A nasal spray could treat erectile dysfunction up to ten times faster than Viagra, scientists say.

Viagra was revolutionary when it hit shelves in the 1990s, but experts say it has one drawback — it takes up to an hour to act, potentially ruining a spur-of-the-moment sexual encounter. 

A new experimental nasal spray treatment, named SPONTAN, triggered an erection in as little as five minutes in early trials and could be available in the US in the next two years.

Lee Rodne, who heads up the Australian company developing the spray, suggested it could be the most significant advancement in helping men keep an erection since Viagra emerged. 

About 30million men in America suffer from erectile dysfunction, or the inability to get or maintain an erection during sexual activity.

When a man gets an erection, the smooth muscles around the penis relax, allowing blood to flow into the region. 

In those with erectile dysfunction, this system may be disrupted by heart disease or emotional issues such as stress and anxiety limiting blood flow to the penis.

Viagra works by relaxing the muscle cells in blood vessels supplying the penis, allowing more blood to flow into it. The drug also thins the blood making it flow more easily.

When aroused, the increase in blood flow allows a man to have a stronger erection.

The drug must be taken orally and takes 30 minutes to an hour to kick in because it is absorbed by the digestive system.

But doctors at Brisbane-based bio company LTR Pharma are now working on a spray version dubbed SPONTAN.