Marek's Antidote can be obtained only from Marek himself in Chapter 5. It is the end goal of the quest Marek and Lothander and is needed to cure the party of a deadly poison. It can be used up to ten times and must be used by each party member individually.
In-Game Description Edit
Marek's potion looks to have 10 doses. More powerful than a normal potion of antidote, this potion would neutralize even the most lethal of poisons.