looking for a good supplement to take for muscle building and weight loss?

the only supplement i have stuck by is whey protein. i used it this past summer and all i did was gain weight. i was convinced it was muscle, but it was obvious the fat wasn’t going anywhere. i am really looking to lose quite a good bit of fat, but continue to build the muscle. is there any supplement out there that is not going to give me side effects, help me with my goal, and not be soo expensive? and something that won’t effect me when taking multivitamins and/or omega-3s?
thanks!!

I use a chemical free whey protein minus the fillers and additives. The company is http://www.buybulkwhey.com and they are a natural company. I prefer the chocolate myself with skim milk. You can get a 5lb tub for $26.99 good price

Fitness & Exercise Tips : Muscle Building Supplements