injectable B12
equipoise
Injectable B12 doesn't do shit for appetite.
The drug pizotifen works really well, but it makes you sleep much more than you normally do.
I find the best thing to do is cut out all the junk food, processed food, and eating at restaurants, and start with just protein and veg. You will be very hungry, and you can start adding in carbs and/or fats to build up your appetite.
I would also stay away from protein shakes, they seem to decrease appetite when compared to home cooked beef, chicken, fish, eggs, etc.