->'''Shackleforth:''' "Glove cleaner", huh? Say... you sell much of that stuff?\\
'''Daemon:''' Now and again.\\
'''Shackleforth:''' By the way, what's in it?\\
'''Daemon:''' No trace, no odor, no taste, no way to detect its presence. And it's sure. One thousand dollars...
-->-- ''Series/TheTwilightZone1959'', "The Chaser"

When murder by poison is depicted in fiction, it never takes more than a drop of clear liquid or a pinch of white powder in order to make the victim grip their throat, cough a bit, and keel over. Quick, clean, and quiet. The reality is not so simple. To kill someone with poison, either very quickly or without arousing suspicion, is a very complex process.

Outside of highly controlled chemical munitions, there are very few substances available to the average murderer that can kill a human being as quickly and easily as the poisons of fiction. Famous poisons like arsenic, strychnine, cyanide, etc. require small, repeated doses to build up enough concentrations to kill without arousing the suspicion of the victim... in significant quantity, such poisons taste extremely bitter (hence the need for medieval food tasters). The mechanisms by which these poisons kill can cause [[BodyHorror dramatic physical reactions]] in the victim. And while it is true they were once very hard to detect, these old standby poisons are [[TechnologyMarchesOn easily and routinely detected by modern forensic pathology]].

The sort of poisons that ''can'' kill very rapidly at small doses tend to be staggeringly dangerous to the poisoner himself, not to mention exceptionally hard to come by and hazardous to manufacture.

There's also the matter of "getaway time" -- a fast-killing poison is more dramatic, but a slow-killing one is harder to link to its source.

This is generally assumed to be the kind of poison used in a case of FingerLickingPoison. Frequently has an ImprobableAntidote. May or may not [[TechnicolorToxin be purple or green]]. Naturally, part of its perfectness is usually that it works on [[UniversalPoison everything.]]



[[folder:Anime & Manga]]
* Averted in ''Manga/JojosBizarreAdventurePhantomBlood'', where both victims [[BigBad Dio]] poisons happen in steady doses over a long time.
* ''Manga/DetectiveConan'':
** Subverted: APTX-4869 is supposed to be one, and for the majority of victims has been, but certainly for our heroes it's merely a FountainOfYouth. While APTX-4869 is currently being ''used'' as a poison, it's not really a "poisoner's choice" -- when you're injecting somebody with a full hypodermic needle into a major artery, an awful lot of things become lethal (including air itself). It seems to need to be administered that way, and the people using it actually should have access to highly controlled chemical munitions. The point is that its effects on the body are so unusual (presumably due to what it was actually being developed to do) and so different from that of any publicly known drugs that forensics can't recognize the cause of death beyond the needle mark.
** They do have quite a few incidents where a person is killed by poison from a single dose administered a short time before the victim dies. You'd think the killers would want their target to drop dead somewhere other than the place they were poisoned, to throw the police off the trail and give them time to dispose of the evidence, but that never occurs to them.
* Partially averted in ''Manga/{{Naruto}}'': the Sasori's PoisonedWeapons are said to take three days to kill their victim, though they still take an improbably small amount to do so. At least he has a reason not to be concerned about their being dangerous to him (since he doesn't have a real body, and is thus immune to the effects). If it were actually a bio-weapon of some sort, it would explain why it can kill even in small doses, never kills faster, and why it is so difficult to cure. Probably targeting the nervous system, given its paralyzing effects.
* Averted in ''Manga/ShinaDark''. Poisoning Christina was done over many years.

[[folder:Comic Book]]
* In one of ComicBook/{{X 23}}'s solo comics telling how she briefly lived with her aunt and cousin, an altercation with her high school biology teacher lead to her matter-of-factly telling him the best way to poison a person undetected (and since she used to be an assassin, she presumably is speaking from experience). HilarityEnsues when she and her cousin are sent to the principal over this.

[[folder:Fan Works]]
* In ''Fanfic/MGLNCrisis'', the poison [[spoiler:Raquel Benna/Zettin drinks]] kills her within a few minutes, before help arrives.
* In ''Fanfic/IfThemsTheRules'', Arcturus poisons his wife, Melania with a perfume. [[spoiler: Played realistically as it takes a course of months for the poison to kill her, as much as a magical poison can be realistic.]]
* In the Dangerverse, [[spoiler:Narcissia Malfoy drinks a poison that gives her twenty fours to live, long enough to do quite a lot of confessing, and taking her out of Draco's life, so he doesn't feel conflicted.]]

