Basic Cordyceps Sinensis Facts
Cordyceps sinensis is just one species in a genus of hundreds. All species are parasites. This species is found only on the Tibetan Plateau. Other cordyceps species grow all over the world, mainly in Asia in humid tropical forests.

It preys specifically on the larvae of several species of ghost moths in the Thitarodes genus. Spores infect the larvae while they live underground before pupating. The spores germinate and mycelium grows, killing and mummifying the larva/caterpillar. Eventually a fruiting body grows from the mummified larva and pops above ground, reminiscent of something from an awesome science fiction movie.

The fruiting body of Cordyceps sinensis is technically not a mushroom but an ascocarp. Ascocarps are created by Ascomycota, a Phylum of fungi defined by their reproductive structure. For the purpose of this article we won't argue semantics, as most people refer to cordyceps as a mushroom as well.

The fruiting body is usually up to 4 inches (around 10 cm) long and .2 inches (1/2 cm) wide. Unlike a typical mushroom, these are curved and club shaped like a small cane. They're usually orange or brown. In addition to the English term "caterpillar fungus" there are other interesting names. In Tibeta it is referred to as yartsa gunbu. The Chinese name is dong chong xia cao (meaning "winter worm, summer grass"). The Latin name cordyceps means "club head", and sinensis is "from China".

Although written record of Cordyceps sinensis use appeared in Traditional Chinese Medicine centuries ago, it wasn't really noticed in the West until recently. The last two decades have seen a great increase in research on cordyceps as a medicinal mushroom.

Cordyceps Fungus Health Benefits
There are many reported cordyceps health benefits. Some of these include:
. Cholesterol reduction 
. Stimulation of the immune system 
. Faster recovery from bronchitis and respiratory diseases
. Increased efficiency and stamina of the circulatory system 
. Anti-tumor properties 
. Liver protection and enhanced recovery from chemotherapy 
. Sexual potentiator 
. A general body adaptogen, resulting in more energy, strength, and stamina

The reasons behind some of these benefits are still not fully understood. Yet research has found some promising proof behind cordyceps claims. A few of the helpful constituents found are:
Sterols - Alcohols of the steroid group. Believed to lower cholesterol, reduce the risk of heart disease, and possibly have some anti-tumor properties.
Polysaccharides - Complex carbohydrates made up of chains of sugars. Known to stabilize blood pressure, have an effect on free radicals, and stimulate the immune system.
Nucleosides - Organic molecules that are the converted into building blocks of the genetic material DNA and RNA. Nucleoside drugs are sometimes used to treat cancer.

One of the most useful things that Cordyceps sinensis appears to do is the simple act of oxygenation. The fungus dilates the airways in the lungs, resulting in more oxygen to the blood. Thus more oxygen reaches every cell of the body, resulting in better cell function and greater energy levels.