Binding of Isaac: Rebirth Wiki

Added in Repentance

Neptunus is a passive item added in The Binding of Isaac: Repentance.


  • When Isaac is not firing tears, a charge bar will start to fill up. Holding down the fire button will release all stored tears in rapid succession.
    • The charge time and maximum tears per charge scale with Isaac's tears stat, with higher tears charging faster and having more.


  • While at 0 charge, Isaac fires at his normal tear delay, essentially meaning there is no downside.
  • Rapid tapping the fire button will not empty the charge, and can be used as a permanent massive increase to fire rate.
  • This item has no observable effect when used as Tainted Lilith Tainted Lilith or Tainted Forgotten Tainted Forgotten.


  • Chocolate Milk Chocolate Milk: Neptunus' passive charge overrides Chocolate Milk's active charge. Tear damage is determined by how charged Neptunus is.
  • Kidney Stone Kidney Stone: Tear bursts stack, firing a very large number of tears in combination with each other.


In-game Footage[]



  • Neptunus, as well as Jupiter Jupiter, was designed for the original Antibirth mod, but never actually implemented until Repentance.


PC Hard mode only 9LEW RG2W (Planetarium adjacent to spawn)

PC Hard mode only LCHN M6M8 (Planetarium adjacent to spawn)

PC Hard mode only DBLL Z867 (Planetarium adjacent to spawn)

PC Hard mode only MDVC 7994 (Planetarium adjacent to spawn)

PC Hard mode only Y2Z0 3P70 (Starting item as Eden)

PC Hard mode only SNQP D766 (Planetarium next to spawn, with Lost Contact in a normal room on third floor)


Bug Bug! When combined with both Chocolate Milk Chocolate Milk and Marked Marked or Soy Milk Soy Milk, Isaac is prevented from firing tears.