Cordyceps sinensis is a parasitic fungus native to Chinese mountain ranges. It lives on certainf caterpillars and is used for many ailments, such as anemia, irregular heartbeat, male sexual problems, and kidney and liver problems. As of 2015, there isn't sufficient evidence that it is effective for these medical conditions, says WebMD.
Cordyceps sinensis can also grow in a laboratory. It is also used to fight opium addiction and to treat coughs, weakness, undesired weight loss and ringing in the ears, WebMD explains. It is sometimes used to improve athletic performance, but evidence suggests it's ineffective for this purpose, states WebMD. Cordyceps sinensis may stimulate cells and specific chemicals in the immune system, and it may aggravate autoimmune disorders.