Minecraft wiki entry for Combat, associated text: Lingering potions can be used to hinder enemies or deal damage, but use them sparingly. Lingering potions of Healing or Regeneration can let you get closer to zombies or zombie pigmen and receive the Healing or Regeneration boost while damaging your target. Lingering potions that have increased time make for hit and run tactics, a good strategy if you are low on health. If you are being chased by a group of hostile mobs and you have a Lingering potion of Instant damage, remember that you still can take damage from the area of effect cloud.