If this is for real, then... DUDE.
If it IS 100% effective, and reversible, then... DAMN. MonkeyBoy will be strongly encouraged to get this injection when he's 13. He can reverse it when he's ready to have kids, if he and his partner choose to make babies.
And speaking of, he's awake. So I'll leave you with the article: The Revolutionary New Birth Control Method For Men. Go read, be amazed, get excited, and find that doctor in San Francisco who wants to bring this to the FDA. Let's make this happen! Soon!!
"About half of all pregnancies in the US are unplanned. Come up with a better contraceptive and the likely results are all good: fewer unwanted kids, fewer single parents, and fewer abortions."