Does Zoloft Cause Weight Gain? What the Research Shows
Zoloft can lead to weight gain, but the average change is small and differs a lot from person to person. Here is what the studies show and what you can do about it.
By withClaro Editorial · 2026-10-23 · 7 min read
Medical review pending. Written by the Claro editorial team from the FDA label and published studies.
Key takeaways Zoloft can cause weight gain. In large studies the average change is small, and many people do not gain at all. Some people lose a little weight in the first weeks, because Zoloft can cut appetite and cause nausea. Gain, when it happens, usually builds slowly over months. One large study found the extra risk lasted for years. Noticing a steady rise early and raising it with your prescriber gives you the most options. On this page
Can Zoloft cause weight gain? Does Zoloft cause more weight gain than other antidepressants? When does weight gain on Zoloft start? What 216 people on r/zoloft said about their weight Why does Zoloft make you gain weight? Does the dose matter? How long does Zoloft weight gain last? Keeping track of changes on Zoloft Weight is one of the most common worries when starting Zoloft (sertraline). In large studies the average gain is modest, and the range between people is wide. Some lose a little weight at first, some stay the same, and some gain steadily over a year or more.
That spread is why people on r/zoloft argue about it so much.
Can Zoloft cause weight gain?
Yes, for some. How often depends on the study. In a 2015 study at a Turkish clinic, 55% of 362 people who had taken a newer antidepressant for 6 to 36 months had gained weight, and 41% had gained 7% of their body weight or more; that was one clinic, people on seven different drugs, looked at once. The NHS lists putting on weight among the common side effects of sertraline, while the FDA label does not list weight gain among common side effects in adults, only increased appetite among reports after it came on the market. A 2018 UK study of nearly 295,000 people over ten years found that people prescribed antidepressants were 21% more likely to gain at least 5% of their body weight; it looked at antidepressants as a group, and the authors note the link may not be fully causal.
Studies comparing sertraline with other antidepressants point the same way. In a 2016 study in a Washington State health system, people who started sertraline gained about 5.9 pounds more over two years than those on fluoxetine, though the true difference could be anywhere from under a pound to about 11 pounds. In the 2015 Turkish study, sertraline was one of seven antidepressants linked to significant gain after six months or more. There, gain of 7% or more was more likely in people with a lower body weight at the start, a family history of obesity and less education.
One person on r/zoloft wrote:
I have been taking it since the end of December and have gained about 5 kilograms (11 pounds).
Does Zoloft cause more weight gain than other antidepressants?
Among common antidepressants, Zoloft is on the lower side for weight gain. The largest comparison so far, published in 2024, followed 183,118 adults across eight US health systems and used sertraline as the reference.
Medication Weight change at 6 months, compared with sertraline Escitalopram (Lexapro) 0.41 kg (about 0.9 lb) more Paroxetine (Paxil) 0.37 kg more Duloxetine (Cymbalta) 0.34 kg more Venlafaxine (Effexor) 0.17 kg more Citalopram (Celexa) 0.12 kg more Fluoxetine (Prozac) about the same Bupropion (Wellbutrin) 0.22 kg less
The differences are small on average. Escitalopram, paroxetine and duloxetine were linked to a 10% to 15% higher risk of gaining at least 5% of body weight, and bupropion to a 15% lower risk. Fluoxetine looks the same as sertraline here at six months, while the 2016 study found more gain on sertraline over two years; the studies differ in length and in who was included, and the two-year figure is too uncertain to settle it. If weight matters a lot to you, raise it when choosing or switching antidepressants.
If weight is a deciding factor, how Wellbutrin and Zoloft compare covers the trade-offs.
When does weight gain on Zoloft start?
Gain tends to come later, over months rather than weeks. In the first weeks, weight more often goes the other way: in the clinical trials listed on the FDA label for Zoloft, 7% of adults reported decreased appetite, against 2% on placebo, and nausea affected 26%, against 12%.
A 2010 review of 116 studies put sertraline among the antidepressants with little or no effect on weight in the short term, and found that the effect became clearer with long-term use. Amitriptyline, mirtazapine and paroxetine carried a higher risk of gain. In the 2018 UK study, the extra risk was clearest from the second year of treatment.
So little change in the first month does not tell you much about month twelve; it makes more sense to look at weight over several months than week to week.
What 216 people on r/zoloft said about their weight
We read 100 recent threads about weight on r/zoloft, comments included, and 216 people said whether their own weight went up, down or stayed the same on Zoloft. These are people's own accounts, not measured weights, and people who gain are more likely to post than people whose weight didn't change, which is why their numbers run far higher than the averages in studies. About half, 105 of the 216, said they gained.
What people reported Of 216 people Gained weight 105 Lost weight 64 No change 30 Weight went both ways over time 17
Among the 59 people who gained and gave a number, the typical gain was about 30 pounds, and half said between 20 and 40. That is what gain looks like when it happens, not what to expect. Others saw no change; one person wrote:
I have not gained any weight on Zoloft.
In all, 122 people gained at some point, counting those whose weight went both ways. Of the 122, 29 pointed to a bigger appetite or cravings, and 12 said they ate the same as before.
Why does Zoloft make you gain weight? Clinical section: medical review pending
Researchers have not pinned down a direct cause for sertraline. For antidepressants in general, reviews point to serotonin and histamine pathways that help control appetite and fullness, though this is a working explanation that hasn't been confirmed. The histamine route fits drugs such as mirtazapine; Zoloft's label says sertraline has no significant affinity for histamine receptors. On top of that, weight change usually comes from several things at once, and they differ from person to person.
