Does Effexor Cause Weight Gain? What Studies and People Report
In the FDA trials Effexor XR more often lowered appetite, but over months some people report gaining weight.
By withClaro Editorial · 2026-11-02 · 4 min read
Clinical section reviewed by Dr. Jason Tan , Consultant Psychiatrist, on October 27, 2026.
Key takeaways In the FDA trials, loss of appetite was more common on Effexor XR than on placebo. A 2024 study of 183,118 people found about 0.17 kg (under half a pound) more gain on venlafaxine than on sertraline after six months, a small average difference. Of 173 people on Reddit who said whether their weight changed, 113 gained, 29 lost, 24 noticed no change and 7 went both ways. Of 48 who gave a reason for gaining, 21 named a bigger appetite, and 12 said they were eating the same or less. On this page
What 173 people on Reddit said about their weight on Effexor How does Effexor compare with other antidepressants for weight? Why can Effexor cause weight gain? Effexor (venlafaxine) can cause weight gain for some people, though in the short trials it more often lowered appetite: loss of appetite affected about 10% of people on Effexor XR against 3% on placebo, across its trials in depression and anxiety disorders. Those are two phases rather than a contradiction: a smaller appetite in the first weeks, and in some people a gain that builds over months.
What 173 people on Reddit said about their weight on Effexor
We read 100 recent threads about weight on r/Effexor and r/antidepressants, comments included, and 224 people described their own experience on Effexor. Unlike a study, nobody weighed them: these are their own accounts, and people with a change to report are more likely to post, so treat these numbers as what change looks like when it happens, not how often. Of the 224, 173 said whether their weight changed, and most of them gained: 113. Of the 48 who gave a reason for gaining, 21 named a bigger appetite or cravings, but 12 said they were eating the same or less, so gain isn't always about eating more, and that is worth telling your prescriber.
What people reported Of 173 people Gained weight 113 Lost weight 29 No change 24 Weight went both ways over time 7
One person on r/Effexor wrote:
Effexor has greatly increased my appetite while I’ve been on it
For another, nothing much changed:
My weight has remained fairly normal no major losses or gains in weight.
How does Effexor compare with other antidepressants for weight?
Close to the middle of eight common antidepressants, and the differences between them are small. A 2024 US study of 183,118 people's health records compared weight six months after starting each one, measured against sertraline. People who started venlafaxine gained about 0.17 kg (under half a pound) more than those on sertraline; bupropion was linked to the least gain, 0.22 kg less than sertraline. The authors call these small differences in average weight. The study also looked at the chance of gaining 5% or more of body weight: it was 10% to 15% higher for escitalopram, paroxetine and duloxetine and 15% lower for bupropion, and venlafaxine was not among the drugs that stood out. Only 28% to 41% of people were still taking their medicine at six months, which limits the study.
Why can Effexor cause weight gain? Medically reviewed by Dr. Jason Tan on October 27, 2026, this section only.
Why it builds isn't fully known for venlafaxine. The label lists both weight gain and weight loss among reactions seen in its trials, but gives a rate only for decreased appetite, 9.8% against 2.6% on placebo. Gain, when it comes, tends to build later, and the likely contributors are appetite, cravings, activity and sleep. The clinical view:
Weight can change on an antidepressant, and noticing a change early gives you the most options.
In the first weeks, some people lose a little weight because of nausea or a smaller appetite. Gain, when it happens, usually builds over months, though with a few medications it can start within weeks. It varies a lot between people on the same medication.
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. ## What should you tell your prescriber about weight changes?
Beyond a steady rise or loss, it helps to tell them:
When you started Effexor, your dose and any dose changes. When you first noticed a change, and whether it's still going. Changes in appetite, energy or sleep since starting. Whether your clothes fit differently. Any history of an eating disorder; if eating or weight is becoming hard to cope with, find support near you. If you're thinking of stopping, plan it with your prescriber. More in Effexor withdrawal .
Download on the App Store Appetite and energy on Effexor can shift over months. The withClaro app lets you log appetite, energy, sleep and mood each day, linked to your dose, and turns it into a report for your prescriber.
Frequently asked questions How much weight do people gain on Effexor? Of 67 people on Reddit who gained and gave a number, the median was about 30 pounds, and half gained between 20 and 44. These are people who chose to post about a change, so it is not what to expect for everyone.
Is Effexor worse than Wellbutrin for weight? In the 2024 study, each drug was compared with sertraline, not with each other: venlafaxine came out slightly higher and bupropion slightly lower. The gap is small on average, so raise weight when choosing a medication.
Will I lose the weight after stopping Effexor? There is little data on weight after stopping: on Reddit, 11 people who had gained and stopped said what happened, 9 that the weight came off and 2 that it did not, too few to say how often. Weight is a reason to talk about the dose or another medicine; stopping on your own can bring withdrawal and a return of symptoms.
Related articles
More about Effexor Same topic, other medications
Sources EFFEXOR XR (venlafaxine) prescribing information, US Food and Drug Administration via DailyMed, revised August 2023 Petimar J, et al. Medication-induced weight change across common antidepressant treatments: a target trial emulation study. Annals of Internal Medicine, 2024 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).