The short answer is no, reducing the mg you take will not cause weight loss. The only things that can do that is diet and exercise. When I took Effexor, it was weight neutral for me but then during that time I remained depressed most of the time and stopped eating much. Now, after many different psychotrophic drugs, I weight about 40 pounds more than I should. I am currently changing my eating habits and "thinking" about exercise... LOL