Deadly Dose

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Deadly Dose is a passive item added in The Reheated Update.


  • On pickup, spawns a PillCyanide.png Cyanide Pill.
    • Consuming a Cyanide Pill will activate the Cyanide! effect, which grants a +50% damage multiplier, +43% tear rate multiplier, +0.05 speed and +0.62 range, but will start a 60-second countdown which appears near Isaac's feet that, upon reaching 0, will instantly kill Isaac. Cyanide! can be cured by taking any other pill that isn't a Cyanide Pill, which stops the death timer while also removing all stat boosts.
  • Replaces all newly spawned pills with Cyanide Pills, only while Isaac is not under the effects of Cyanide!.
  • Pills now have a chance to spawn on room clear alongside the room's rewards, depending on these conditions:
    • If Isaac is not under the effect of Cyanide!, the chance to spawn the extra pill will always be 1/7.
    • If Isaac is under the effect of a Cyanide!, the chance to spawn an extra pill on room clear will be changed to a higher chance (1/3 at base), but this separate chance will decrease for every new Cyanide Pill taken in the run, while not already under the effect of Cyanide!.


  • Taking multiple Cyanide Pills will allow the stat boosts to stack, but also reduces the current remaining time of the countdown by approximately 66.66%, rounded up to the nearest whole second.
    • The maximum strength of the stat boosts is capped at 10 Cyanide Pills.
  • The closer the death timer of Cyanide! is to 0, a beep can be heard with each second that passes on the timer with increasing volume, before a heartbeat begins playing, and finally with a pulsing darkness flashing on screen.
  • Item effects that grant some form of invulnerability will not prevent Isaac from dying upon the Cyanide timer reaching 0 — only items that grant an extra life will prevent a game over.
  • In addition to regular pills, Cyanide Pills can appear in their PillHorse.png Horse Pill, PillGold.png Gold Pill, and PillGoldHorse.png Golden Horse Pill variants, which can only appear when replacing their regular non-Cyanide variants:
    • Cyanide Horse Pills activate the effects of Cyanide! twice when consumed.
    • Golden Cyanide Pills will only have a chance to be removed when consumed just like Golden Pills, and can be used to activate the Cyanide Pill's effect as often as possible before they disappear.
    • Golden Cyanide Horse Pills have the effects of both Cyanide Horse Pills and Golden Cyanide Pills, with each use activating the effect of Cyanide! twice, and may be able to be used multiple times.
  • Deadly Dose will not replace any regular pills that have already spawned.
  • The formula for calculating the chance for a random pill appearing on clearing a room, while under the effects of Cyanide, is equal to 1/(c + 2)%, with c being the amount of Cyanide Pills taken in the run while not already under the effect of Cyanide.
    • In effect, this means that regular pills that aren't replaced with Cyanide Pills have a very high chance to appear after taking a Cyanide Pill, but this chance decreases as the more times Isaac continuously cures and then re-uses Cyanide Pills — while not increasing this penalty for any Cyanide Pills used purely to stack Cyanide's stat boosts.
    • The extra pills dropped on room clear will always have a chance to happen while under a Cyanide Pill's effect, even if Isaac does not have Deadly Dose, in order to help prevent unfairly killing Isaac due to not spawning another pill in time.


  • Placebo.png Placebo: Placebo can be used to mimic a held Cyanide Pill's effect, which will have a 6-room charge. Regular pill effects that are mimicked by Placebo will cure a Cyanide Pill's effect as well.
  • Mom's Bottle of Pills.png Mom's Bottle of Pills: Pills created will not be replaced with Cyanide Pills, acting as another guaranteed source of pills to cure Isaac of Cyanide! in a pinch.
  • Little Baggy.png Little Baggy / Polydactyly.png Polydactyly: The ability to carry 2 pills may allow greater management of activating and curing the Cyanide! at the right time.
  • Starter Deck.png Starter Deck: Cyanide Pills can be replaced with Cards. If Isaac is already under the effect of a Cyanide Pill when picking up Starter Deck, it will replace any pill drops that would otherwise be used to cure Cyanide! with AceOfCups.png Ace of Cups, TwoOfCups.png Two of Cups, or ThreeOfCups.png Three of Cups — however, these cards will not be able to spawn pills, as they will instead be replaced with more Cups Cards, spelling certain doom for Isaac.
  • PHD.png PHD / False PHD.png False PHD: No effect on Cyanide Pills.


  • Deadly Dose is a pun on the phrase "Daily Dose".
    • The purple and green coloration of the pills may be a reference to the Daily Dose meme, an infamous animated gif depicting Piccolo from the Dragon Ball franchise participating in anal sex with Vegeta.
  • Upon taking a Cyanide Pill, there is a 1/10 chance for the "Cyanide!" pop-up text to instead say "Thanks doc!"
    • This is another reference to the Daily Dose meme, in which a common response to it was the phrase "Thanks doc".


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