When you are not able to get an erection, the blood flow would be repeled back by the PDE 5 enzyme present in the male body. When the muscles become stiff and no blood flow happens to the penile area, you will not be able to get an erection. Before all this can happen, your brain should send signals to the erection tissues to absorb enough blood. That means, you need to have interest towards making love. When you are having interest and signals are being sent, if you are unable to get an erection, then it is the problem with the blood flow only. This medicine Kamagra Bestellen will repel the effect of impotency on men. That means, it is going to drive away the effect of this PDE 5 enzyme. So, when the effect of this enzyme is reduced, you will be able to get enough blood to the penile tissues.