Elixir of Life

Type: Holy Relic
The Elixir of Life is an alchemical formula that can grant it's drinker the gift of biological immortality. The Elixir of Life is said to have its origins in ancient Egypt where a prehistoric cabal of Creator Adepts labored tirelessly to develop it. It has existed in many forms and variations throughout history, known in nearly all cultures, and said to be the origin of many great heroes of history. 
The Elixir causes the drinker's body to stop the aging process. They do not become invulnerable, merely stuck in their current age. 
Physical injuries and deformities are healed by the Elixir in the following days after one drinks it. 
The exact formula is outrageously complex, often relying on rare and hard to get materials. The formula itself is closely hoarded by the most influential and richest of people. 
References:
-Elixir of Life on Wikipedia