This list covers 20 poisons, ranging alphabetically from “Nicotine” to “Nudibranch.” They come from plants, animals, industrial processes, and man-made chemicals, and they show up in everyday products like tobacco, insecticides, coins, and kitchen spices, as well as in medicine, agriculture, and manufacturing.

Poisons are substances that harm or kill living things when they enter the body in high enough amounts, whether through swallowing, breathing, or skin contact. Some occur naturally in plants and animals as a defense mechanism, while others are refined or synthesized for industrial and even military use. Nicotine, for example, was once widely used as an insecticide long before it became known mainly as a component of tobacco.

Below you’ll find the table with the poison, source, effects, antidote, and description of each item.

Poison: the common name of each substance, so you can quickly identify it and search for more specific information if needed.

Source: where the poison comes from, whether it’s a plant, animal, mineral, or manufactured chemical, so you understand its origin.

Effects: the symptoms and health problems each poison causes, giving you a quick sense of how dangerous it is and what to watch for.

Antidote: the treatment or countermeasure used to reverse or manage poisoning, letting you know whether a specific remedy exists.

Description: extra background on each poison, including how it’s used, where it’s found, and any notable historical or cultural details.

Poisons

PoisonSourceEffectsAntidote
NicotineTobacco plant (Nicotiana tabacum)Nausea, rapid heartbeat, seizures, respiratory failureNo specific antidote; supportive care
NaphthaleneCoal tar, mothballsHemolytic anemia, jaundice, vomitingNo specific antidote; supportive care
Nitrogen DioxideCombustion fumes, silo gas, vehicle exhaustCoughing, pulmonary edema, lung damageNo specific antidote; oxygen and supportive care
NovichokMan-made nerve agent (chemical weapon)Seizures, paralysis, respiratory failureAtropine and pralidoxime
Nux VomicaSeeds of the Strychnos nux-vomica treeMuscle spasms, convulsions, respiratory failureNo antidote; diazepam and supportive care
NitrobenzeneIndustrial solvent, dye and shoe-polish manufacturingMethemoglobinemia, cyanosis, headacheMethylene blue
Nickel CarbonylIndustrial byproduct of nickel refiningLung damage, headache, delayed organ failureChelation therapy (e.g., DMSA)
NightshadeBerries of Atropa belladonna (deadly nightshade)Hallucinations, rapid heartbeat, dilated pupilsPhysostigmine
NorbormideSynthetic rodenticideRestricted blood vessels, tissue death in rodentsNo specific antidote; supportive care
NaledOrganophosphate insecticideCholinergic crisis, sweating, muscle twitchingAtropine and pralidoxime
Nitric AcidIndustrial and laboratory corrosiveSevere burns, tissue damageNo antidote; decontamination and supportive care
NitrosaminesCured meats, tobacco smoke, some water contaminantsLong-term cancer riskNo antidote; avoidance and prevention
NembutalPentobarbital, a barbiturate sedativeRespiratory depression, comaNo specific antidote; supportive ventilation
NutmegSeed of the Myristica fragrans treeHallucinations, rapid heartbeat, nauseaNo antidote; supportive care
Nitrous OxideAnesthetic and aerosol propellant gasOxygen deprivation, vitamin B12 depletionOxygen therapy, B12 supplementation
NewtSkin secretions of rough-skinned newts (Taricha)Paralysis, respiratory failureNo specific antidote; supportive care
NarcissusBulbs of Narcissus (daffodil) plantsVomiting, drooling, tremorsNo antidote; supportive care
NitrophenolIndustrial chemical used in pesticide and dye productionFever, sweating, rapid metabolismNo specific antidote; cooling and supportive care
NickelMetal used in coins, jewelry, and stainless steelSkin allergy, lung irritation, rare organ damageChelation therapy in severe cases
NudibranchToxins sequestered from prey by sea slugsNausea, vomiting if eatenNo specific antidote; supportive care

Descriptions

Nicotine
A stimulant alkaloid found in tobacco leaves that is lethal in concentrated form, historically used in insecticides before modern regulations restricted it.
Naphthalene
A white, waxy hydrocarbon best known as the main ingredient in old-fashioned mothballs, dangerous if swallowed or inhaled in quantity, especially by infants.
Nitrogen Dioxide
A reddish-brown toxic gas produced by burning fuel, notorious for causing delayed but severe lung injury in farmworkers exposed to “silo gas.”
Novichok
An extremely potent Soviet-developed nerve agent that disrupts the nervous system, gaining notoriety after high-profile poisoning attacks in the UK.
Nux Vomica
A tropical tree whose bitter seeds are the natural source of strychnine, once used as rat poison and in small doses as a folk tonic.
Nitrobenzene
An almond-scented industrial chemical that turns blood unable to carry oxygen properly when absorbed through skin or inhaled.
Nickel Carbonyl
One of the most toxic industrial gases known, formed during nickel purification and dangerous because early symptoms can seem mild before serious damage appears.
Nightshade
A wild plant whose sweet, shiny black berries contain tropane alkaloids that can cause severe poisoning, especially dangerous to curious children.
Norbormide
A rat-specific poison developed in the 1960s that constricts blood vessels almost exclusively in rodents, making it comparatively safer around pets and humans.
Naled
A mosquito-control insecticide that disables the nervous system’s ability to regulate itself, used in aerial spraying but hazardous with heavy exposure.
Nitric Acid
A highly corrosive acid used in fertilizer and explosives manufacturing that causes immediate chemical burns on contact with skin or eyes.
Nitrosamines
A family of compounds formed during food curing or smoking that are not acutely deadly but are linked to increased cancer risk with repeated exposure.
Nembutal
A powerful sedative once common in medicine, now tightly restricted because an overdose slows breathing to a fatal stop.
Nutmeg
A common kitchen spice that becomes toxic in large doses thanks to myristicin, occasionally misused for its psychoactive effects with dangerous results.
Nitrous Oxide
Known as “laughing gas,” this common anesthetic becomes dangerous when misused recreationally, starving the body of oxygen and depleting vitamin B12 over time.
Newt
Certain newts secrete tetrodotoxin, one of nature’s most powerful toxins, making them dangerous to predators and pets that try to eat them.
Narcissus
The cheerful spring flower’s bulbs contain lycorine and other alkaloids that cause significant gastrointestinal distress if mistaken for onions and eaten.
Nitrophenol
A yellow toxic compound that dangerously speeds up the body’s metabolism, causing overheating that can be fatal in significant exposures.
Nickel
While mostly known as a common contact allergen, high or prolonged occupational exposure to nickel dust can cause more serious respiratory harm.
Nudibranch
These colorful marine sea slugs steal stinging cells and toxins from the anemones and sponges they eat, making them unpleasant or dangerous to predators.
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