People describe the same mix in their own words. Some notice their appetite coming back as their mood lifts. Others notice cravings they did not have before, or less energy to move. Two people on r/zoloft wrote:
Since being on sertraline my appetite has increased but I’ve had a significant drop in energy, I find myself constantly lethargic.
I’ve noticed ever since I’ve been on it I have really strong cravings that are hard to control.
Weight is one of the things a prescriber weighs when choosing and adjusting a medication. The clinical view:
Weight can change on an antidepressant, and noticing a change early gives you the most options.
Several things feed into it: appetite returning as mood improves, cravings, less activity, poor sleep and the medication itself.
What you can do:
Mention a steady rise at your next appointment, while the change is still small. Raise weight loss that keeps going, or an appetite that has not come back after the first weeks. Your prescriber may adjust the dose or suggest a medication with a different profile. Stopping on your own to control weight can bring on withdrawal or a return of symptoms.
Does the dose matter?
People often ask whether 50 mg carries less risk than a higher dose. The large studies of antidepressants and weight compared medications, not doses, so they do not answer this for sertraline.
Some people on r/zoloft report gaining after a dose increase. That is worth tracking, but it is not the same as evidence. If you notice a change after a new dose, note the date and bring it to your next appointment.
How long does Zoloft weight gain last?
There are two questions here: how long the risk of gaining lasts while you take it, and whether weight comes off after stopping. On the first, the 2018 UK study found that in the second year of treatment one extra person in every 27 gained at least 5% of their body weight, and the extra risk stayed raised for at least six years of follow-up.
On the second, what happens to weight after stopping sertraline has not been studied well. On r/zoloft, of the 122 who gained, 17 said they lost some or all of it after stopping and 7 said they had not; most were still taking it. Stopping suddenly because of weight changes brings its own risks. Any change to treatment is a decision to make with your prescriber.
Plan any stop with your prescriber, since Zoloft withdrawal side effects are more likely after a sudden stop.
Keeping track of changes on Zoloft
A change is easier to act on when you can show when it started and what came with it. If keeping an eye on appetite or how clothes fit is hard for you, or thoughts about weight start to take over, especially if you have had an eating disorder, tell your prescriber; support is also listed on our find help page .
Before your appointment, note:
When you started Zoloft and when the dose last changed. When you first noticed a change, for example clothes fitting differently. What happened to your appetite, cravings, energy and sleep. Any other medications you take. Which side effect bothers you most. The withClaro app lets you log mood, energy, sleep and appetite each day. It links side effects to your dose and phase of treatment. The record becomes a report you can share with your doctor.
Download on the App Store Weight changing, appetite shifting, sleep or energy dipping? The withClaro app lets you log mood, energy, sleep and appetite each day, links side effects to your dose and phase of treatment and turns it into a report for your doctor.
Frequently asked questions Does being on Zoloft make it hard to lose weight? It can. Some people find their appetite and cravings rise, while energy drops. Note what changed and when, and discuss it with your prescriber.
How do I avoid gaining weight on Zoloft? There is no reliable way to prevent it in advance. Notice changes in appetite and energy, and if your clothes start fitting differently, raise it early, while the change is small. The options depend on you and your history, so it is a conversation with your prescriber.
Does Zoloft increase appetite? Some people say it does, often months into treatment, as mood lifts; in our count, 29 of the 122 who gained pointed to a bigger appetite or cravings. Early on, trials found the opposite more often. Log your appetite each day, so you can show your prescriber when it changed.
Will 50 mg of Zoloft cause weight gain? Not necessarily. Large studies have not compared weight change across sertraline doses. If you notice a change after starting or raising a dose, note the date and mention it at your next appointment.
Does Zoloft cause weight loss? In the first weeks, it can, since decreased appetite and nausea are common early side effects; 64 of 216 people on r/zoloft said they lost weight. In children, MedlinePlus notes it may reduce appetite and cause weight loss, and the label reports a slight loss in pediatric trials. If your appetite has not returned after the first weeks, tell your prescriber.
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Sources Petimar J, et al. Medication-induced weight change across common antidepressant treatments: a target trial emulation study. Annals of Internal Medicine, 2024 Gafoor R, Booth HP, Gulliford MC. Antidepressant utilisation and incidence of weight gain during 10 years' follow-up: population based cohort study. BMJ, 2018 Arterburn D, et al. Long-term weight change after initiating second-generation antidepressants. Journal of Clinical Medicine, 2016 Uguz F, et al. Weight gain and associated factors in patients using newer antidepressant drugs. General Hospital Psychiatry, 2015 Serretti A, Mandelli L. Antidepressants and body weight: a comprehensive review and meta-analysis. Journal of Clinical Psychiatry, 2010 Blumenthal SR, et al. An electronic health records study of long-term weight gain following antidepressant use. JAMA Psychiatry, 2014 ZOLOFT (sertraline) prescribing information, US Food and Drug Administration via DailyMed, revised August 2023 NHS. Side effects of sertraline MedlinePlus. Sertraline drug information, US National Library of Medicine r/zoloft: To anyone saying Zoloft can't cause weight gain r/zoloft: I can't even look in the mirror anymore (weight gain) r/zoloft: Has anyone gained weight on Zoloft? If so how did you manage it r/zoloft: Can someone tell me they successfully lost Sertraline weight gain? r/zoloft: Zoloft and weight gain? Gill H, et al. Antidepressant medications and weight change: a narrative review. Obesity, 2020 Claro articles are for self-monitoring and educational purposes only. They are not a medical device, therapist, or diagnostic tool, and do not replace care from your prescribing clinician. If you are in crisis, contact your care team, emergency services, the Samaritans (UK: 116 123), or the Crisis Text Line (US: text HOME to 741741).