[[folder:Films -- Live-Action]]
* Iocaine powder from ''Film/ThePrincessBride'' is odorless, tasteless, and causes nearly instant death from a dose small enough to avoid detection by the victim in a single glass of wine.
* Aversion of this trope is a major plot point in the second half of Creator/AlfredHitchcock's ''Film/{{Notorious}}.'' [[spoiler:It's even stated outright that the poisoning must be done slowly so outsiders merely think the victim is ill.]]
* Film/TheMaids: A cup of tea mixed with an overdose of sleeping pills will cause the victim to peacefully go to sleep in some ten seconds. (In RealLife, it would probably make the person nauseated enough to vomit the pills back up).
* In ''Film/{{Traffic}}'', the police informant played by Miguel Ferrer dies a few minutes after eating one bite of a poisoned breakfast. The only warning was his comment that the food "tastes like shit."
* The pure heroin that ends up killing Ignacio in ''Film/BadEducation2004''. Ignacio had become heavily addicted and was spending all of his money to obtain it, so his murderers made his death look like an overdose.
* "Luminous toxin" is the sure-fire poison in ''Film/{{DOA}}''.
* In ''Film/FromRussiaWithLove'', Blofeld pulls his first BlofeldPloy, putting Kronsteen at ease by directing his anger at Rosa Klebb for their operation's failure - then having a mook kick Kronsteen with a poisoned blade. He drops dead in a matter of seconds; Blofeld times it, observing they need to develop a faster-working poison.
* In ''Film/YouOnlyLiveTwice'' a SPECTRE mook, trying to kill Bond, accidentally poisons Aki with a drop of liquid on her lips that kills her in seconds.
* ''Film/ThatManFromRio'' begins with a thief stealing an ancient Mesoamerican statuette in a museum, killing a guard instantly with a poison-dart pistol. The police initially suspect cardiac arrest before the dart is discovered.
* Averted in ''Film/{{Skyfall}}'', where it was the '''failure''' of a cyanide capsule intended as a quick suicide that drives the main villain's quest for revenge against MI6 (Also averted is the "quick and painless" part of the poisoning - even though it failed to kill him the cyanide caused severe damage to his face and jaw bones and left him in agony).
* The cardie-toxin TH-16 from ''Film/TheBody2012''. Álex puts a few drops into Mayka's wine glass. Diluted in blood, the toxin caused a cardiac [[TimeDelayedDeath 8 hours after ingestion]] without leaving a trace or linking Álex to his victim.
* The fungus-based poison that Vann Siegert uses in ''Film/TheMinusMan'' is apparently tasteless and odorless, and kills his victims quickly and painlessly. The poison is discovered during an autopsy but without an autopsy it could easily be mistaken for a drug overdose or heart attack.

