All Elixirs, Potions, Mutagens, and magical Food and Drink that you have consumed are purged from your system. Their effects immediately end, and you are Sickened 1 until the start of your next turn.
You can immediately make a saving throw or Flat Check against any Poison effect that you are suffering from when you drink this potion, without suffering any negative effects if you Fail or Critically Fail the saving throw. You gain a Bonus to the Flat Check equal to twice the Tier of the Potion. You cannot gain this benefit from consuming a Purgative Potion again until you finish a Long Rest.