Defence potion (Dungeoneering)

The Defence potion (Dungeoneering) is a one dose potion only available in the Dungeoneering skill. Using the potion boosts a player's Defence level by 5 + 14% of their Defence level.

It is made by adding Featherfoil and Void dust to a vial of water. This requires level 42 Herblore and grants 89 experience in Herblore. This potion can only be made in dungeons with complexity level 5+.

Reference

 * RuneScape Game Guide: Dungeoneering - Herblore Tables