USN Creatine-X4 IS The new generation creatine energy stack formulated to build lean muscle without the assistance of high-GI carbs & loading. Creatine X4 provides a revolutionary form of creatine which does not rely on insulin for its uptake. Creatine Ethyl Ester HCl is a fat soluble form of creatine. It stores as a phosphate in the muscle cells for ATP to regenerate.