Millions of men suffer from erectile dysfunction (ED), a sexual condition characterized by the inability to achieve and sustain an erection.

Viagra has been the “game-changer” when it comes to the treatment of ED, but there are other options too, like penis pumps, which can offer a lifeline.

With pills like Viagra, Cialis, or Levitra, many men experience side effects. However, with penis pumps, the risk of side effects is extremely low. But again, for some men, penis pumps might not be the best option.

NetDoctor, part of the Hearst UK wellbeing network, spoke to Dr. Luke Pratsides, a GP at online men’s health clinic Numan, and Dr. Tet Yep, consultant urologist for London Urology Associates at The Princess Grace Hospital, to understand whether penile pumps work when it comes to treating ED.

Also called a vacuum erection device, a penis pump is a kind of non-drug treatment available for men with ED. A penis pump functions by increasing blood flow to the penile organ, helping users to get and maintain an erection.

A penis pump consists of “a plastic tube that fits over the penis, a hand or battery-powered pump attached to the tube, and a band that fits around the base of the penis once it is erect, called a constriction ring,” Dr. Pratsides says. The pump works by using suction to draw blood into the penile pagan.

He explains, “The blood fills the blood vessels in your penis, causing them to swell so the penis gets bigger and harder for a temporary period. To use the pump, place the tube over your penis and pump out the air using the electric or hand pump attached.”

Penis pumps usually work best for men who have moderate erectile dysfunction. They may not be the best choice for men with mild symptoms. A penile pump may not be as effective as Viagra pills for men with a severe degree of erectile dysfunction.

So, one should always check with their doctor before using penis pumps.

“For many men, penis pumps are generally effective and allow them to maintain erections sufficient enough to have penetrative sex,” says Dr. Pratsides.

However, the duration of the erection may vary depending on the use of the constriction ring.

Dr. Yap says, “Erectile dysfunction is a common problem among older men, especially after prostate surgery and prostate cancer treatment. While oral treatments are often recommended as first-line treatments, penis pumps are highly effective in inducing erections, regardless of the cause of the erectile dysfunction. They’re also very safe.”

“Compared to drug treatments for erectile dysfunction, a major advantage of the penis pump is that it has a low risk of systemic side effects, and therefore the potential to be used in a greater number of patients,” Dr. Yap continues. “The penis pump can be used to ensure multiple erections on a daily basis.” The article originally appeared on NetDoctor, UK.