* ''Literature/MistressOfTheArtOfDeath'': The death cap mushrooms that kill Rosamund in ''The Serpent's Tale'' are mixed in with so many different kinds of harmless mushrooms that it's impossible to tell where they came from. Also, one of the effects of the mushrooms' poison is that the victim appears to get better for a time, meaning it is both slow- and fast-acting poison.
* Averted in the ''Literature/{{Discworld}}'' novel ''Discworld/FeetOfClay'', which depicts an attempted arsenic poisoning fairly accurately. Even then it wasn't to kill him either. It was to keep him from doing his normal duties.
* V.C. Andrews' novel ''Literature/FlowersInTheAttic'' has a fairly realistic version of this trope: The unwanted children's meals include powdered sugar donuts that contain traces of arsenic. Each donut contains only a minute amount of arsenic so that the children will gradually and inconspiciously die after consumption of a significant number of donuts, and the powdered sugar ensures that they won't taste the poison's bitterness. The children unwittingly hasten the death of one of them by giving him all their powdered sugar donuts because he won't eat much else from the meals.
* Averted in ''Literature/MadameBovary'' by Gustave Flaubert. Emma Bovary attempts to kill herself by swallowing a large dose of arsenic. Instead of instantaneous death, Emma endures several days of intense and gruesome illness before she finally dies. Note that this is completely in-character for Emma, who has lived her entire life [[WrongGenreSavvy believing herself the heroine of cheesy romance story]], while unfortunately only being the heroine of a painfully realistic and extremely cynical one.
* In ''Literature/ASongOfIceAndFire'', which has fairly medieval technology, the "tears of Lys" are a poison that effectively duplicates the effects of a harsh fever, leading to an apparently natural death. However, it's stated that the death takes some weeks, and it may well require repeated dosages. More messily, another poison causes symptoms which resemble anaphylatic shock or choking/suffocation--but the poison is stated to have magic in it, and it may have been sourced from an order of shapechanging assassins, so it may be justified. Other than that, all poisons are detected by food tasters, kill over time, or are not used to kill at all; for example, one character doses another with a poison that leaves her indisposed for a day or two so that he can work uninterrupted. [[spoiler:And in the case of the Tears of Lys, it also helped that the Maester in charge of healing the victim knew he was being poisoned and was ordered not to cure him. [[TheCoronerDothProtestTooMuch He subsequently covered up the death as "death by natural causes"]].]]
** In another case someone is [[MakeItLookLikeAnAccident made to look like they choked on their own food]] by being poisoned with The Strangler, which constricts the throat muscles. However during the autopsy their throat is cut open and examined, and found to contain no food.
* Addressed and averted in Simon Spurrier's ''Contract'': the main character and [[ProfessionalKiller hitman]] Michael Point drills holes in his bullets, and notes (in monologue) that conventional wisdom suggests that he fill them with poison so that his targets will die even if they were only winged. However, he goes into great detail as to why most poisons are ineffective for this kind of use, too expensive, or just plain unattainable; eventually, he decides to fill each bullet with a thousand milligrams of pure heroin - dissolved with a drop of lemon juice - in the hope that even a nonlethal shot will result in a fatal overdose.
* Subverted in ''Literature/BestServedCold'' by Joe Abercrombie. The opening scene with the master poisoner Castor Morveer starts with him telling his apprentice about the "King of Poisons", a toxin that is both completely undetectable and impossible to build up an immunity against, and should only be used against someone who is protected against all else to keep the secret. However [[spoiler: much to the apprentice's dismay, the "King of Poisons" is merely a sham concocted by Morveer in case the apprentice betrays him.]]
* Averted in the ''Literature/{{Belgariad}}'', where there is ''no'' such thing as a symptomless poison, at least to someone who's familiar with them. In fact, most poisons kill in somewhat over-the-top manners. The closest there is to a "perfect" poison, thalot (a guaranteed kill even against magic, because it poisons ''everything'' in the victim's body), has obvious symptoms and takes several days to finish off the victim. [[spoiler:And then we find out that Garion accidentally created an antidote for thalot several books earlier.]]
* ''Literature/PreludeToDune'':
** Subverted in ''Dune: House Atreides'', where Hasimir Fenring poisons Emperor Elrood Corrino IX at the request of the Emperor's son Shaddam with a chaumurky (poison that goes in a drink) that takes two years to work. The poison requires constant consumption of spice beer in order to work. Fortunately for the assassin, Elrood loves spice beer. Also, the effects of chaumurky become apparent within weeks, as the aging Emperor slowly begins to exhibit symptoms similar to senility. Given his advanced age, nobody suspects foul play.
** The Water of Life plays with this trope. The extract from a juvenile sandworm is supposed to be ''so'' dangerous that ''just one drop'' would cause sudden, violent death. It is the mark of a truly gifted individual to be able to overcome the poison, which requires enough control of the body to be able to transmute the toxin within into a non-lethal psychotropic. A woman who can achieve this has the makings of a full-fledged Bene Gesserit. A ''man'' who can achieve the same...has the makings of ''TheChosenOne''.
* In Creator/RobertEHoward's ''Literature/ConanTheBarbarian'' story "Literature/TheTowerOfTheElephant" Taurus kills several lions by blowing a powder at them.
* ''Creator/TomClancy's'' ''[[Literature/JackRyan The Teeth of the Tiger]]'' uses this form of instant undetectable poison.
* The short story "The Poison Necklace" by Miriam Allen deFord revolves around the eponymous necklace, the jewels of which are crystallized forms of various extremely toxic substances. The deaths it causes are nearly impossible to diagnose because the necklace looks entirely harmless, and the effects don't match any known poison. It was created solely as a science project, handled with gloves and kept under a bell jar, never meant to be worn.
* Subverted in Creator/IsaacAsimov's ''Literature/TheNakedSun''. Someone tries to poison Hannis Gruer, but because murder is so rare in Solaria, he gets the dosage wrong and Gruer vomits it up before it can kill him. It also creates an instant and very obvious symptom- Gruer's throat immediately burns after he takes the poison.
-->'''Elijah Bailey''': You poisoners on Solaria don't know dosages. Lack of experience. They gave him too much and he threw it up. Half the dose would have killed him.
* ''Literature/CodexAlera'':
** [[spoiler: First Lord Gaius Sextus]] is fed small amounts of atropine for years by [[spoiler: his second wife, a woman over 40 years his junior]], allowing it to gradually build up in his system. When administered in small doses, the the drug can be used medicinally. However, overdosing, even in small increments can lead to detrimental problems years later. The effects of the poison are so slow that the victim thinks that the discomfort and pain are merely signs that he's getting old.
** A combination of poisons is used to take down a corrupt politician. The assassin uses heatfire and rancid garic oil. The first one causes the heartrate to increase to induce a heart attack with the benefits of blinding the victim. The second is deadly because the rancid nature and infections it brings. The source of infection is too great for the body to overcome before fever and delirium hits, and taking days to kill at that. To cure it, it requires a healer slowly chip away at the point of infection so the victim's body can destroy it. However, this means if the healing is stopped for any long period of time, the infection will be in more places, killing the person in an hour. So, combined, even a powerful healer will fall.
* Averted in ''[[Literature/CircleOfMagic Street Magic]]''; the villain commits suicide by quick-acting poison to evade the authorities, and Briar finds the body and identifies the poison by scent, indicating that it was taken straight. In addition, he can tell from [[spoiler: Lady Zenadia's]] body language that it was a painful death.
* ''Literature/TheSagaOfTheVolsungs'': Sinfjotli drops dead instantly after drinking a cup of poisoned ale.
* Played with in ''Literature/HungerGames''. Played straight with the Nightlock berries- they result in instant death to whomever consumes them. Subverted with the venoms President Snow used to poison his enemies- they did kill the enemies, but they also gave Snow sores in his mouth even when he took the antidotes.
* In Val Mcdermid's ''Clean Break'' certain people die from inhaling cyanide as soon as they open boxes of detergent. The narrator comments that the pathologist would not have known the real reason had the person who found the first body 'not smelt bitter almonds in the room and been a fan of detective fiction'.
* In the novel ''Raptor'' by Creator/GaryJennings, there was a ''person'' who was a form of this. They looked like any ordinary person, but had been systematically fed poison their entire life, so that if you kissed or had sex with them, you'd die instantly.
* In Creator/DorothyLSayers' mystery ''Unnatural Death'', Literature/LordPeterWimsey bugs his pathologist friend for information on these; meanwhile he's chasing a murderer who's been using something like one-[[spoiler: air, injected into a vein.]]
* In ''Before the Fact'', written by Creator/AnthonyBerkeley under the NomDePlume Francis Iles, the existence of one of these is a plot point near the end of the novel. [[spoiler: After a mystery writer lets it slip one does exist, the wife of a multiple-murdrerer realizes her husband will worm the information out of the writer, and will escalate. She also realizes her husband will try to kill her, and will succeed sooner or later, so she lets him.]]

