This is how an erections is achieved.

If there is not enough of this chemical blood vessels can not open up and blood flow to the penis gets affected negatively which affects the rigidness of your erections. This helps penis muscles to relax so that the blood vessels can dilate or open up and allow more blood to flow into the erectile tissue making the penis swell. The secretion of this chemical declines with age and this results in erectile dysfunction in men. Nitric Oxide and Erections - Get Hard Erections Naturally Most men are not aware of this but nitric oxide plays a pivotal role in helping you get hard and firm erections. L-arginine is an amino acid that helps in the release of this chemical in the blood vessels. No wonder it is often called the Nature's Viagra. Food sources of L-arginine include animal protein, dairy, poultry products, nuts and beans. Moreover, there are some natural or herbal supplements for men that not only contain L-arginine but also a whole.

When you get sexually excited, this chemical is secreted in the walls of the blood vessels that supply blood to the penis.