Mutant Growth Hormone (also known as MGH) is a naturally occurring hormone produced within mutants and genetically altered superhumans. This hormone is used to either temporarily boost the powers of mutants, or grant mutant powers to non-mutants.
Ajax created a serum containing the Mutant Growth Hormone that is meant to activate any mutant genes that lie dormant within a person's DNA. Adrenaline acts as a catalyst for the serum, so in order for the serum to work, the individual has to be subjected to extreme levels of stress. If the serum works, the individual's mutant genes will manifest in a spectacular fashion. If not, then the individual will have to continue enduring high levels of stress until they either mutate, or die. People injected with MGH serum don’t always obtain the same powers as one another, because the treatment effects people differently, granting varying powers to different people. After successfully manifesting their mutant powers, the non-mutants become Mutates.
Alkali-Transigen invented their own MGH serum, but this version involves increasing the powers of mutants for a short period of time. However, due to it's potency, it is too dangerous to take large quantities of the MGH serum in a single dose, which is why it's safer for mutants to receive it in smaller doses. Side effects of taking excessive amounts of the MGH serum include increased aggression, and the potential death of the user. Once the effects of the serum wear off, the user will notice their powers aren't as potent as they were when they took it, as shown when Wolverine and Laura noticed that the former's Regenerative Healing Factor stopped working efficiently.
- Ajax - Enhanced Reflexes, Pain Supression, Superhuman Durability, Superhuman Strength
- Angel Dust - Adrenaline Activation
- Deadpool - Regenerative Healing Factor, Superhuman Agility, Superhuman Durability, Superhuman Reflexes, Superhuman Speed, Superhuman Strength
- Marrow - Bone Spike Protrusion
- In the comics, Hank McCoy designed the Mutant Growth Hormone, but in the films, Ajax and Alkali-Transigen designed their own versions instead.
- In the comics, the Mutant Growth Hormone has two effects, both of which are temporary: boosts the powers of mutants or grants mutant powers to non-mutants. But in the films, the effects are separate, having been invented by different people.
- Although Ajax's MGH serum grants powers to non-mutants, the effects are permanent and require high-stress levels to activate, whilst in the comics the Mutant Growth Hormone's effects are temporary and the powers spontaneously activate after consumption/injection.