High Quality Content by WIKIPEDIA articles! Mutant Growth Hormone (MGH) is a fictional drug in the Marvel Universe. The drug is extracted from genetic material taken from genetic mutants or mutates, and it is usually presented in pill form. MGH grants temporary powers to whoever takes it, described as a "temporary genetic shift". Usually, when the source is unspecified, the effect is increased strength and aggression. If someone who already has superhuman powers takes MGH, those powers are enhanced.