Sex is improved by shining bright lights at men, new study finds

Spending half an hour with a 'light box' each morning led to hugely increased levels of testosterone

This man perhaps should have switched that light on

Shining bright lights at men might help them with flagging sex drives, according to a new study.

Exposure to light helps boost men’s levels of the male hormone testosterone and increases sexual satisfaction, according to the new research.

Many men experience low sexual desire after the age of 40. Some studies have estimated that up to a quarter of men might be hit by problems, which seem to depend on their age among other factors.

But that flagging sex drive seems to vary with the seasons. That led scientists to suggest that it might be a consequence of the amount of ambient light, and that sex drive was reduced in the winter because it was so dark.

That led them to shine daily doses of bright light at men, and explore the way that it changed their libido.

Researchers at the University of Siena recruited 38 men who have been diagnosed with having low libidos.

Half of them then spent every morning for two weeks in a room with a light box, which can emit bright white light at people and simulate the effect of more sun.

Those men that spent more time with the box found that their testosterone levels had gone up significantly. And, accordingly, they were much more satisfied sexually, they reported.

"We found fairly significant differences between those who received the active light treatment, and the controls,” said lead researcher Andrea Fagiolini.

"Before treatment, both groups averaged a sexual satisfaction score of around two out of 10, but after treatment the group exposed to the bright light was scoring sexual satisfaction scores of around 6.3 - a more than three-fold increase on the scale we used. In contrast, the control group only showed an average score of around 2.7 after treatment."

The average amount of testosterone in the group that didn’t have the lights shone at them didn’t change. But the men that were treated with the light box had their levels rise from 2.1 nanograms per millilitre to 3.6.

"The increased levels of testosterone explain the greater reported sexual satisfaction," said Professor Fagiolini. "In the northern hemisphere, the body's testosterone production naturally declines from November through April, and then rises steadily through the spring and summer with a peak in October. You see the effect of this in reproductive rates, with the month of June showing the highest rate of conception. The use of the light box really mimics what nature does."

He added: "We believe that there may be several explanations to explain the underlying mechanism. For instance, light therapy inhibits the pineal gland in the centre of the brain and this may allow the production of more testosterone, and there are probably other hormonal effects.

"We're not yet at the stage where we can recommend this as a clinical treatment .. however if this treatment can be shown to work in a larger study, then light therapy may offer a way forward. It's a small study, so for the moment we need to treat it with appropriate caution."