[[folder:Live-Action TV]]
* ''Series/TheBorgias'' likes this trope.
* The TV forensic show ''Forensic Files'' -- which focuses on real-life law enforcement officers solving real-life crimes without HollywoodScience forensics -- throws this trope up in the air in several episodes where a person has survived doses of poisons magnitudes larger than it would take to kill a person simply because they had been given small does over periods of years and had built up a tolerance to it. Cut to a graph of "Here's what would kill a normal person" and, six inches higher on the graph, "Here's where his/her levels were".
* Subverted in ''Series/TheTenthKingdom'', where it was established that the Wicked Queen killed Snow White's mother by slowly poisoning her as her handmaid, then married Snow White's father and did the same to him. The same was done to Prince Wendall's parents by the new [[WickedStepmother stepmother]].
* Subverted in an episode of ''Series/{{CSI}}''. The [=CSIs=] spend most of the episode looking for the instant poison that likely killed a high-stakes poker player. Grissom realizes at the end that it was a combination of factors -- a "lucky" bullet stuck in his leg he never took out, plus a daily regimen of chocolates grown in a country where the cars use leaded fuel, plus a vengeful waitress putting eye drops in his drink -- that combined to create a serious medical condition.
* ''Series/IClaudius'', has a number of poisoners, all of whom dose their victims over a number of days to make it seem like they died of a wasting illness. One of the poisoners, Martina, advises a client against using the tasteless belladonna as a poison since it leaves a tell-tale rash, but the client doesn't listen and uses it anyway. (This later comes back to haunt said client, when she and her husband are brought in for murder charges.)
* Both the above-quoted ''Series/TheTwilightZone1959'' episode and the story it's based on have "glove cleaner", "totally undetectable to all forms of autopsy". The man who sells it also sells love potions... for five dollars. He's expecting all of his customers to come back for the "glove cleaner"...
* In the ''Series/DoctorWho'' episode "[[Recap/DoctorWhoS32E8LetsKillHitler Let's Kill Hitler]]", Melody Pond poisons the Doctor with a single kiss wearing lipstick containing the Poison of the Judas Tree. It's not instantly fatal, but it's perfect in the sense that it disables Time Lord Regeneration as well as killing the body. And it's non-toxic to Melody, [[AvertedTrope averting]] the UniversalPoison trope.
* In ''Series/{{Justified}}'', Mags Bennett kills one of her henchman with poisoned moonshine. The unidentified poison killed him in under two minutes, and he apparently didn't detect any smell or taste.
* Averted in ''Series/BoardwalkEmpire''. The Commodore was poisoned with rat poison over a long period of time and in high quantities. While he is left violently ill and has to regrow his stomach lining, he still recovers to full health a few months later.
* In ''Series/BreakingBad'', Walt cooks up a little ricin to deal with Tuco. It's odorless, tasteless, requires an extremely small dose, kills within a few days after at first appearing like the flu, and is so rare it isn't tested for. Later in the series, Jesse keeps around a "lucky cigarette" filled with the stuff, just in case. [[spoiler:Ricin is used for actual poisoning only once, in the last episode of the series: Walt puts it into Lidia's tea, killing her.]]
** Later on, Gus [[spoiler:kills Don Eladio and all of his capos with a bottle of poisoned tequila. He drinks some himself, and goes to the bathroom to force himself to vomit in order to avoid the worst effects. He requires medical attention, but the rest of the cartel die within a few seconds of each other and very cleanly.]]
* Played with on ''Series/{{Copper}}''. A police sergeant fails to recognize that the dead man has been poisoned because he decides to loot the man's belongings before examining the body. The sergeant even eats the cake that the dead man has not finished eating. The police detective who takes over the case quickly realizes that the dead man and the dead sergeant were poisoned by arsenic in the cake which they failed to taste because the cake was so sweet. If the sergeant bothered to turn the body over, he would have seen the vomit and the nasty state the victim's face was in.
* Subverted once on ''Series/{{Dallas}}''. A murdered victim was poisoned, and they died just when a trope LightsOffSomebodyDies happened... Must have been Perfect Poison. However, when the murderer was confessing to their crime, they said [[SubvertedTrope the lights off had been actually a coincidence]] and that the victim had had a poison inside them long before that.
* Averted in ''Series/{{Merlin 2008}}'' when Merlin reluctantly poisons Morgana in order to break a spell that's been placed over Camelot. After he tricks her into drinking from a flask of water containing hemlock, it takes a while for her to feel the effects, and is a very slow and painful process once she starts dying.
* ''Series/{{Castle}}'' came incredibly close, albeit thanks to some special (but not rare) circumstances. A popular talk-show host named Bobby Mann was found dead of a suspected heart attack. However, Castle, who was just on his show and had Mann whisper in his ear that he thought his life was in danger, suspects murder. Two tox screens came back clear, but at Castle's insistence, they dig further, and find the truth: Bobby Mann was taking a very powerful medication for depression. The medicine reacts fatally with anything fermented. Knowing this, they realize the cranberry juice he was drinking was spiked with (fermented) balsamic vinegar, almost undetectable under the circumstances.

