Strength Implant

The Hypertrophy Accelerator Strength Implant is an implant perk

Requirements
The implant can't be picked when one levels up. It can be bought from Doctor Usanagi in the New Vegas medical clinic for 4000 caps, designed to enhance the adrenaline output of the body and then muscle mass of the person it's installed in by acting as an automatic version of steroids, forcing the body to make a large amount of muscle mass.

Behind the scenes
Hypertrophy is the condition where the volume of tissue increases as a result of a growth in the size of the component cells. In this case, the growth of musculature by enlarging the muscle cells is referred to as 'muscular hypertrophy'.