It will require you to be a billionaire, or a world leader. Most likely someone important or powerful will buy the patent and then keep it back for their cronies. They need their slaves workers to be ignorant and desperate. Living a lot longer means they gain more knowledge and have more incentive to ensure the remainder of their lives are lived well. Billionaires want people downtrodden enough that they will do anything to ensure food for their children.
It's possible a billionaire will give this to workers since it seems to improve productivity into older ages. Buuuut I'd bet dollars to doughnuts that receiving this drug is contingent on signing a contract to work for their mega corporation until retirement. Said retirement age will be pushed out as more usable lifespan is gained from this drug until you retire. Oh, no you don't get retirement benefits and most likely people receiving this drug can't participate in 401ks or similar retirement schemes since they will have an "unfair advantage" of having so much longer to accure interest that other workers simply can't compete! (but we're not going to limit user's stock trading because that's what the rich use, shhhh)