so, cordyceps is the mushroom / fungus.
here’s the 2 products I narrowed my purchasing down to.
Cordygen5 http://www.amazon.com/dp/B001MM3J30/ref=pe_175190_21431760_C1_cs_sce_3p_dp_1
I opted for the Cordygen5 based on price. I found a lot of good reviews on it, outside of Amazon. The Optygen HP has lots of great reviews on Amazon. http://supplementreviews.com/millennium-sport/cordygen5 http://reviews.bodybuilding.com/Millennium_Sport/Cordygen5/