The 15 most poisonous substances that exist

Whether natural or artificial, there are different chemical compounds that, if they come into contact with our body, can cause serious problems and even death from poisoning.

As Paracelsus , the father of toxicology, said: “the poison is in the dose” . That is, all substances can be poisonous depending on the dose ingested. In other words, even water can be a poison. And, let’s see what happens to you if you drink 10 liters in a row. Nothing good.

Now, in nature (and even some synthetic ones) we can find chemical substances that, even at extremely low doses, can be lethal or, at least, cause very serious health problems. Indeed, we are talking about what we popularly know as poison.

From chemicals produced by frogs capable of killing 1,500 people to toxins released by bacteria, flowers from exotic plants, pesticides, chemicals and fish poisons, there are hundreds of substances out there capable of killing an adult human in a matter of seconds. minutes .

For this reason, in today’s article, we will undertake a fascinating journey throughout the world of toxicology to find the most poisonous substances, of very varied origins, that exist, ordered from least to most lethal.

We recommend you read: “The 20 most poisonous animals that exist”
What are the deadliest poisons?
A poison is, broadly speaking, a substance of a chemical or biological nature that, after being introduced into the body through different routes (inhalation, ingestion, bite, sting…), causes serious health disorders, including death.

In this sense, poisons can be mineral, animal, vegetable or artificial (in fact, all medicines, at high doses, are toxic). Next we will see (they have tried to be ordered from least to greatest lethality, but we must bear in mind that this depends on many factors) the most poisonous substances in the world.


Present in different species of poisonous mushrooms of the genus Amanita and similar, amatoxin is a hepatotoxic poison. When the mushroom is ingested, the toxins travel to the liver and kidneys, where they block protein synthesis in these cells.

This protein blockage causes very serious symptoms, with extreme pain in the abdominal area, nausea, vomiting, intense diarrhea, bleeding, etc., all because the toxin is slowly destroying the kidneys and liver . Within two days of ingesting the toxin, he either falls into a coma or goes into cardiac arrest. Either way, the result is death.


We continue with poisons of biological origin. And in this case we focus on anthrax, a toxin produced by the bacterium Bacillus anthracis , which has a fatality rate of 85%. Famous for being used in the 2001 bioterrorist attacks on the United States , this substance is one of the deadliest in the world.

This bacterium is found naturally in the soil, although people can become infected by inhaling its spores or when they reach the blood through a wound. Depending on this, it can occur with a lung, intestinal or skin disease. Be that as it may, once the bacteria produce these toxins in our body, whether due to meningitis, septicemia (toxins in the blood) or respiratory problems, death comes a few days after the first symptoms.

Chlorine trifluoride

We are dealing with a colorless gaseous chemical compound used as an ingredient for the fuel of spacecraft, capable of corroding glass and that, in contact with water, causes a highly explosive reaction. Therefore, it goes without saying that its inhalation is totally lethal. Therefore, it must be stored in special containers, since the fact that it is colorless is a problem.


Lead is a highly toxic metal that was used in paints, pipes, cans, and many other products years ago, but is now completely banned due to its toxicity. And it is that prolonged exposure to this substance causes intoxication in which, even when the metal is in low quantities in our body, it generates delayed development, loss of fertility, headache, spontaneous abortions, hypertension and even neurological damage. irreversible. After years of exposure, it can be fatal .


Arsenic is one of the most famous poisons. And it is that, as we see in the famous movie “Arsenic for compassion”, it is tremendously effective when it comes to killing a human being. (Note: no need to check). In addition, the risk of being exposed to it is, in certain countries of the world, quite high.

Prolonged exposure to this metal, which is diluted in the untreated waters of less developed countries , can cause cancer. But acute poisoning with a high dose causes vomiting, diarrhea, abdominal pain, muscle cramps, and (if quantities are high) death.


Tetrodotoxin is the poison of the puffer fish. Native to the waters of China, Japan, Korea, the Philippines and Mexico, the puffer fish is one of the most poisonous animals in the world and, without a doubt, one of those with the most powerful toxin. Some are more poisonous as they inject more venom, but this is the one with the most potent toxin, second only to a frog which we’ll see later.

The tetradotoxin, synthesized in a gland and released through its spines, attacks the nervous system, causing coordination problems, slurred speech, seizures, headaches, nausea, arrhythmias, and, in most cases, death. at 24 hours.


Strychnine is a poison of vegetable origin that is extracted from the seeds of a tree of the species Strychnos nux-vomica and that has a powerful neurotoxic effect. It has traditionally been used as a pesticide to kill rats in particular. In any case, accidental ingestion in humans also causes serious problems, since in addition to neurological damage and seizures, at high doses it can be fatal.


