I've tried the creatine Serum before and had some fair results with it, eventhough my body doesn't really like creatine. Most powdered creatines tend to bloat me a tad ( I know I've just painted a great image
Â ) Xenadrine and Creatine will not cancel eachother out as they each serve a different function. So you'll be OK. The best supplement I can recommend is glutamine. "Glutamine supplementation may promote nitrogen retention (a positive nitrogen balance) and prevent the loss of muscle protein (6). A decreased ratio of testosterone to cortisol is believed to be directly responsible for losses in muscle mass since cortisol promotes the synthesis of glutamine synthetase. By maintaining intracellular concentrations of glutamine within the skeletal muscles, the synthesis of glutamine synthetase mRNA may be inhibited and thus the loss of intracellular nitrogen through glutamine may be prevented. Furthermore, by enhancing plasma concentrations of glutamine, the demand for free glutamine by other tissues and cells (e.g. the small intestine and immune cells) is attenuated and thus the release of glutamine from muscle tissues is reduced (3). I use two scoops a day, one at lunch and one before bed. This has really helped me pack on some clean muscle (along with a good diet).