A Limpwurt root are used to make both regular and super strength potions in the Herblaw skill. It can be obtained as a drop received from killing monsters, such as Hobgoblins or Giants. It may be exchanged for 5 Limpwurt Root certificates and vice versa. During the Temple of Ikov quest, 20 limpwurt roots are given to Winelda in exchange for her teleporting you across a lake of lava once.
Players may create a regular strength potion themselves by using them on an unfinished Tarromin potion. Alternatively a limpwurt root, red spider eggs, and 5 coins may be given to the Apothecary in Varrock, in order to make strength potions. This is a feature that was essential to various groups of RuneScape Classic players who played before the release of the Herblaw skill. This method was of extreme importance to individuals and clans who tended to play the game specifically in order to engage in PKing.
A limpwurt root is also used with an unfinished Kwuarm potion to make Super strength potions, which requires level 55 Herblaw and grants 125 experience.