Troll potion

Troll potion is a quest item used in the Eadgar's Ruse quest. It is made by drying out a Troll thistle on a fire to make a dried thistle, crushing it in a pestle and mortar and then adding it to an unfinished ranarr potion. You get 77.5 Herblore experience from making it.

The potion is a truth serum that the player must use on a Troll called Burntmeat in order to find out information about Goutweed. Trying to make another after quest will result in the message: "You don't need to make any more."