It does mask steroids in certain test, it just depends on the test given. Different tests pickup different illegal substances. The sad thing is, if you know your body well enough busting your butt,proper nutrion and supplementation will help you almost as much as illegal stuff will!!!
Google hcg and you'll get a boatload of stuff on it. It's the new weight loss rage. It's basically an enzyme created during pregnancy which spontaneously creates all kinds of stuff in the body, including weightloss. Men are using it in body building shows to cut fat and reveal more muscle. It also has other beneficial side effects, but no known long-term effects. Hence, I wouldn't touch it with a 10 foot pole. Who knows long-term what other problems it might cause.