Buy OSRS Magic potion(3)
The Magic potion(3) is a potion in Old School RuneScape with three doses. It gives your Magic level a boost when you drink it. This helps your spells hit harder in fights.
This potion is also a key item for high level Herblore. It is the secondary ingredient for the Extreme magic (3) potion. To make one, you need level 91 Herblore. You mix a Magic potion (3) with Ground mud runes. The Extreme magic potion boosts your Magic by about 15% plus 3, up to a max level of 106.
Extreme magic is one of the five extreme potions needed to make an Overload potion. That mix also needs a Clean torstol and level 96 Herblore. Since Extreme magic potions are not tradeable, having Magic potions on hand matters if you want to train Herblore or brew your own extremes.
Note that Extreme magic loses its strong effect in the Wilderness. There it works the same as a normal Magic potion. So a regular Magic potion(3) is still a solid pick for Wilderness trips and everyday spell casting.