Both lab cultivated Cordyceps fungi called c.militaris, and nature grown sinensis Cordyceps look different. As they are made up of different components, but. Both contain Cordycepin the bio-active substance. The lab cultivated militaris have been shown to have an even greater amount than c. sinensis therefore offering faster effects when dealing with symptoms.
Cordyceps Militaris is cultivated from collecting spores out in nature and, by using special technology, they can be grown and reproduced without the need to infect an insect. Therefore, making c.militaris a vegan alternative to those that grow out in the wild. Using a controlled environment also reduces the toxins that could pollute the mushroom whilst out in the wild.
The process is delicate. If the spores are cultivated over and over from the originally collected specimen, they stop growing mushrooms. This means that each batch is carefully managed and has a very high fail rate, meaning each crop can see up to a 50% loss because the spores are so delicate.
The benefits often spoken about in Traditional Chinese Medicine are found in both mushroom species.
A study titled, Chemical Composition and Nutritional and Medicinal Value of Fruit Bodies and Submerged Cultured Mycelia of Culinary-Medicinal Higher Basidiomycetes Mushrooms, published in June 2014 concluded:
The fruit body biomass of C. militaris cordycepin content reached 1.743 mg/g dry weight.
The limited supply and over-harvesting of Tibetan Cordyceps has made it an endangered commodity. C.militaris is a much more sustainable variety for getting Cordycepin into the diet.
Cordycepin is also being studied by the pharmaceutical industry in phase 1 trails for Leukaemia amongst other things
http://www.hindawi.com/journals/ecam/2015/174616/Ashok K. P. and Kailash C. S. (2011). Traditional Uses and Medicinal Potential of Cordyceps sinensis in Sikkim.
Jingjing S., Yingwu W., Meiyu T., Guangsheng C., Hongkai X., Hanxiao G., Yang L., Di W., and Lesheng T. (2015). Studies on the Antifatigue Activities of Cordyceps militaris Fruit Body Extract in Mouse Model.