Pill effects can vary from one-off effects to permanent changes. Both the PHD and Lucky Foot items replace all negative stat pill effects with their positive counterparts (neutral effects such as Telepills and Bad Gas are not affected). Only one pill can be held at a time, and picking up another pill will drop whatever is held in the "Q" slot.
Negative pill effects, except for Health Down, have an 80% effect of their positive counterparts (e.g. Speed Up increases speed by 30% while Speed Down decreases speed by 24%).
Pills are on the Collection Grid (8,5) and are unlocked by finding any random pill.
If the PhD has been obtained, unknown pill types have a chance to be revealed (1/150 chance every frame). Also, if Telepills has not been identified as a pill yet, PhD will guarantee that it will not be in the pill "rotation".
Pills in the Shop cost 5 coins, 3 when on sale.
|Bad Trip||Causes Isaac to suffer 1 heart of damage, including soul hearts. Turns into a Full Health pill when health is down to 1 red heart (Warning: Bad Trip will only turn into Full Health when total health is down to one heart. In other words, Soul Hearts count). When playing as ???, Bad Trip will convert to a Full Health pill if he is at half a soul heart, rather than a full Soul Heart. Therefore, using it at a full Soul Heart will kill him. This can also happen with negative health (due to Devil Room deals) and 1 Soul Heart as any character.|
|Balls of Steel||Gives the player 2 Soul Hearts. The Soul Hearts are directly added to Isaac's health rather than spawning on the floor.|
|Bombs Are Key||Swaps the amount of bombs and keys in the player's inventory.|
|Explosive Diarrhea! (Oh No!)||Causes Isaac to leave a short trail of lit Bombs, which do not deplete his current bomb count.|
|Full Health||Fully restores all heart containers. When playing as ??? and at less than 3 soul hearts, will restore health up to 3 soul hearts. (Playing as another character with no heart containers will not restore soul hearts, rendering the pill useless).|
|Health Down||Decreases Heart Containers by 1. Changes to Health Up when at 1 heart container, regardless of current Soul Heart count.|
|Health Up|| Adds an empty Heart Container, and tints Isaac red.
|I Found Pills (And ate Them!)||
Isaac will make a "Durr..." sound and his appearance will change. (In Wrath of The Lamb, this pill is given one of two random effects: The original as shown below and "Puberty").
|Pretty Fly||Adds an Orbital black fly, which blocks enemy shots and damages other Flies.|
|Range Down||Decreases Range by 3.1.|
|Range Up||Increases Range by 3.875. Tints Isaac blue.|
|Speed Down||Decreases Speed by 0.24.|
|Speed Up||Increases Speed by 0.3. Tints Isaac yellow.|
|Tears Down||Decreases Tears by 0.28.|
|Tears Up||Increases Tears by 0.35. Tints Isaac purple.|
Wrath of the Lamb
Three new pills and four new effects are added in the Wrath of the Lamb expansion. These appear along with the previous pills/effects and are mixed in with the randomly assigned types and effects.
|Luck Up||Increases Luck. Tints Isaac green.|
|Luck Down|| Decreases Luck.
(Bug causes more chests spawned at the end of rooms.(not confirmed))
|Friends Till The End!||Gives three Attack Flies, similar to the one spawned by The Mulligan.|
|Puberty||Hair appears on Isaac's head.|
New pill colors and effects are added in Binding of Isaac: Rebirth. These appear along with the previous pills/effects and are mixed in with the randomly assigned types and effects.
|48 Hour Energy||Recharges your spacebar item and spawns 1 or 2 Lil Battery pickups.|
|Amnesia||The map is replaced with a question mark. Identical to Curse of the Lost and can be removed by items that remove curses.|
|Hematemesis||Reduces Isaac's current red hearts to 1 and spawns 1 to 4 full heart pickups. If Isaac only has half a red heart, he will be healed to 1 full heart but hearts will still be spawned.|
|I Can See Forever!||For the current floor, all Secret Room and Super Secret Room entrances will be revealed and opened when you enter the room, similar to X-Ray Vision.|
|Lemon Party||Isaac spawns a very large pool of yellow Creep. The Creep lasts about as long as Lemon Mishap but deal more damage.|
|Paralysis||Temporarily paralyzes Isaac for 2 seconds (more accurate time needed). During this time he cannot move or shoot, however his familiars will still fire.|
|Pheromones||Isaac releases a cloud of purple gas that gives all the enemies in the room a charmed effect for several seconds.|
|R U a wizard?||Isaac's eyes move away from each other. In the next one minute he will fire tears diagonally. This effect is not removed even after Isaac leaves current room.|
|Addicted||Isaac takes a full heart of damage from all sources for the current room.|
|One makes you larger||Increases the size of Isaac's sprite and decreases the pitch of Isaac's hit sound.|
|One makes you small||Decreases the size of Isaac's sprite and increases the pitch of Isaac's hit sound.|
|Percs!||Gives Isaac The Wafer effect for one room.|
|Power Pill!||Activates an effect similar to The Gamekid.|
|Re-Lax||For a short period of time, spawns poop under Isaac as he moves.|
|Retro Vision||Briefly pixelates the screen 3 times over 30 seconds.|
Holding this item eliminates the possibility of finding Stat Down Pills (does not apply to Rebirth) when consuming an unidentified pill. Unidentified stat downs will count as stat up pills, allowing two different pills to have the same effect if generated as such.
Cain starts the game with this item.
When used, this item gives you a free pill. Recharges after clearing 6 rooms.
Carrying the PHD will automatically identify unknown pills after a short delay and will also reverse stat down effects, making every stat down pill a stat up.
This Trinket, while held, slightly increases the odds of finding pills in chests and when completing a room.
Spawns 4 random pills.
Added in Rebirth, it also reverse all stat down pills to stat ups but does not identify pills.
- Bad Trip pills convert to full health pills when at 1 heart, unless you're playing as ???. If playing as ???, Bad Trip pills will convert when at one-half of a heart. Health Down pills convert into Health Up pills if you have one heart container.
- Consuming the Bad Trip pill with ??? at one Soul Heart will kill him, unlike other characters. The icon on Isaac's Last Will will be a drop of blood, similar to the one seen by dying from a Blood Donation Machine.
- If you are in the Sacrifice room with Telepills and another item you want to keep, you can avoid using the door and still keep the second item by running into it and teleporting away. When you use the pills after running, you'll slide a bit. Use that slide to pick up the item.
- Due to a seemingly rare bug the game can lag/stop when a pill named '240' has been identified with the PHD. The pill itself has no effect on the character or its appearance.
- The quote shown when picking up a pill, 'Pills Here!' is a reference to the character Louis from Left 4 Dead, who is highly known for the catchphrase said when picking up pain pills.
- The sound effect that plays when a good pill effect occurs is the same sound effect that plays when a pill is obtained in Spewer, another of Edmund McMillen's games.
- According to source code, Telepills is intended to have another 1/15 chance to teleport to Devil room/Angel room, but this doesn't work due to a bug.
- The "Balls of Steel" effect refers to the phrase that describes "having balls" as "having the confidence" for doing something, which reflects the concept behind soul hearts being faith.
- The "Friends Till the End!" pill is a reference to Edmund McMillen's comic, "The Lonely Hermit", in which a hermit befriends five maggots that live in his insides before leaving his dead body as flies.
- The "Lemon Party" pill is a reference to a shock site displaying an image of three elderly males in a bed kissing and performing oral sex. It is commonly used as a bait-and-switch link by trolls in discussion forums and imageboard communities.