Regular Elixir's (like this one) have longer usage times. Vile Elixir and Vile Elixir +1 are virtually instant use items and mostly drop from notorious monsters. Both have the same restorative power, but the Vile ones are better in a pinch.
im not really sure but i think that this item is buyable at bastok markets in the shop beside the armor shop. i hope that this helps some people if i am correct.
If its like the other Final Fantasy games, it should give the user full health and full mp. If so, this sounds perfect for Genkai 4. Can anyone confirm what this does?