Viagra has quite literally changed the lives of millions of men around the world dealing with erectile dysfunction, but you'd be hard-pressed to find anyone who thinks the little blue pill is perfect. Once you dose up, you're going to have to plan your sex around all the side effects, such as headaches, hearing loss, dizziness, and stomach pain. Romantic.

The good news is researchers say they've come up with the most viable alternative to Viagra in 15 years, and it offers a longer-term solution that can be used by men who don't respond to traditional drugs: extra-corporeal shock wave therapy (ESWT) - in other words, zapping the penis with low-intensity sound waves.

As New Scientist reports, earlier this month, several research teams presented their findings on ESWT treatments at a meeting of the European Society for Sexual Medicine in Spain, and the evidence from the past few years is looking really promising. 

Back in 2013, a team from the Rambam Medical Centre in Haifa, Israel reported that in a trial with 20 men who had been experiencing erectile dysfunction for at least three years, 15 of them were having spontaneous erections that were strong enough to achieve penetration six months after undergoing ESWT treatment.

They're now conducting a larger study with 60 men to see how the effects progress over a two-year period.

In 2014, a team led by urologist Anne B. Olsen from Denmark's Viborg Hospital recruited 112 men with erectile dysfunction who found it impossible to have penetrative sex without medication, and split them up into two groups - one received five weekly doses of the low-intensity sound waves to six sites along their penis, and the other group got placebos.

They found that 29 men (57 percent) in the ESWT group were able to obtain an erection and have sexual intercourse without the use of medication some five weeks after the treatment, while only five men (9 percent) in the placebo group showed similar results. When the patients were followed-up on 12 weeks after the treatment, 28 percent were still able to get erections without medication.

"The treatment is patient friendly, has no side-effects requiring treatment, and can be used for all patients," the team describes in the Scandinavian Journal of Urology. Another plus? Unlike Viagra, the treatment gives men with erectile dysfunction the ability to have spontaneous erections.

And late last year at the American Urological Association's 2015 annual meeting, the results of recent multinational clinical trials were discussed, and ESWT was deemed to be a "safe, effective, and well-tolerated treatment for erectile dysfunction".

So why would sound waves have an effect on a man's ability to get an erection? One of the researchers from Israel, Ilan Gruenwald, told New Scientist that, "The treatment seems to encourage the growth of new blood vessels in the penis," which in turn encourages healthy blood flow to return to the organ.

It's still early days yet, but these are exciting times if your life is affected by erectile dysfunction. While some clinics around the world are already offering the treatment, it's yet to be approved in the US, but that could be happening sooner rather than later, if promising results keep rolling in. "I've been a skeptic, but I'm becoming a believer," says Trinity Bivalacqua from Johns Hopkins University.

Now if they can just figure out how to make the situation better for women who have their own sex-related problems, that'd be great too.