Does Cymbalta Cause Weight Gain? What Studies and People Report
Cymbalta often lowers appetite at first, but over months some people gain 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, decreased appetite was more common on Cymbalta than on placebo. In a 2024 study of 183,118 people, duloxetine was among the three antidepressants with a 10% to 15% higher risk of gaining 5% of body weight, though average differences were under half a kilogram. In 76 r/cymbalta threads, about three times as many people said they gained weight as said they lost it. Of those who gained and later stopped, most said the weight came off afterwards. On this page
What 151 people on r/cymbalta said about their weight How does Cymbalta compare with other antidepressants for weight? Why can Cymbalta cause weight gain? What should you tell your prescriber about weight changes? Cymbalta (duloxetine) can cause weight gain for some people, though in the short term it more often lowers appetite. In the FDA trials for depression and anxiety, decreased appetite affected 6% of people on Cymbalta against 2% on placebo. Over months, the picture can change.
It also depends on why you take it. A 2011 pooled analysis of 16 duloxetine pain trials with 5,111 people, by authors from the maker, found that in the first months all groups lost weight against placebo. In trials longer than 3 months, people with diabetic nerve pain lost between about 0.3 and 1.7 kg, while people with fibromyalgia or back pain gained up to 1.1 kg.
What 151 people on r/cymbalta said about their weight
We read 76 recent threads about weight on r/cymbalta, comments included, and 187 people described their own experience. These are people's own accounts, nobody weighed them, and people with no change post less, so treat this as what change looks like when it happens, not how often. Of the 187, 151 said whether their weight changed: 96 said they gained and 30 that they lost.
What people reported Of 151 people Gained weight 96 Lost weight 30 No change 17 Lost at first, then gained, or the other way round 8
Counting the 96 who gained and the 8 whose weight went both ways, 104 gained at some point; 30 of them gave a reason: 15 said they were eating the same or less, 10 named a bigger appetite, and 5 gave other reasons. Of those who had since stopped Cymbalta, 17 said they lost the weight afterwards and 7 said they did not.
One person on r/cymbalta wrote:
I gained 40 pounds in 13 months
Another did not gain at all:
I never gained any significant amount on weight through it.
How does Cymbalta compare with other antidepressants for weight?
The differences between antidepressants are small, but duloxetine sits near the top for gain. A 2024 US study of 183,118 people compared weight six months after starting one of eight common antidepressants, each against sertraline. Duloxetine, escitalopram and paroxetine carried a 10% to 15% higher risk of gaining at least 5% of body weight; bupropion had a 15% lower risk.
Medicine Weight change vs sertraline at 6 months Escitalopram (Lexapro) about 0.41 kg more Paroxetine (Paxil) about 0.37 kg more Duloxetine (Cymbalta) about 0.34 kg more Venlafaxine (Effexor) about 0.17 kg more Citalopram (Celexa) about 0.12 kg more Fluoxetine (Prozac) about the same Bupropion (Wellbutrin) about 0.22 kg less
The authors call these differences small, under half a kilogram over six months, and people vary far more than that. The study used medical records, and adherence at six months was 28% for duloxetine, the lowest of the eight.
Why can Cymbalta cause weight gain? Medically reviewed by Dr. Jason Tan on October 27, 2026, this section only.
The exact reasons aren't known. Duloxetine is an SNRI, and early on it often brings nausea and a lower appetite, which can mean loss at first. On Reddit, 15 of the 30 who said why they gained said they were not eating more, a small group to go on. The clinical view on what feeds into weight change:
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. What fits next depends on you, your medicine and your history, which is a conversation with your prescriber. 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?
Bring the facts behind the change, so the conversation starts from dates rather than a guess. It helps to tell them:
When you started Cymbalta, your dose and any dose changes. What you take it for: depression, anxiety or pain. Whether your clothes fit differently. Any history of an eating disorder. If you're thinking of stopping, plan it with your prescriber. More in Cymbalta withdrawal .
Download on the App Store Appetite and energy on Cymbalta 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 Does Cymbalta make you lose weight at first? Some people lose a little early on, as nausea and lower appetite are common. If your appetite has not come back after the first weeks, raise it at your next appointment.
Will I lose the weight after stopping Cymbalta? Of people on r/cymbalta who gained and then stopped, 17 said the weight came off and 7 said it did not. Plan any stop with your prescriber, because stopping Cymbalta suddenly can bring withdrawal.
Is Cymbalta worse than Lexapro for weight? In the 2024 study, both were linked to a similar 10% to 15% higher risk of a bigger gain than sertraline. If weight matters to you, say so when you and your prescriber choose.
Does Cymbalta cause water retention? Swelling is not in the label's table of common side effects, but some people on r/cymbalta describe feeling puffy. Gradual puffiness in your legs is worth mentioning at your next appointment. Sudden swelling of the face, lips or throat, especially with trouble breathing, is an emergency: the label lists this kind of swelling, angioedema, among reports after approval. Call 911 in the US or your local emergency number.
Related articles
More about Cymbalta Same topic, other medications
Sources CYMBALTA (duloxetine) prescribing information, Eli Lilly and Company, revised August 2023 Gaynor P, et al. Weight change with long-term duloxetine use in chronic painful conditions: an analysis of 16 clinical studies. International Journal of Clinical Practice, 2011 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).