Cialis is an erectile dysfunction drug. Could it also help you live longer?

Tadalafil – better known by its brand name Cialis – is one of the most commonly prescribed drugs for erectile dysfunction.

But in some biohacking and wellness circles, it's increasingly being repurposed for an entirely different reason.

Online clinics and influential figures are promoting it as a kind of all-purpose longevity drug – delivering benefits for the cardiovascular system, brain and even athletic performance.

The drugs aren't approved for preventing heart attack and stroke, let alone for extending life.

However, the enthusiasm does reflect growing interest among some experts in the field of cardiology and men's health that tadalafil and other drugs in its class could have a legitimate role in preventive health.

"It's a serious area of discussion," says Dr. Robert Kloner , chief science officer at the Huntington Medical Research Institute and a professor at the University of Southern California .

"Cardiovascular disease remains the number one killer – and we have these drugs that may have a potential benefit, but we have to learn a lot more."

Tadalafil belongs to the same class of drugs as sildenafil, i.e., Viagra – with the primary difference being that its effect lasts considerably longer.