Venomous Snakes

Snake Venom

Venom from King CobraNote the large yellow drop of venom
near Terry's finger

Snake venom is merely modified saliva, or a combination of many different proteins and enzymes.

The old way of categorizing venom indicated that some snakes have a neurotoxic venom (affecting the nervous system) and others have a haemotoxic venom (affecting tissue and blood). There are actually far more than two types of toxins, and countless combinations of these - myotoxins, cardiotoxins, haemotoxins, and neurotoxins, to name just a few.

No snake venom contains just one type of toxin – most snakes have a combination of toxins, and it’s this variable combination that makes reactions to snake bites from each species so different.


Toxicity is traditionally determined by how much venom it takes to kill a test animal. It is tested via the "Lethal Dose for 50%” (LD50) method - how much venom it takes to kill 50% of the test animals (usually mice).

When discussing the LD50, we must also consider the route of injection.

Under the skin. These bites are the most applicable to actual snakebites.
Into the muscle. Very large specimens of Gaboon Vipers, Puff Adders, Rhino Vipers, Rattlesnakes, Bushmasters, and South American Lanceheads (also called Fer-de-lances) are about the only snakes capable of delivering this type of bite.
In a vein. These bites are extremely rare and very, very unfortunate, as most of those are rapidly fatal.
Directly into the body cavity. These bites are even more rare for humans.

Medical uses

The dangerous effect of snake venom on humans is well known, but there are also many medicinal uses of snake venom, this specialized saliva:

Excessive bleeding
A blood-clotting protein in Taipan venom has been found to stop excessive bleeding during surgery or after major trauma.
Components of Malayan Pit Viper venom has shown potential for breaking blood clots and treating stroke victims.
Neurological diseases
Enzymes from cobra venom may be instrumental to finding cures for Parkinson's disease and Alzheimer's disease.
Cancer (various types)
An enzyme derived from copperhead venom could be used to treatment for breast cancer.
Yes, some are even used in a commercial wrinkle cream!
Read about non-venomous snakes »