This list covers 28 poisons, ranging alphabetically from “Gadolinium” to “Gyromitrin.” They come from wildly different places: metals used in medical scans, garden plants, venomous animals, household foods, and industrial chemicals. Despite their differences, each one turns dangerous under the right, or wrong, circumstances, whether that’s a contaminated meal, an accidental spill, or a bite from the wrong creature.
Poisons are substances that harm the body when they enter it in a large enough amount, whether through eating, breathing, or skin contact. Some occur naturally in plants, fungi, and animals, while others are man-made chemicals or drugs. One striking example here is grayanotoxin, a compound found in certain flowering shrubs that can turn ordinary honey into “mad honey,” causing dizziness and a slowed heartbeat in anyone who eats it.
Below you’ll find the table with Poison, Source, Effects, Antidote, and Description.
Poison: the common or scientific name of each substance, so you can quickly identify what you’re looking up.
Source: where the poison comes from, such as a plant, animal, mineral, or man-made product, giving you context on how exposure happens.
Effects: the symptoms and health problems the poison causes in the body, from mild irritation to organ failure.
Antidote: the treatment, if any exists, used to counteract the poison’s effects or manage a person’s symptoms.
Description: a short explanation of what the poison is and why it matters, written so you can understand it at a glance.
Poisons
| Poison | Source | Effects | Antidote |
|---|---|---|---|
| Gadolinium | MRI contrast dye | Nephrogenic systemic fibrosis in kidney patients, tissue deposition | None specific; avoid in renal impairment |
| Galerina | Galerina marginata mushroom | Delayed vomiting, then liver and kidney failure | Silibinin, N-acetylcysteine (supportive) |
| Garlic | Allium sativum (bulb) | Hemolytic anemia, weakness, vomiting in dogs and cats | None; supportive veterinary care |
| Gasoline | Petroleum distillate | Dizziness, chemical pneumonitis if inhaled or aspirated, CNS depression | None; supportive care |
| Gastrolobium | Australian pea-flower shrub | Cardiac and respiratory failure via metabolic blockage | None specific; experimental glyceryl monoacetate |
| Gelsemium | Gelsemium sempervirens (yellow jessamine) | Muscle weakness, drooping eyelids, respiratory failure | None specific; supportive/ventilatory care |
| Germanium | Colloidal germanium dietary supplements | Kidney failure, muscle weakness, anemia | None; dialysis for severe cases |
| GHB | Gamma-hydroxybutyrate, synthetic/recreational drug | Sedation, respiratory depression, coma | None; supportive/ventilatory care |
| Giant Hogweed | Heracleum mantegazzianum sap | Severe skin blistering and burns after sunlight exposure | None; keep area shaded, treat burns |
| Gila Monster Venom | Heloderma suspectum lizard bite | Intense pain, swelling, low blood pressure, nausea | No standard antivenom; supportive care |
| Ginkgotoxin | Ginkgo biloba seeds | Seizures, vomiting, loss of consciousness | Pyridoxine (vitamin B6) |
| Glufosinate | Synthetic herbicide | Seizures, respiratory failure, loss of consciousness | None specific; supportive/ventilatory care |
| Glutethimide | Sedative-hypnotic drug (brand Doriden) | Coma, respiratory depression, erratic sedation | None; supportive care |
| Glycoalkaloids | Green or sprouted potatoes | Nausea, vomiting, headache, confusion | None; supportive care |
| Glyphosate | Synthetic herbicide (Roundup) | Nausea, irritation, potential kidney and liver strain | None specific; supportive care |
| Golden Poison Frog Toxin | Phyllobates terribilis skin secretion | Paralysis, cardiac arrest | None known |
| Gonyautoxin | Toxic algae accumulated in shellfish | Numbness, muscle paralysis, respiratory failure | None; supportive/respiratory care |
| Gopher Purge | Euphorbia lathyris (mole plant) | Skin blistering, severe vomiting and diarrhea if eaten | None; supportive care |
| Gossypol | Cottonseed oil and plant | Low potassium, muscle weakness, infertility | Potassium supplementation |
| Grain Alcohol (Ethanol) | Fermented and distilled grain | CNS depression, impaired coordination, liver damage | None; supportive care, dialysis in severe cases |
| Gramoxone (Paraquat) | Herbicide trade name | Lung scarring, multi-organ failure | None effective |
| Grapes | Vitis vinifera fruit | Acute kidney failure in dogs | None; induced vomiting, supportive veterinary care |
| Grayanotoxin | Rhododendron and azalea nectar, “mad honey” | Dizziness, vomiting, irregular heartbeat, low blood pressure | Atropine, supportive care |
| Green Hellebore | Veratrum viride rhizome | Vomiting, slowed heart rate, low blood pressure | Atropine for bradycardia |
| Green Mamba Venom | Dendroaspis angusticeps snake bite | Paralysis, respiratory failure | Antivenom |
| Groundsel | Senecio vulgaris plant | Liver damage from long-term exposure | None; supportive care |
| Gympie-Gympie | Dendrocnide moroides stinging tree | Excruciating, long-lasting pain, allergic reaction | None; hair removal, pain management |
| Gyromitrin | False morel mushrooms (Gyromitra species) | Vomiting, seizures, liver damage | Pyridoxine (vitamin B6) |
Descriptions
Gadolinium
A metal used in MRI contrast agents that can build up in the body and cause a rare, serious skin and organ hardening disease in people with poor kidney function.
