I began taking Tramadol for pain in my knees after skiing. I hate going to doctors so I acquired some from one of the many available legal sources. It worked quite well for the pain and doses around 200mg had similar affects to Hydrocodone without any stomach upset.
While taking it, I noticed an unreported affect; that being a significantly reduced appetite. This occurs at the normal 100mg dose (for my weight). In fact, over a period of three weeks I lost 10lbs. I simply just didn't eat as much. I am continuing to use it while attempting to drop another 30lbs.
On the down side, difficulty urinating, constipation and slight withdrawals while waiting about three days for a refill have been noticed, however, they are not sever and are manageable.