Does Zoloft cause weight gain?
Direct Answer
Zoloft (sertraline) can cause weight changes in both directions. In short-term trials, some patients actually lose weight due to nausea and appetite suppression. However, long-term use (6+ months) is associated with modest weight gain in some patients — typically 5-10 pounds, though individual variation is wide. The mechanism is not fully understood but may involve serotonin's effects on appetite regulation and metabolism. Among SSRIs, sertraline is considered weight-neutral to mildly weight-promoting — paroxetine (Paxil) tends to cause more weight gain, while fluoxetine (Prozac) is the most weight-neutral.
Based on published clinical trial data and FDA prescribing information. This is not medical advice — always consult your healthcare provider.
Supporting Evidence
Side Effects
Serious (rare)
- Suicidal ideation (especially in under-25, first weeks) — Black Box
- Serotonin syndrome (with other serotonergic drugs)
- Bleeding risk (especially GI with NSAIDs)
Clinical Trials
Response rate 40-50%; remission rate 30-35%; placebo response ~30%
Funding transparency: Pfizer originally funded major trials. Publication bias: negative studies often unpublished. FDA analysis showed average effect size modest (NNT ~10, but much less in mild-moderate depression). See full funding details
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