Sulfur is an active item in The Binding of Isaac, added in the Repentance DLC.

Grants Brimstone for the current room.

If Sulfur has already been used in the current room, or Isaac has Brimstone, it instead grants +1 damage, ×1.2 damage multiplier, and widens the laser for the current room.

This page shows the latest information as of the new Repentance+ (Online Co-op) DLC.
To see information about this item for the previous Repentance version, check this page instead.

This item contributes towards the Leviathan transformation. Collecting 3 items from this set will grant Isaac flight and +2 Black Hearts.

Sulfur can be found in the following item pools:

The following tags are applied to this item:

The following special synergies and interactions for Sulfur have been documented.

* Note that not all possible synergies and interactions are listed here.

Below is the Internal Item Description as shown in-game.
Note that some stat changes are not displayed here. Please see the main description for the full effects.

Sulfur

• Grants Brimstone for the current room
• Activating twice in the same room grants a more powerful version of Brimstone
• Abyss: x1 Brimstone locust 1x Isaac's damage
• Book of Virtues: x1 middle wisp - 2 hp - 1 damage
• Book of Virtues: Short-range Brimstone attack

• Check out the item description on the external Isaac Wiki.