Effect

Potion effects are conferred by food items called Potions, which can be brewed using a Brewing Stand in Beta 1.9 Pre-release 3 in order to acquire the effects.

Parameters
Potion effects are given two parameters on creation: Duration (in ticks) and strength.

History
Potion effects were introduced in Beta 1.8. although no potions where added yet so they where used exclusively for in game actions such as sprinting.

in Beta 1.9 Pre-release 2 actual potions where added and some effects got an alchemical ingredient that correspond to them and Milkgot the ability to cure and clear all potion effects. In 1.9 pre-releases 2-3 Ghast Tears where used for instant health instead of regeneration. In 1.9 pre-release 4 Glistering Melons where introduced, as the new instant health alchemical ingredient.