Can cymbalta (duloxetine) cause weight loss?

Weight gain: All antidepressants can cause weight gain as part of their side-effect profile. In the case of Cymbalta (duloxetine) it's uncommon.

Sometimes: Cymbalta (duloxetine) is not a weight loss agent. In short term clinical trials lasting up to 9 weeks, patients on average lost about 1 pound on Cymbalta (duloxetine) and a little more than 1% lost greater than or equal to 7% of their body weight. On the other hand about 1/2 % gained greater than or equal to 7% of their body weight. Longer term data tended to favor a very modest weight gain, again on average.