activity: A sedentary lifestyle and a high-calorie diet can amplify the effect of antidepressants.
- Underlying medical conditions: “Patients with diabetes or low thyroid function may have a higher risk of gaining weight on antidepressants,” Dr. Singh said.
These factors highlight why it’s so important to look at the whole picture, not just the prescription itself.
Tips to support a healthy weight
While not every cause of antidepressant-related weight gain can be controlled, your daily choices still matter. Even small, consistent changes can help.
Here are some steps to consider:
- Eat balanced meals: Focus on whole foods like fruits, vegetables, lean proteins and whole grains. Limit added sugars and processed snacks that can trigger cravings.
- Move regularly: Aim for at least 30 minutes of activity most days, such as walking, dancing or any movement you enjoy.
- Prioritize sleep: Lack of sleep affects hunger hormones and can increase cravings. Try to get 7-9 hours of quality rest each night.
- Track your weight gently: Check in with your weight and how your clothes fit but avoid obsessing over numbers.
- Manage stress: Mindfulness, yoga or therapy can help reduce stress and things like emotional eating.
When to talk to your provider
If you’re struggling to control your weight, talk to your health care provider. Never stop or change medications on your own.
Your provider may:
- Review your medication and look at other options
- Check for underlying conditions like thyroid issues
- Offer guidance on nutrition and exercise
- Discuss safe medication to help manage weight
“Some medications can be added to help with weight control,” Dr. Singh said. “Metformin, which is often used for diabetes, has been shown to help prevent and reduce antidepressant-related weight gain.”
Other options include GLP-1 receptor agonists, such as liraglutide and semaglutide, which have been effective in reducing weight gain in some patients. These medicines help with appetite and slow digestion, making it easier to maintain or lose weight.
However, medication alone isn’t the full answer. Combining it with healthy daily habits can make the biggest difference.
Takeaway
It’s easy to worry about weight and feel guilty, but your mental health is just as important as your physical health. Treating depression, anxiety and other mental health conditions can improve every part of your life.
Antidepressants may cause weight gain in some people but the reasons are complex and manageable. Work closely with your health care provider or a Banner Health specialist to discuss your treatment options.