Famous for being used by some Greek philosophers to make “shots of death,” cyanide is a powerful poison that can be fatal in a matter of minutes. But the most surprising thing is not this. The most surprising thing is that this poison is extracted from the seeds of fruits that are always in our kitchen . Apples, almonds, cherries, apricots…

So why don’t we die with every dessert we eat? Because this toxin is so common in nature that our body has learned to assimilate and neutralize low doses. Now, when taken in high amounts, this cyanide binds to iron in the blood, preventing red blood cells from carrying oxygen. Death by suffocation comes within a few minutes.


Mercury is a liquid metal at room temperature and highly toxic, which is why mercury thermometers have been completely banned for years . It can occur in three forms: elemental (the one that was in thermometers), inorganic (mercury is diluted among other chemical substances) or organic (by eating food contaminated with mercury).

Depending on how we become intoxicated and how long the exposure is, symptoms can include breathing difficulties, paranoia, insomnia, weight loss, neurological damage and even death.

Sarin gas

Being 500 times more toxic than cyanide , sarin gas is one of the most powerful poisons in existence. Discovered by accident in 1938 in Germany by a group of scientists investigating pesticides, it didn’t take long for it to fall into the wrong hands.

Since then, sarin gas has been used as a chemical weapon, especially by the Syrian regime. This colorless and odorless gas (has no smell), has a powerful neurotoxic effect. Just half a milligram inhaled is enough so that, in a few minutes, the nervous system is blocked and death occurs due to cardiorespiratory arrest.


What could be more poisonous than sarin gas? Well, there are still the first five places, so here we go. Ricin is a plant-derived toxin present in the seeds of the Ricinus communis plant, a plant used to extract its oil, which obviously does not contain this toxin (nor is there any risk that it does).

Be that as it may, its seeds contain one of nature’s most powerful poisons. Whether inhaled, ingested, or injected into the blood (there have been cases), ricin inactivates the ribosomes in our cells, so protein synthesis stops. This is catastrophic for the body, so death comes from multiple organ failure and cardiorespiratory arrest .


VX, also known as Agent X, is a synthetic nerve gas that was designed by the British Army to be used as a chemical weapon in warfare, although it was never used. Be that as it may, it is a horrible poison that inhibits the enzymes that control the nervous system, causing it to go completely out of control.

The loss of control over the body and the convulsions are only a prelude to the inevitable death, which comes shortly. If the amount inhaled or absorbed through the skin (even by protecting the respiratory tract, intoxication is possible), is extremely low, death can be avoided, but irreversible neurological damage will always remain.


It seems unbelievable that an apparently harmless yellow frog of just over 5 centimeters in size is capable of producing a more toxic poison than those that have been designed in laboratories for war purposes. But it is like this.

Batrachotoxin is the third most powerful poison in the world and is synthesized in the skin glands of the golden dart frog, a species of amphibian native to the jungles of Colombia and Panama. There is enough poison on the surface of their skin to kill 1,500 adults. If this is not surprising, consider that 0.00005 grams of this toxin can kill an adult elephant .

And the thing does not end here. And it is not even necessary to touch the frog for the toxin to reach our body. Cases have been recorded of people who have died of intoxication (the toxin causes muscular paralysis that leads to death) for having touched surfaces that the frog had passed over and that had been contaminated with batrachotoxin.


Maitotoxin is a poison with similar lethality to batrachotoxin, though slightly more potent, earning it second place on this list. This toxin, produced by Gambierdiscus toxicus , a species of dinoflagellate, a single-celled protist species that inhabits some tropical waters.

This microorganism that is part of the plankton produces an incredibly powerful poison that, at doses of just a few nanograms, causes a heart attack in a few hours

Botulinum toxin

We made it to number 1 on this list. Botulinum toxin is the most powerful poison in the world. It might seem like running away from her should be our top priority. Well no. We inject it into our faces to look younger. That’s how we are.

Botulinum toxin is produced by the bacterium Clostridium botulinum and is so deadly that 0.00000001 grams is enough to kill an adult . Poisoning (which is usually due to the ingestion of food contaminated by the bacteria, especially poorly treated homemade preserves) causes botulism, an extremely lethal disease in which the toxin attacks the nervous system, causing, in the best of cases, extreme pain and temporary muscular paralysis, although in most cases, death by suffocation is inevitable.

Botox is basically botulinum toxin at extremely low doses that is injected into the face to promote paralysis of certain facial muscles and achieve (sometimes) a more youthful appearance, as it stimulates the muscles to always be in tension, causing that there are no wrinkles.

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