"Witchers usually drink the Blizzard potion immediately before combat. The potion is also favored in especially dangerous situations."

What is the potion Geralt drinks in The Witcher?

The fan said that according to the excerpts from the books, this potion is a mixture of materials that help The Witcher to gain full control over his body. The potion is chiefly made of veratrum, stramonium, hawthorn, and spurge.

What is the black stuff the Witcher drinks?

Witchers use Black Blood unwillingly because the potion only works when a monster begins to feast on their body. Their transmuted blood proves to be a deadly drink." Black Blood turns imbiber's blood into poison; blood becomes lethal to monsters which drink it.