Does Zoloft Cause Weight Gain?

By Evelyn Duvivier, MD
Medically reviewed checkmarkMedically reviewed
March 28, 2022

More Americans are talking to their doctors about mental health and getting help. From 2009-2018, the number of U.S. adults taking a prescription antidepressant increased from 10.6% to 13.8%.

While antidepressants can alleviate symptoms of depression and anxiety, they may also cause unwanted side effects. In some patients, this can include weight gain.

Zoloft is a popular antidepressant prescribed for depression.

If you’ve been prescribed this medication or its generic version, sertraline, you may have experienced an improvement in your mood, sleep, and energy levels.

Your appetite might also have increased.

Along with these changes, you may begin to notice you have put on a little weight.

This is unfortunately a possible side effect of many antidepressant medications.

Knowing what to expect can help you manage your symptoms and create healthy lifestyle changes while you are on Zoloft.

In this article, I’ll explain more about why you may gain weight while taking Zoloft or another antidepressant.

I’ll also talk about the other side effects of this medication.

I’ll provide some ways to manage your weight while taking Zoloft, list a few precautions, and tell you when to talk to your doctor.

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Zoloft Weight Gain

If you have been dealing with depression, anxiety, panic attacks, obsessive-compulsive disorder (OCD), post-traumatic stress disorder (PTSD), or social anxiety disorder (social phobia), your doctor may prescribe you Zoloft to treat your symptoms.

Zoloft is a brand name for sertraline hydrochloride. It is a type of antidepressant called a selective serotonin reuptake inhibitor, or SSRI.

SSRIs work by boosting the serotonin levels in your brain.

Serotonin is a neurotransmitter, a molecule used by your nervous system to carry messages between neurons within the brain and between the brain and the rest of the body’s nervous system.

Under normal circumstances, serotonin conveys a message to a cell receptor, and then excess serotonin molecules are reabsorbed back into the body to be recycled.

When someone takes an SSRI, the medication inhibits the “reuptake” process, increasing the brain’s level of serotonin and giving it more opportunities to communicate. 

Serotonin helps humans think, learn, and remember.

It also helps stabilize mood, balance emotions, regulate appetite, and improve sleep, among other things. Healthcare clinicians aren’t sure whether low levels of serotonin cause major depression and other mental illnesses or vice versa.

We do know that using medications and other treatments to boost and rebalance serotonin levels can positively impact a patient’s mental well-being and quality of life.

Zoloft was first approved for medical use in 1991 by the U.S. Food and Drug Administration (FDA).

It is only available by prescription.

Sertraline is taken orally, in pill or concentrated liquid forms, once a day in the morning or evening.

If it is being used to treat premenstrual dysphoric disorder (PDD), the dose may be prescribed once a day, either every day of the month or on certain days of the month.

Why antidepressants cause weight gain

Serotonin not only regulates your mood and anxiety, but is also involved in control of your appetite.

Consequently, when taking antidepressants, you may develop increased cravings for carbohydrate-rich foods, such as bread, pasta, and desserts.

This can cause weight gain if not monitored and balanced with an active lifestyle.

Experts are not certain what specifically causes weight gain when taking SSRIs.

One hypothesis is that the drugs trigger changes in your metabolism due to the fluctuation in serotonin.

It’s also possible that you may have been eating less when you were depressed and as you start to feel better, your appetite may return.  

Not everyone gains weight while taking an SSRI.

The medications can affect patients in different ways.

Some people put on weight while taking their medication; some lose their appetite or lose weight instead. 

Other common SSRIs that cause weight gain

Most SSRIs have been associated with weight loss when used in the short term.

However, long-term use can result in weight gain.

Other common SSRIs that can cause weight gain include:

While weight gain has been linked to all of these antidepressants, studies have found that some drugs are more susceptible than others.

There are more cases of weight gain with paroxetine than with sertraline or fluoxetine.

Zoloft Side Effects 

Typically, mild side effects of Zoloft will taper off after the first week as your body gets used to the medication. Some common side effects include:

More serious side effects require medical attention.