* An old-time radio "Five Minute Mystery" titled [[http://www.otr.net/r/fmin/73.ram The Radium Murder Case]] tells of a murder exposed because, according to the investigator, the poison used would instantly knock out the victim upon contact with the tongue. In this case, the poisoning was openly stated but the perpetrator attempted to claim the poisoning as a suicide.
* Averted in ''Radio/TheAdventuresOfHarryNile''. In on case, after [[spoiler:the culprit feeds Harry rat poison]], he has enough time to comment that he feels funny, [[spoiler: sigh upon realizing he's been poisoned, and then go to get his stomach pumped at the hospital.]]

[[folder:Tabletop Games]]
* Realistic use of poison in most tabletop systems is extremely rare. This is mostly due to how roleplaying systems work -- poisoning someone over weeks or months is usually hard to make work mechanically, and usually won't be on the list of how PlayerCharacters [[WhenAllYouHaveIsAHammer off their opponents]].
* In earlier versions of ''TabletopGame/DungeonsAndDragons'' such as 2nd edition, poison would kill the victim instantly if they failed their saving throw.
* ''TabletopGame/DungeonsAndDragons'' 3.5 has a selection of poisons that deal a random amount of ability damage to one and only one ability score over two "doses". These damage doses happen exactly one minute apart regardless of the type of poison used. Terms such as dosage, dilution or long-term exposure never enter into it. Poison-users ''are'' in danger of poisoning themselves during application, however.
* ''TabletopGame/{{Pathfinder}}'', being the SpiritualSuccessor to the above version of ''D&D'', has updated the poison rules in response to this trope. Poisons can now have a various onset time anywhere between six seconds and a day, and some poisons can last indefinitely. One particular poison can kill someone (by Constitution drain) over an arbitrarily long period of time.
* Averted in ''TabletopGame/{{Exalted}}''; the poison rules are designed around inflicting only one die of damage per time interval (which are generally in the hours), and can only inflict a limited amount of damage per dose. Multiple doses just extend how long the poison can last, while still only inflicting one die per interval. The most dangerous poison in the game (made from the concentrated hatred of [[EldritchAbomination demon gods]] and tremendously rare and expensive) would still take about seven seconds to kill most people (and would be rather obvious about it).
* In the RPG for ''TabletopGame/LegendOfTheFiveRings'', the Scorpion Clan (the underhand clan) sourcebook noted that while such poisons exist in universe, their opponents have gotten good enough to detect such compounds, which would point back to them. The book lists about 25 'natural' compounds that characters could use instead, few of which are fast, but all can be effective over time, and details are given for each. At the end of the section, it reveals the real names of all but 2 of them, being based on real world natural poisons.

* Creator/{{Shakespeare}} was in love with this trope. It seems like half his tragedies involve somebody getting poisoned with "the deadliest poison known to man".
** ''Theatre/{{Hamlet}}'': is particularly striking.
*** Laertes returns from abroad to find that his father had been murdered. Fortunately, he just so happens to have purchased a phial of Super Poison that he's going to use for the old "dueling with poisoned swords" trick. I guess that poison was available at souvenir stands all over France, next to the T-shirts and shotglasses.
---->'''Laertes:''' "I bought an unction of a mountebank, so mortal that, but dip a knife in it, where it draws blood no cataplasm so rare, collected from all samples that have virtue under the moon, can save the thing from death that is but scratched withal." Act IV, Scene VII.
*** The ghost of King Hamlet also goes into lavish detail about his own death by poisoning -- a poison that was dripped into his ''ear'' while he slept, and resulted in the most agonizing death throes, as well as hideous sores popping out all over his body.
** Surprisingly common Super Poison also appears in ''Theatre/RomeoAndJuliet''. Although as that poisoning was voluntary it probably wouldn't have mattered if it had had a distinctive smell or taste.

