Belladone Bluff

From BoardGameGeek:

Belladonna: plant in the Solanaceae family. Highly toxic, it can cause death. When properly dosed, its active substance is still used in modern medicine. To win a medical preparation, you need to add the seventh ingredient. But is it a cure with a positive score or a poison with a negative score? Face-up or face-down cards, calculation, memory and bluffing will enable you to win the game with more points than your opponent(s). -description from the publisher