And while the remedy may sound shocking, the only sensation volunteers felt was a mild tingling as the current passed through tissue.
Is the treatment already used?
The technique, called functional electrical stimulation, has been used for nearly 40 years to treat other conditions, such as multiple sclerosis.
Many MS sufferers suffer a condition called drop foot, where they struggle to lift their foot properly from the ground due to the damaging impact of the disease.
But firing a low-level current into the leg "reawakens" muscles and nerves that control this movement.
Stroke victims too can benefit from the same therapy.
The devices used cost around $5,600 each.
Now a team of researchers in Brazil has tried out the stimulation therapy on men with impotence who did not get better taking drugs like Viagra.
Erectile dysfunction: The facts
One in ten men suffers erectile dysfunction at some point in their lives.
Some studies suggest more than a third of those over 40 are affected.
Although drugs like Viagra have revolutionised treatment, around 35 per cent of men who take them see no improvement.
These patients are often left using cumbersome vacuum devices, or undergo surgery to have penile implants that can be inflated when needed.
But a tiny jolt of electricity could be a better solution.
How was the study carried out?
Researchers at The Federal University of Health Sciences in Porto Alegre, Brazil, recruited 22 men, aged 40 to 65, with severe erectile problems.
None were on Viagra-like drugs at the time and all were asked to attend clinic twice a week for a month for treatment.
But while half got the genuine electric shock therapy, the rest received a dummy, or placebo, treatment, where the electrodes were attached and a red light lit up on the power-pack but no current was generated.
Sexual response in both groups was measured using a recognised scale, called the International Index of Erectile Function.
The results, in the latest International Journal of Impotence Research, showed those given the dummy treatment saw little or no change in their scores.
But of the 11 given a small charge, three regained the ability to get spontaneous erections, five saw significant improvements in the scores on the index and the last three saw no response to the treatment.
It's not clear exactly how mild electric jolts boost sex drive but animal studies show it can trigger a process which leads to an increase in levels of nitric oxide, which dilates blood vessels and boosts blood flow to the genitals.
An "interesting" study
Dr Geoff Hackett, chairman of the British Society of Sexual Medicine, said the treatment could potentially help some men but only if much larger studies prove it really does work. He said: "There are a few unanswered questions."
Dr David Goldmeier, sexual medicine expert at Imperial College London, said: "This is an interesting study.
"But the number of patients is small and there was no long-term follow up to see if the benefits lasted."