[[folder:Video Games]]
* In ''VideoGame/{{Achaea}}'', a large number of poisons are available and widely used in combat. Most only cause [[HitPoints hit point damage]] or a [[StandardStatusEffects status effect]], but Voyria is invariably lethal...At least it should be, if it didn't take a full thirty seconds to do its work, during which the player [[{{Anvilicious}} receives SIX warning messages describing unmistakeable symptoms]] (mild fever, nose bleeding, bloody vomit, heavy breathing) and has only to take a sip of MagicAntidote to instantly save himself. As everyone carries antidote with them, the only practical way to kill someone with Voyria is to prevent the victim from drinking or injecting medicine.
* Averted in ''VideoGame/HitmanBloodMoney'': one of Agent 47's primary weapons is a syringe that can be used to inject targets at the jugular or to poison food. For efficiency's sake, instead of using a single poison, a mixture of chemicals is used: sodium pentothol, pancuronium bromide and potassium chloride. Since this is the exact combination of chemicals used in lethal injection executions, the victim dies quickly and noiselessly.
** Which only kinda makes sense. In lethal injections they use multiple [=IVs=] so the poisons don't mix beforehand and undergo a process called precipitation. A fancy way of saying they get all waxy and won't go in. And it can still take two hours for the victim to die. It would work better to just use one of the first two (the more fast acting drugs) and strangle the person after they pass out.
** Probably the reason that 47 carries around a reel of piano wire. However, ''Blood Money's'' use of poison makes more sense than the previous game, ''[[VideoGame/HitmanContracts Contracts]]'': in several levels, you're forced to look for poisons in the surrounding area and dose people's food or drink with it, and weedkiller or rat poison aren't exactly painless or quiet.
*** It should be noted the the poison in Blood Money ''isn't'' undetectable; kills with poison count as regular kills rather than accidents.
** In ''[[VideoGame/Hitman2SilentAssassin Silent Assassin]]'', one of the levels has as its target the son of a wealthy and powerful Japanese criminal. One way of achieving the kill is to sneak into the kitchen where a fugu dish is being prepared, and reintroduce the highly toxic liver to the dish. However, the toxin in the game works considerably faster than in real life.
* In ''VideoGame/FinalFantasyTactics'' [[spoiler:Dycedarg]] slowly poisoned his father over many years, which the rest of the family mistook for an illness.
* ''VideoGame/DragonQuestVII'' has the whole debacle in Verdham where [[{{Yandere}} Kaya]] is slowly poisoning her husband. The poison she uses is a powder which she keeps in a vial around her neck; her husband is convinced it's his ''medicine'', and you have to get the bottle away from her and its contents tested to prove otherwise.
* ''VideoGame/DragonAgeOrigins'' has a whole skill based around the creation of poisons and toxins to coat weapons with. These work instantly, though they generally have effects other than instant death (slows the target, does damage over time, paralyzes or stuns for a few seconds, etc.). Only Quiet Death can instantly kill, and even then it only has about a 5% success rate.
** The same goes for ''VideoGame/TheElderScrollsIVOblivion''. There are also instantly fatal poisoned apples you can sneak into people's inventory, if they don't have any other food in there, they will eat the apples eventually and die.
*** Actually, the poisoned apples are not ''quiiite'' perfect; they only cause a permanent damage health effect of 10 per second. If you have a high enough health regen, you can survive, though it'll make the game much harder as you can't go to sleep again (can't sleep while being hurt). Cue the game ending instantly if you're forced to go to sleep, as your health regen drops to zero while sleeping as well.
* Somewhat similarly to the above example, in ''VideoGame/TheElderScrollsVSkyrim'' there is a powerful poison plant called Jarrin Root that is said to kill instantly. It causes 200 points of poison damage, which is more than enough to kill any low-level enemies. But when combined with other poisonous reagents and a high Alchemy skill the damage can range in the thousands.
* In an ending cut from ''VideoGame/JadeEmpire'', Sky dies from drinking poisoned wine.
* In ''VisualNovel/{{Cinders}}'', Cinders can choose to kill her stepmother Carmosa with a poison that's stated to produce no noticeable ill effects in its victim until they suddenly drop dead of a seeming heart attack a couple of hours later. Its unusual effects ''could'' be handwaved as the result of it being crafted by a fairy or witch with access to magical powers, though. Plus, Cinders's poisoning attempt can fail spectacularly if Carmosa doesn't trust her and has the breakfast Cinders serves her tested for poison, which indicates that the poison's "perfect" qualities don't include untraceability.
* [[VideoGame/OneThousandAndOneSpikes 1001 Spikes]] explains the dart traps' quality of being able to kill instantly is because of them being poisoned. The Scorpions also qualify, because a single sting from them is immediately fatal.
* In ''VideoGame/AviaryAttorney'' someone dies frothing at the mouth moments after grasping a rose and exclaiming that they've been pricked by the thorns. The defense attorneys lampshade this trope, being unsure if any poison that strong exists. Turns out the real mechanism was a wolfsbane derivative [[spoiler: mixed with caramel and made into the filling for fancy chocolates]], and took somewhat longer. Still undetectable, and strong enough that forty-five minutes after eating the wrapper which still bore traces of [[spoiler: the chocolate]] another character is hospitalized.
* ''Franchise/AceAttorney'': In the third case of ''Trials and Tribulations'', as well as the fourth case of ''Apollo Justice'', the victim dies from cyanide poisoning and from a (possibly) fictional poison, respectively, but in both cases the killer was more interested in having the person dead than hiding the method from the police (as far as ''what'' killed him, at least). As a result, the victim did not have a swift silent death, but instead gave full display of the poisons' physical reactions for all to witness, and the police have no trouble in figuring out what killed the victim.

