Improbable Elixir, Combine Elixirs and Permanent Elixir

[Charlesfire]

Is it possible to combine two Improbable Elixir and make then permanent?

[shroudb]

If their combined level is half of your max, then yes.

At level 18 that you have those feats it's limited to level 7 "potions" (since that'll make the combined elixir level 9)