Most people who pick up sildenafil online buy it to help fight the symptoms of erectile dysfunction, but one of the most infamous studies on the little blue pill has suggested that it can help save mountain climbers’ lives.

The study, published in the Annals of Internal Medicine suggested that sildenafil could increase the body’s ability to exercise at high altitudes, specifically at an altitude of 17,900 feet (5,500m) at Mount Everest Base Camp.

Why this works is similar to how sildenafil can help with erectile dysfunction, as well as other health conditions.

Sildenafil And The Heart

Sildenafil has a long history of being used to help people with certain types of heart conditions. In fact, the initial intention for the drug was to be a treatment for high blood pressure and angina, with the side effect of inducing erections.

Whilst the drug eventually became primarily used to treat ED, the way in which it does this means that it can treat other heart conditions, and indeed Pfizer themselves branded Revatio as a form of sildenafil intended to treat pulmonary arterial hypertension.

The reason for this is that sildenafil is a PDE5 (phosphodiesterase type 5) inhibitor, which relaxes your muscles and allows your blood vessels to open up more, increasing blood flow around the body and reducing blood pressure.

Opening up your blood vessels is not only good for maintaining an erection, or for helping reduce the strain of your heart and lungs in certain cases but can also help in situations where the air is much thinner.

On Top Of The World

The higher you travel in the world, the less air there is to breathe, and this can have serious side effects known collectively as altitude sickness.

Typically your body needs time to adapt when rapidly climbing as the body is commonly working harder with less air getting into it.

At its worst in manifests in the form of oedema, which is where fluid accumulates either in the lungs (for pulmonary oedema) or on the brain (for cerebral oedema).

Both of these are life-threatening and are believed to be caused by hypoxia, where blood vessels are constricted and it is harder to breathe enough oxygen.

The study attempted to highlight this effect by having 14 mountaineers taking sildenafil both at sea level after intentionally induced hypoxia and then at Base Camp.

Whilst it did not increase oxygen saturation (how much oxygen is in your blood), it did reduce blood pressure, and overall helped the mountaineers work harder.

By reducing the hypoxia, it can reduce the risk of the harsher effects of altitude sickness, at least according to the study.

Interestingly, this is an effect likely only noticeable at high altitudes for athletes, as they already have dilated blood vessels that widen during exercise. As well as this, it did make headaches worse for people in the study who already had them.

Sildenafil has had a fascinating history and been used to treat many interesting conditions, but helping mountaineers breathe at the top of a mountain may be one of its more unique uses.