I found a provider of Icariin with a 60% extract. Most, if not all, that you will find are 10% to 20% low doses to feel and see the impact on NO.
At these levels Icariin acts as a PDE5 inhibitor which provides for great pump and vascularity. Also, it act just like Viagra in that regard as an added benefit it provides for better and stronger erections.
I Googled "Icarrin PDE5" and found a number of clinical studies that support all of this and more.
Have any of you taken Icariin at this level of extract and if so what were your experiences?