A Weak gatherer's potion is a one dose potion made in the Dungeoneering skill. It is made by adding sagewort and red moss to a vial of water. This requires level 24 Herblore and grants 65 experience in Herblore.
Using the potion boosts the player's Woodcutting, Mining, Divination, and Fishing by 3 + 2% of levels. The boost is just 3 for skills under level 50, and from 50 upwards the boost is 4.