Light therapy; exposure to bright artificial light, often used to treat seasonal affective disorder; could also boost men's libido.
It is estimated that up to one quarter of men have a low sex drive; defined as lack of interest in sex. Anxiety, stress, depression, and other psychological factors can be causes of low sexual desire in men, as well as a reduction in the male sex hormone testosterone.
Solutions that are available to them involve lifestyle changes such as improvements to the diet, regular physical exercise, or change to the medications that they take. In a small number of cases, testosterone replacement therapy, through patches or injections, can be proposed. As for medicines such as viagra, they do not boost libido, but can help men get an erection.
Now, Italian scientists say that using a light box, which some people use to treat seasonal affective disorder (SAD), could improve the sex lives of men with low sexual desire. They took inspiration from the natural fluctuation of sexual interest with the seasons, reasoning that this might be related to sunlight and tested the idea on 38 men. Half were given regular treatment with the kind of full-spectrum white light box that mimics daylight for sufferers of seasonal affective disorder. The other half were given a placebo box modified to give out much less light.
Before treatment, both groups averaged a sexual satisfaction score of 2 out of 10. Afterward, the group exposed to the bright light reported scores of around 6.3, Fagiolini says. The other group showed an average score of around 2.7 after treatment.
The researchers also found that testosterone levels increased in the men who had been given active light treatment.
"The increased levels of testosterone explain the greater reported sexual satisfaction,” Fagiolini says. “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."
The next step will be to replicate these findings in larger studies. Fagiolini told IBTimes UK that this research could also be interesting to treat female sexual dysfunction. Indeed, the scientists will measure in future trials levels of LH, a key female hormone.
It will be some time before a clinically approved treatment emerges from this work - it may not be suitable for people with eye conditions, as bright light could have a negative health impact.
The scientists will also need to explain in greater details the effects of bright light on hormones. So far, they believe that the reason light therapy works is that it inhibits the pineal gland in the center of the brain which triggers the production of more testosterone.