Poisoning was the favoured method for housewives dispatching their husbands in the Victorian era. Commonly used was cyanide – a rat poison widely available at the local chemist! Asides from it’s availability and deadliness, cyanide was also favoured for being – at the time – quite difficult to detect after death. The decline of cyanide poisoning came about with the invention of the Prussian Blue test, a relatively straightforward way of testing for the presence of cyanide.

The poisons we’ll be looking at here are a little different though. The most potent poison on this list is up to 50,000 TIMES more potent than cyanide.


Strychnine, like most poisons, comes from a plant – Strychnos Nux-Vomica. It causes the muscles to spasm uncontrollably and is known for causing an excruciating death. Due the effect that Strychnine has on muscles, victims often end up with what is called a ‘Rictus Grin’, where the muscles in the face contract to make it look like the affected person is smiling. It’s known as the poison of choice for CRIME fiction authors such as Agatha Christie and Arthur Conan Doyle due to the dramatic reaction it causes. We’d wager that the Joker would also find this poison quite useful…


Again, Ricin is a plant-based poison found in the beans of the Castor Oil plant. That’s right, the same oil you can cook with! Don’t worry though, only the beans carry the toxin…  It was famously used to assassinate Bulgarian dissenter Georgi Markov on Waterloo Bridge, London. Markov was walking along and felt something hit the back of his right thigh – he turned around and saw a man picking up an umbrella. Later that day, Markov was admitted to St James’ hospital. He died there four days later. A small pellet was found in the back of his leg that had been filled with DEADLY Ricin. It had been fired from an air gun hidden in the umbrella the man following him had been carrying. It’s suggested that the Bulgarian Secret Service had a hand in his murder, as well as the KGB. Ricin is also known as Breaking Bad protagonist Walter White’s poison of choice.


Batrachotoxin is the neurotoxin that gives the Poison Dart Frog its (VERY well deserved) name. For years, hunters have carefully caught these frogs and heated them over a fire to sweat out the poison. They then use this to coat arrowheads, meaning that they only need to graze an animal to kill it. Interestingly, Poison Dart Frogs bred outside of their natural habitat are not actually poisonous – it’s filtered out from a part of their diet in the wild and safely (for the frog!) excreted through their skin. This poison is INCREDIBLY toxic – 2 micrograms of poison per kilogram of flesh is enough to kill you, which is an amount roughly the size of two grains of table salt.

VX Nerve Gas

The only manmade poison on this list, as well as the only one to be considered a weapon of mass destruction, VX was discovered in the 1950’s at Porton Down in England. It is a nerve gas that causes paralysis of the muscles, affecting the diaphragm and heart. With the ability to be absorbed through the skin as well as being over 5 times more potent than the infamous Sarin gas, this makes VX a DANGEROUS contender.


Pufferfish poison – Tetrodotoxin. Pufferfish is a delicacy in the Japanese dish Fugu but this tasty meal can be FATAL. If organs containing the poison are incompletely removed, or if the organ breaks, the dish becomes a deadly dinner. It stops muscles from reacting to signals from the brain and causes your diaphragm and heart to stop working. As little as 0.35 micrograms could kill a human.

Botulinum toxin

Botulinum toxin is the most dangerous poison on this list. In fact, it’s the MOST POISONOUS substance we know of. Causing ‘flaccid paralysis’, your muscles simply stop working. Your heart and lungs cease to function and death occurs rapidly. Just 1 nanogram of Botulinum per kilogram can kill a human. Extrapolating from its effect on mice, an intravenous dose of just 10-7g would be fatal to a 70kg person – that is to say 0.0000001 grams. Reckon you’ve heard of Botulinum before? That’s because it’s the key ingredient in BOTOX.