Does Zoloft cause weight gain?

Zoloft (sertraline) is a prescription medication that belongs to the selective serotonin reuptake inhibitor (SSRI) class of antidepressants. Zoloft is often prescribed as part of a treatment plan, which may include other methods such as cognitive behavioral therapy, to treat major depressive disorder (depression) or other mental health conditions, including:

• Obsessive-compulsive disorder (OCD)
• Panic disorder (PD)
• Post-traumatic stress disorder (PTSD)
• Social anxiety disorder (SAD)
• Premenstrual dysphoric disorder (PMDD)

Zoloft is a popular antidepressant medication. As of 2020, more than 38 million prescriptions have been written for this medication. Many patients want to know if Zoloft will cause weight gain. In fact, one of the most common reasons why people stop taking SSRIs is because of weight gain. Zoloft may cause weight gain with long-term use. It may also cause a slight weight loss in children. Continue reading to learn more about Zoloft and its effect on body weight.

Does Zoloft cause weight gain?

Because everyone is different in their symptoms of depression or anxiety, as well as side effects and response to medication, weight changes due to Zoloft will vary by individual. One person may gain weight while another may lose. Some people eat more when they are depressed, and when they start taking Zoloft and feeling better, they may return to a normal diet and lose weight. On the other hand, some people experience appetite loss when depressed and eat less. Then, when taking Zoloft and starting to feel better, they may start to eat more and gain weight. 

While it is difficult to know how each person will respond to Zoloft in terms of weight gain, we can look at the results of some clinical studies. 

• A 2016 study looked at weight gain in adults after two years of antidepressant use. In this study, people who took sertraline gained an average of 5.9 pounds after two years.
• A review of many studies published in 2017 noted that a small weight loss may occur with short-term use of SSRIs, including Zoloft—in an 8-week study, individuals who took Zoloft lost an average of 1.58 pounds. However, short-term use of SSRIs is very unusual, because most people take SSRIs for at least 6 months—or much longer. The review noted a 2000 study, which looked at people who took an SSRI for up to 32 weeks and found sertraline to cause a weight gain of 1% (this would equate to a 1.8-pound weight gain for someone who weighs 180 pounds). And 4.2% of individuals who took Zoloft gained more than 7% of body weight (which would equate to at least 12.6 extra pounds for someone who weighs 180 pounds). 

In terms of children, Zoloft may affect growth hormones, which may slow growth and cause weight loss. Children who take Zoloft will have their height and weight monitored regularly.

Why does Zoloft cause weight gain?

Weight gain due to Zoloft (or any SSRI antidepressant) is thought to possibly be due to several factors, including: 

• By affecting serotonin receptor activity, which may regulate appetite and weight
• By increasing appetite, especially carbohydrate cravings
• By improving symptoms of depression, and helping appetite return to normal in those who had appetite loss

Other SSRIs and weight gain

SSRI weight gain can occur with other SSRIs besides Zoloft. A 2018 study in the British Medical Journal (BMJ) looked at the long-term use of antidepressants and weight gain. The study found that those who took an antidepressant had an increased risk of at least a 5% increase in weight, as opposed to individuals who did not take an antidepressant. Weight gain increased in the second and third years of treatment. The study researchers concluded that antidepressant use increased the risk of weight gain over at least 5 years. 

A 4-year study published in 2017 concluded that SSRI use was associated with weight gain—in combination with certain lifestyle factors including a Western diet, lack of activity, and smoking.  

The 2017 review of studies (mentioned in the section above) noted that some individuals gain what is considered to be an “extreme” amount of weight, which is more than 7% of body weight. Paxil (paroxetine) caused the most weight gain. In the study, 25.5% of people who took Paxil, 6.8% of people who took Prozac (fluoxetine), and 4.2% of people who took Zoloft (sertraline) gained more than 7% of body weight.  

Another study also concludes that Paxil (paroxetine) may be most likely to cause greater weight gain than other SSRIs during long-term treatment. Interestingly —bupropion, which is not an SSRI, also known by its brand name, Wellbutrin, is an antidepressant that may cause weight loss—and is one ingredient in the weight-loss drug Contrave. 

One study examined adults using antidepressants for 6 to 36 months and found that 55% of people gained weight. Of these, almost 41% gained 7% or more of their weight compared to baseline. The study found Celexa (citalopram), Lexapro (escitalopram), Paxil (paroxetine), and Zoloft (sertraline) to be associated with significant weight gain—but not Prozac (fluoxetine). The study also found some serotonin-norepinephrine reuptake inhibitors (SNRIs) to cause weight gain, including Cymbalta (duloxetine) and Effexor (venlafaxine).  

Although SSRIs and SNRIs may cause weight gain, other types of antidepressants may cause weight gain as well. For example, tricyclic antidepressants such as Elavil (amitriptyline) or Pamelor (nortriptyline) are well-known for causing weight gain. And Remeron (mirtazapine), which is classified as a tetracyclic antidepressant, is known for causing significant increases in body weight and body fat. 

How to avoid Zoloft weight gain 

Not everyone will gain weight when taking Zoloft or an SSRI, especially if you are aware and proactive. Here are some tips to help avoid weight gain while taking Zoloft—or any antidepressant: 

• First, do not stop taking Zoloft suddenly, even if you start to gain weight. Stopping an SSRI suddenly can cause withdrawal symptoms—as well as worsen depression or anxiety. If you have any concerns about your medication, consult your doctor first. You and your healthcare professional will need to consider all options regarding which medication is best and the possibility of weight gain. For example, a weight gain of 3 pounds over several years can be considered insignificant when compared to living with symptoms of depression. However, a larger weight gain caused by an antidepressant could lead to other health problems like high blood pressure, which could require either lifestyle changes or a change to a different drug.
• If you have gained weight, ask your healthcare professional if there could be another cause. The SSRI may not necessarily be the culprit of weight gain. Another medical condition could be the cause.
• Talk to your healthcare professional, or consult a registered dietician, about lifestyle changes, such as incorporating a healthy diet of nutritious foods and an exercise plan that will fit into your life. According to the Centers for Disease Control and Prevention (CDC), adults should get at least 150 minutes of moderate-intensity physical activity every week, plus two strength-training sessions. This can be done, for example, by walking for 30 minutes, 5 days per week, and adding in two strength-training workouts. You can walk outside, or even around a mall—or check YouTube for thousands of free exercise videos, including walking videos. In addition to helping avoid weight gain, this benefits overall health, too.
• Keep track of your weight while taking Zoloft. This way, you can see if there is a pattern of weight gain, and make changes if necessary.
• If weight gain becomes a problem, or you do not want to take a medication that may make you gain weight, ask your healthcare provider for medical advice about trying a different medication—such as bupropion—with a lower risk of weight gain. 

Ask your healthcare professional for other ideas that are personalized to your individual needs. Working together with your healthcare team, you will be able to find the treatment that works best for your depression or anxiety—while also minimizing weight gain.