Did they test ANYTHING with this pack?! My sim drank this, turned elder, expected. Died of old age. *swearing* He even had the trait, I checked, so the potion "worked"... except that it didn't.
So I can't sell my potions... the ancient bloodline doesn't work so there's no point to generations I guess... and now the guy I wanted to keep around goes and dies. Well crap. :'(
This is the first and now the last time I ever buy a pack of any kind at full price.
Oh and to keep my rant on topic... I guess the answer to the question is that it does nothing.