I had some weird head zips and felt tired for a couple of weeks, but it resolved. I did gain weight, but have managed not to gain more. It has worked for me, in combination with Tramadol, to keep my pain levels at 4-5 when life is good. It's better than being in agony everyday. I have other meds and supplements that I take, but these are the biggies.
Like all antidepressants its does take a while, up to six weeks, to get the full benefit. It can drop your blood pressure so if you typically have low blood pressure as I do, it's good to pay attention to it. When I start getting woozy, I know I need to lay down on the floor. Looks silly sometimes, but I stopped being embarrassed about most things long ago!
Hope it works for you.