Genetic Stabilizer

There are any number of people in the world with the potential to be an Enhanced. It's inherent in one's DNA, and it activates when the right cocktail of chemicals hits, usually because of extreme stress or other such factors. A lot of people will devote their lives to triggering this, or altering their DNA so they're capable of it in the first place, or developing technology so that they can jump the line, so to speak. There are whole organizations devoted to making it so that everyone (or at least all the people they like) has powers.
  In all that, it is sometimes a surprise to find that there is a population that does not want powers at all, and will devote resources to ensuring that this is never an issue. Sometimes it's cultural, usually it's more personal and having to do with a bad experience. To that end, scientists developed the genetic stabilizer.
  Up to a point, all that you could really do to prevent a transformation was screening to see if you were even capable, and then therapy to help with emotional stability so that if a crisis occurred then there wouldn't be that chemical profile present in your body. This was a bit controversial since it was usually applied to teenagers (the most "at risk" group for developing powers thanks to puberty's shakeups) by their parents.
  The genetic stabilizer is designed as an implant in the brain, to inhibit the right combination reaching the bloodstream and triggering a transformation. It's highly controversial, since it's again usually applied to underage children by their parents, and usually for pretty crappy reasons like simply not wanting to deal with any potential mess.
  There are also a couple instances where the government moves to prevent the offspring of a dangerous supervillain from potentially also developing powers.