Cordyceps is an ancient Chinese herbal remedy made from the fungus Cordyceps sinensis. This is sometimes called the caterpillar fungus because it feeds on caterpillars and in its later phases can resemble a caterpillar. Cordyceps has been used for centuries in China as a general tonic. However, it is very expensive because it grows only at very high altitudes in the Himalayas of Tibet and China.

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