The Science Behind Erectile Dysfunction

Erectile Dysfunction is a very common condition, affecting 1 in 5 men, or 4.3 million men in the UK.

However, ED can be a sensitive issue, and men can often find it an embarrassing topic to discuss. Below we provide an overview of the science behind ED, and the treatments available. 

The Science

ED is the inability to get and keep an erection at a firm enough level to have sex. Having trouble getting an erection from time to time isn’t necessarily an issue. However, if it’s a recurring problem, it can cause stress and contribute to psychological problems. Persistent ED could also be a sign of an underlying health issue.

Erections start in your brain when you see, feel or think something that gets you aroused. In most cases when we are sexually stimulated the penis produces nitric oxide. Nitric oxide activates an enzyme called guanylate cyclase which accordingly results in the production of cyclic guanosine monophosphate (cGMP). It is cGMP that is principally responsible for an erection as it directs the relaxation and contraction of the vessels that deliver blood to and from the penis.

So far so good. However, to varying degrees, we produce an enzyme called phosphodiesterase-5 (PDE5) which destroys the cGMP. This makes it harder to get and maintain an erection. This biological response of the body means that the most common cause of ED relates to circulation and blood pressure issues.

Medical conditions such as heart disease, atherosclerosis, high cholesterol and high blood pressure can also be major contributors to how much blood flows to the penis, and therefore can be major causes of ED. So too can diabetes, which can cause ED by damaging nerves and blood vessels. It's important you see a GP if you think you could have one of these conditions.

What medical treatments are available for ED?

There are medical treatments available which contain active ingredients that serve to enhance the effect of nitric oxide by blocking PDE5 from working. This allows the blood vessels transporting blood to the penis to relax, increasing blood flow to the region, thereby making it easier to get an erection.

At Man Behind The Mirror, we offer highly effective ED treatments, that are used by millions of men worldwide. The most popular treatment is Sildenafil, the generic version of Viagra, which has the same efficacy but is cheaper. Tadalafil, the generic version of Cialis, is also popular as it is faster acting and lasts for longer.

The treatments can be purchased by completing a quick online consultation so that our partner clinicians can determine their suitability for you. Once prescribed, the treatments are delivered quickly and discreetly to you within 2-3 working days. You may purchase your ED treatment here.

What alternative treatments are there?

There are organic ways to alleviate ED to some extent. Exercise has been found to improve ED problems, although for men suffering from heart disease or other significant medical conditions, they may not feel the benefit. Other lifestyle changes, such as smoking less and drinking less alcohol may also have a positive affect.

For some men (10-20%), the underlying cause of ED is due to psychological issues. For men suffering from conditions such as depression or anxiety, they may struggle to get aroused, and their brain won’t trigger the chemicals needed to instruct increased blood flow to the penis. In this event, the anxiety may be resolved by speaking with a councsellor or friends, or through meditation.

If you have any follow-up questions don't hesitate to contact us at

Written by Mike Firth, GP and Medical Director

This article is for informational purposes only and is not a substitute for professional medical advice or diagnosis. Always talk to your doctor about the risks and benefits of any treatment.