Back in 2010 there wasn't any real understanding of how penis enlargement worked
We could go into the details of how we worked out the secret to what does in fact enlarge your penis but to sum it up... Jelqing works by increasing blood flow and blood pressure at the same time.
It was not until we looked at the science of "why" this worked that we understood... The penis is a part of the cardiovascular system which grows bigger when subjected to increased blood pressure and increased blood flow at the same time. Hormones can help speed up this growth but the increased blood pressure/flow is what triggers the effect in the body
I am sure you see where this is going yes?