These include:

  • Suicidal thoughts or actions
  • Seizures or convulsions
  • Symptoms of serotonin syndrome
  • Difficulty breathing
  • Fast, irregular heartbeat
  • Skin rash or hives
  • Swelling of the face, lips, tongue, or throat
  • Black or bloody stools
  • Shaking
  • Unusual weight loss
  • Vision changes or blurred vision
  • Vomiting 

Managing Your Weight While on SSRIs

You can manage your weight while on SSRIs by being conscious of your daily diet, increasing physical activity, trying a limited daily window for eating, and getting adequate sleep. 

Watching what you eat

SSRIs can increase appetite.

You may feel strong cravings for foods rich in carbohydrates.

Be mindful of what you are eating when on Zoloft. Simply paying attention to what you’re eating—on purpose, and without judging yourself—can often lead people to maintain a healthy weight.

This is called “mindful eating.” Though it’s based on practices from Zen Buddhism, you don’t have to meditate to eat mindfully.

Try eating while sitting down, and have meals without your phone or the television screen in front of you.

These simple acts will increase how mindful you are of what you’re eating, and why.

Increase activity 

After taking Zoloft for a few weeks, you may notice a greater interest in activities.

Suddenly, you may find yourself feeling inspired to go on a run or join a fitness class.

Use this to your advantage.

Try to include 30 minutes of physical activity about five times a week.

Intermittent fasting 

Intermittent fasting is a strategy where people reduce the number of hours each day during which they eat, setting a “window” for taking in their daily calories.

Some people fast for 12 hours, eating all their meals in the other 12 hours.

Others fast for 16 or even 20 hours.

Other types of intermittent fasting alternate lower-calorie days with regular eating—one popular form is “5:2,” in which people eat significantly less for two days per week.

Intermittent fasting usually results in fewer calories consumed overall, which can lead to weight loss.

Studies have also found that restricting the eating “window” can increase insulin sensitivity in certain patients, which may help with weight loss.

Talk to your doctor before starting any diet regimen to make sure it’s safe for you.

Quality sleep

Many studies have shown a connection between sleep and obesity.

In one study, people who slept five hours per night were 15% more likely to be obese than those who slept seven or more hours per night.

You can improve your sleep by creating a bedtime routine that primes your body for sleep.

Try to go to bed at the same time each day.

Shut off distractions, such as screens, at least an hour before bed.

And give yourself enough time to get to sleep. 

Precautions and Warnings 

Before taking Zoloft, tell your doctor if you are allergic to it or have any other known allergies.

Tell your doctor about any other medications you are taking, including over-the-counter medications and supplements, to avoid negative drug interactions.

There are several SSRIs that work effectively in treating depression.

Tell your doctor about your medical history and symptoms so they can prescribe the best one for you.

What to avoid when taking Zoloft

Avoid drinking alcohol when taking sertraline.

When you drink alcohol, your serotonin levels are temporarily spiked.

Mixing this with Zoloft may bring a temporary high, but can cause a worsening of your symptoms of depression and anxiety in the long term.

In some people, it can even cause a higher risk of suicidal behavior.

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When to See a Doctor 

Do not stop taking Zoloft without medical supervision.

Talk with your doctor if you wish to lower your dose or stop the drug.

They will be able to determine the best treatment for you. 

If you are experiencing worsening symptoms while taking Zoloft, talk to your healthcare provider.

Seek medical attention immediately for any of the following serious side effects:

  • Suicidal thoughts or tendencies
  • Seizures
  • Vision changes including blurred vision, eye pain, redness, or swelling
  • Manic episodes: unusual risk-taking behavior, rapid speech, extreme happiness, being irritable, and increased energy
  • Hallucinations, memory loss, confusion, or headaches
  • Shivering
  • Sweating
  • Vomiting
  • Diarrhea
  • Accelerated heart rate 

How K Health Can Help

Think you might need a prescription for Zoloft (Sertraline)?

K Health has clinicians standing by 24/7 to evaluate your symptoms and determine if Zoloft is right for you.

Get started with our free assessment, which will tell you in minutes if treatment could be a good fit. If yes, we’ll connect you right to a clinician who can prescribe medication and have it shipped right to your door.

K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.

Evelyn Duvivier, MD

Evelyn Duvivier MD MPH is a Yale Medical School graduate who is board certified in emergency medicine and internal medicine and has worked for over a decade in emergency rooms as well as pro bono for uninsured patients in an internal medicine clinic.

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