Out of all the wild future tech in those books, a universally accessible easily controllable gland capable of pumping out whatever molecules the body could use, from hormones to party drugs, still stands out as the single most beneficial thing possible.
As a kid I had an idea for a pill that would do that. I had no idea how it would work if course, but I thought one day in the future we could have a pill that you took that detected issues with the body and produced the needed drugs to fix it, so nobody needs to take a bunch of pills or the wrong pills. I'll have to read it.