[[folder:Web Comics]]
%% * ''Webcomic/MinionsAtWork'': [[http://www.minionsatwork.com/2009/02/minions-151-hard-to-swallow.html An early retirement plan with a fresh, minty after-taste!]]
* In the ComicBook/ChickTract "Party Girl", a man who drinks a poisoned drink dies in less than four minutes.

[[folder:Web Original]]
* ''WebOriginal/ProtectorsOfThePlotContinuum'': On their wiki, the PPC refers to this as "Ye Olde Poisonous Poison."

[[folder:Real Life]]
* The assassination of [[http://en.wikipedia.org/wiki/Alexander_Litvinenko Alexander Litvinenko]], a prominent critic of then-president of Russia UsefulNotes/VladimirPutin, was someone's ''attempt'' at using a PerfectPoison which backfired spectacularly. Litvinenko was killed when someone sprinkled polonium-210 into his tea cup. Polonium-210 has many advantages: it can be carried safely in a vial of water without detection, and while death is certain the initial symptoms don't immediately suggest poison, giving time for the poisoner to make a clean getaway. Furthermore, unlike most radioactive substances, Polonium-210 only emits alpha particles which cannot penetrate even a sheet of paper, thus making it invisible to normal radiation detectors (and requiring it to be physically ingested to work as a poison). However they made one big mistake: they thought it was undetectable. While the technology to detect Polonium-210 didn't exist in Russia, it ''did'' in the West. Oops. Furthermore, whoever did the actual poisoning seemingly didn't realize how much Polonium-210 contaminates. Simply uncapping the vial is enough to leave detectable amounts. This made Litvinenko's murder one of the most unsubtle in history, with investigators simply following the trail of radioactivity back to the murderer's hotel room.
* Genghis Khan's father is believed to have been killed by drinking poisoned milk during a meal with rival Tatars.
* The [[http://en.wikipedia.org/wiki/Richard_Kuklinski Ice Man]] said that he would kill people by putting large amounts of cyanide in drinks, spilling it on them, and walking away.
* [[http://en.wikipedia.org/wiki/Karen_Wetterhahn Karen Wetterhahn]] died after exposure to a tiny drop of dimethyl mercury on her gloved hand on August 14th, 1996. However, the death was long and drawn out, and she only began showing symptoms in December of 1996. Three weeks after showing symptoms she slipped into a vegatative state alternating with periods of extreme agitation which was horrifying to watch with all the thrashing and stuff; however, doctors said she likely wasn't in pain - her brain was well beyond the point of transmitting the likes of pain signals. She did not actually die until June 8, 1997 when she was removed from life support. [[CaptainObvious In this case the poison wasn't untraceable.]] Weaponizing it would be tough: While a cheap supermarket squirt gun full of the stuff would ensure the deaths of targets better than a rocket launcher, we're talking something ''so'' toxic that if you ''know what it smells like,'' that means you've most likely taken in enough of it that YouAreAlreadyDead.
* The rumors spread about Lucrezia Borgia by her family's enemies often included a reference to a poison she made called "la cantarella." Even if the Borgias ''did'' have people poisoned, this particular substance was alleged to be ''such'' a perfect poison that it could not in fact have been real (according to some versions of the story, the poison could be fine-tuned to kill the victim [[ExactTimeToFailure a specific preset time]] after ingestion).
* The real-life poisons abrin and ricin are both very deadly, and can easily be manufactured from common ornamental plants, making the origin of the poison difficult to trace. In the assassination of [[http://en.wikipedia.org/wiki/Georgi_Markov Georgi Markov]], identifying the organisation that was likely responsible (the Bulgarian Secret Police) was not done by tracing the ricin, but by investigating the capsule used to deliver the poison - a matching pellet had been recovered in the case of Vladimir Kostov, another Bulgarian defector who was attacked ten days before Markov's murder, although in his case the pellet appeared to have been damaged before it entered his body and did not retain enough ricin inside it to cause his death. Neither poison kills as quickly as the trope demands, but they're about as close as real life gets.
* Subversion: [[DeadlyGas Nerve gas]], when aerosolized, kills in concentrations as low as a single droplet dispersed into an entire roomful of air, and in this form is both transparent and odorless. However, it causes a death so horrible, painful [[ArsonMurderAndJaywalking and noisy]] that it's plainly obvious what did it, and there isn't a great deal of detective work required to find out who did it - the range of suspects able to manufacture it (essentially, only governments who are not signatories to the [[http://en.wikipedia.org/wiki/Chemical_Weapons_Convention Chemical Weapons Convention]]) is pretty limited. Fictional works which feature the use of nerve agents as poisons usually have the poisoner steal their supply from military stockpiles (e.g. ''[[Film/TheRock The Rock]]'', Creator/MichaelCrichton's ''Binary''.) This is increasingly unlikely in the real world, as the aforementioned CWC came into effect in 1997 and prohibits the "development, production, acquisition, retention, stockpiling, transfer and use of all chemical weapons" in 188 countries. (Of the countries that are not signatories, all but one - South Sudan - have been accused of possessing chemical weapons.)