Galerina
A small brown mushroom that looks harmless but contains the same deadly amatoxins as the death cap, making it one of the most dangerous mushrooms to misidentify.
Garlic
A common kitchen staple that’s safe for people in normal amounts but is toxic to dogs and cats, damaging their red blood cells if eaten in quantity.
Gasoline
A flammable fuel whose fumes and liquid are toxic if inhaled or swallowed, capable of causing lung damage and nervous system depression.
Gastrolobium
A native Australian shrub that stores sodium fluoroacetate, making it lethal to livestock and non-native animals but harmless to the local wildlife that evolved alongside it.
Gelsemium
A pretty yellow-flowered vine whose alkaloids can paralyze breathing muscles, making even small ingested amounts potentially fatal.
Germanium
A trace element once sold as a health supplement that was later linked to serious, sometimes fatal kidney damage with prolonged use.
GHB
A fast-acting sedative sometimes misused recreationally or as a date-rape drug, where overdose can slow breathing to dangerous, sometimes fatal levels.
Giant Hogweed
An invasive giant plant whose sap sensitizes skin to sunlight, causing painful blisters and scarring that can last for years.
Gila Monster Venom
Venom delivered through grooved teeth by one of the few venomous lizards, causing a painful but rarely fatal bite in humans.
Ginkgotoxin
A compound in roasted ginkgo seeds that blocks vitamin B6 activity in the brain, historically causing seizures when the seeds were eaten in excess.
Glufosinate
A widely used weed-killer that, if swallowed in concentrated form, can cause severe neurological symptoms including seizures.
Glutethimide
An older sleeping pill largely discontinued after proving dangerously easy to overdose on, with effects that fluctuate unpredictably in the body.
Glycoalkaloids
Natural plant defense compounds like solanine that build up in potatoes exposed to light or sprouting, causing stomach upset and, rarely, neurological symptoms.
Glyphosate
The world’s most widely used weed-killer, generally low in acute toxicity but capable of causing irritation and organ stress in concentrated exposures.
Golden Poison Frog Toxin
Batrachotoxin secreted by this small, brightly colored Amazonian frog is one of the most potent toxins in nature, able to stop a heart within minutes.
Gonyautoxin
A saxitoxin-family neurotoxin produced during harmful algal blooms that concentrates in shellfish, causing paralytic shellfish poisoning in people who eat them.
Gopher Purge
A garden plant once used to repel burrowing rodents, whose milky sap irritates skin and is toxic if ingested.
Gossypol
A natural compound in cotton plants that was even studied as a male contraceptive, but can cause dangerous potassium loss and weakness with prolonged exposure.
Grain Alcohol (Ethanol)
Common drinking alcohol that, in large or concentrated doses, becomes a genuine poison capable of causing coma, organ damage, or death.
Gramoxone (Paraquat)
A powerful weed-killer so toxic that a small accidental swallow can be fatal, with no reliable antidote once absorbed.
Grapes
A healthy fruit for humans that can cause sudden, severe kidney failure in dogs for reasons scientists still don’t fully understand.
Grayanotoxin
A toxin found in certain flowering shrubs that can contaminate honey made from their nectar, producing dizzying, heart-slowing symptoms in people who eat it.
Green Hellebore
A woodland plant whose roots contain alkaloids that mimic cardiac drugs, capable of dangerously slowing the heart if ingested.
Green Mamba Venom
A fast-moving, brightly colored African snake whose neurotoxic venom can shut down breathing muscles if a bite goes untreated.
Groundsel
A common weed containing pyrrolizidine alkaloids that slowly poison the liver, historically a hazard for grazing livestock and contaminated herbal teas.
Gympie-Gympie
An Australian rainforest tree covered in tiny silica hairs that inject a toxin causing pain so severe and long-lasting it’s earned the nickname “the suicide plant.”
Gyromitrin
A toxin in certain wild mushrooms that converts to a rocket-fuel-like chemical in the body, causing seizures and liver damage if not properly detoxified before eating.