Weapon Poison can be applied, after which the player will gain the ability to poison an opponent. The poison effect lasts for 2 minutes and 30 seconds before another dose has to be applied for the poisoning effect to continue and deals between 13% to 25% of your ability damage per hit.
After the Evolution of Combat update, existing weapon poison potions were replaced with 3 dose poisons. However the old weapon poison version is still obtainable from monsters as a drop, such as Warped tortoises and Ankous. This version does not have the ability to let the player to poison others, nor apply the poison to any weapons (the original function). In order to solve this problem, drop the potion and it will automatically change to weapon poison (3). This has yet to be fixed. These unconverted potions retain the examine text of "For use on daggers and projectiles."