Breathing pure oxygen for 90 minutes a day can be as effective as Viagra for treating impotence - with none of the side-effects and potentially longer-lasting results, new research shows.

Men who had the treatment had an average 50 per cent improvement in their erectile function. And the effects from one month of treatment lasted up to 18 months in some cases.

Erectile dysfunction (ED), an inability to obtain or maintain an erection, is experienced by around half of men aged 40 to 70, according to the British Association of Urological Surgeons. 

Nine out of ten men with ED have at least one underlying physical cause, such as heart disease, diabetes or taking certain medications, including for high blood pressure and depression (which can cause the blood vessels supplying the penis to narrow, resulting in insufficient blood for an erection).

ED is usually treated with phosphodiesterase-5 (PDE5) inhibitor drugs, including sildenafil (Viagra) and 시알리스세일구매 tadalafil (Cialis), which increase blood flow to the penis. 

ED is usually treated with phosphodiesterase-5 (PDE5) inhibitor drugs, including sildenafil (Viagra, pictured) and tadalafil (Cialis), which increase blood flow to the penis

They can be highly effective but aren't suitable for all men, including those taking nitrate drugs for angina and those with a serious heart or liver problem.

ED medications and 시알리스세일구매 nitrates both cause blood vessels to dilate - so combined can cause a sharp drop in blood pressure, increasing the risk of heart attack or stroke.