* The closest thing to a perfect poison is something that could be [[MakeItLookLikeAnAccident passed off as an accident]]:
** Amanita mushrooms, or death caps, could conceivably be eaten voluntarily by someone who doesn't know their mushroom lore.
** Improperly prepared lima beans or tapioca can be deadly to eat.
** Someone with a life-threatening allergy could be poisoned with the food they're allergic to, and that could be passed off as an accident.
** A form of poison which is hard to trace to a suspect is [[BoringButPractical an excess of nicotine]] (injected in a dose much larger than usually lethal) in one of the victim's cigarettes. By the moment the victim drops dead, the said cigarette is already consumed, and autopsy reveals [[CaptainObvious only that he or she had a lot of nicotine in the body]]. It's very unreliable for an assassin who does not have permanent access to the victim's personal belongings and therefore it has hardly been used. Also, a lethal dose of nicotine is usually a blatant giveaway of the foul play unless the toxicity screen test is provided several days after death.
** In countries and social strata which have a problem with counterfeit alcohol, methanol is a near-perfect poison. It could conceivably end up accidentally in a counterfeit bottle of spirit (there are more than enough ''accidental'' methanol poisonings caused by non-malevolently contaminated rotgut). It's nearly indistinguishable from ethanol and produces the same effects as ethanol, followed by certain death if ingested in a typical recreational dose. This method of poisoning was used in the short story [[ "Bargain"]] by A.B. Guthrie, Jr.
* Several animals produce toxins that could qualify as this. It should be noted that most of these critters are bright and colorful, which in nature means: ''Hands off.'' It should also be noted that these toxins wouldn't be a practical way for humans to poison each other. Very few people (mostly scientists) have access to these poisons and venoms[[note]]the difference being that ''venom'' is injected while ''poison'' is absorbed through the skin, lungs, digestive system, etc.[[/note]], making them easy to trace.
** ''[[http://en.wikipedia.org/wiki/Chironex_fleckeri Chironex fleckeri]]'' (a kind of box jellyfish commonly called the "sea wasp") produces one of Earth's deadliest toxins. As per this trope, the venom takes effect instantaneously: the sea wasp's sting causes excruciating pain and an intense burning sensation (like a red-hot iron). It's only deadly when the sting area is significantly big, but in fatal cases, the victim can die within two to five minutes if untreated. An average sea wasp carries enough venom to kill sixty adult humans. Even worse, unlike other similarly venomous animals, the sea wasp is nearly invisible underwater. And yes, ''Chironex fleckeri'' is found along the northern coast of [[DeathWorld Australia]] - but also along the coastlines of Vietnam, Indonesia, and the Philippines.
** Other animals with quick-killing poisons and venoms include the [[http://en.wikipedia.org/wiki/Blue-ringed_octopus blue-ringed octopodes]] of the ''Hapalochlaena'' genus, as well as many varieties of cone snails and [[http://en.wikipedia.org/wiki/Poison_dart_frog poison dart frogs]], all of which can kill within minutes if you touch them (except poison dart frogs, which can only kill you if the poison is ingested or enters the bloodstream through a cut or a [[PoisonedWeapons poison dart]]). In fact, ''[[http://en.wikipedia.org/wiki/Conus_geographus Conus geographicus]]'' is nicknamed the "cigarette snail" because its victims are said to only have enough time to smoke a cigarette before they die.
*** However, the toxins from poison dart frogs are far from perfect - they work by paralysing muscles, including those used for breathing. While this means they are quickly fatal if untreated, a victim can be kept alive by artificial or mouth-to-mouth respiration and will recover entirely in a few hours as the poison wears off.
** Pufferfish (''[[http://en.wikipedia.org/wiki/Tetraodontidae Tetraodontidae]]'') deserve a mention here too. As per this trope, the symptoms appear almost immediately after the meat is eaten. First, the victim's lips and tongue go numb. Then come the dizziness and vomiting, followed by rapid heart rate, lowered blood pressure, numbness all over the body, and [[AndIMustScream paralysis until death comes four to twenty-four hours later]]. Poisoning someone with pufferfish meat (or ''fugu'' in Japanese) wouldn't be particularly practical, though. The only people allowed to serve ''fugu'' are licensed chefs, and even if a ''fugu'' poisoning was passed off as an accident, it would almost certainly lead to public shame and a revocation of the chef's license. (Unfortunately, in Thailand, pufferfish meat is often served in lieu of other fish because it's cheaper and because fewer people there are aware of the danger.)
* The [[https://en.wikipedia.org/wiki/Poison_laboratory_of_the_Soviet_secret_services poison laboratory of the Soviet secret services]] created a poison gas called carbylamine-choline-chloride, or C-2. It was said to be [[SovietSuperscience odorless, tasteless, and could not be detected autopsy, yet was potent enough]] to kill within ''fifteen minutes.'' Eyewitnesses claimed that the gas also caused victims to [[TransformationHorror physically change]], withering away and becoming quieter and calmer before death.