Are you really sure you want the answer?

To my gathered knowledge and experience there are only five things that will make you look younger than you currently are without side effects or backlashes.

Three of those things are currently in this glass. They are quite easy to figure out what they are – one should be blatantly obvious. The other two can be realized by means of deduction and a library. The chemical reaction is very important.

The fourth thing is a consumable, but of a completely different nature. It could be tricky to figure out as it requires a high level of intellect in order to be properly deduced – its efficiency can be enhanced with the help of very advanced external equipment for processing. But even the ancient Egyptians could synthesize it.

The fifth could be perceived as a consumable if one resonates properly. But that one is the sought after secret.
The thing so few discover.
No wonder why they save it for last in many secret societies.
It must be properly understood in order to be prepared, as it could be corrupt or tainted so easily. The ‘distillation process’ is very precious.

Neither of them are a body fluid (exclusively) nor drug (in the conventional sense).