Your welcome, could always have it that the elixir of life is something like a drink form of the peaches, like a wine perhaps.
I'm not sure if you have one of them washed in the fountain of youth? Hebe was goddess of youth of the Greeks and Juventas identical to her in the Roman pantheon, they served the
nectar and ambrosia of the gods and goddesses, but it was not the drink that they served that made the gods youthful (although it probably helped to keep them immortal) it was Hebe who made them youthful, as she was believed to be able to make the old young again. I've always thought this substance made of the golden apples of the Hesperides which Gaia grew and gave to Hera and Zeus upon their marriage. Amaranth was a flower believed to grow on Mount Olympus which never died, sacred to Artemis.
The Amrit and Soma drinks of immortality in dharmic faiths. There are also chiranjivi :
http://en.wikipedia.org/wiki/Chiranjeevin
There is also Panacea a Greek goddess of the a remedy that would cure all diseases and prolong life indefinitely. Also the crown of immortality, either that of stars such as Ariadne or a laurel wreath of the Greek and Romans; the Egyptians had one too the Osiris-likened "crown of justification". The ankh.
There is also the philosophers' stone of Adam's line passed father to sons.
Norse mythology's gods had Iðunn who like Hebe seemed to be the source of their youth, rather than the apples she tended.
Like Myrddin said there is a lot of it out there.