A drug-free treatment for seasonal depression may also light up your sex life. New research shows that daily light therapy boosts testosterone levels and triples sexual satisfaction among guys with lagging libido during winter.
Many men’s testosterone production tanks in the cold, dark months, dragging down sex drive along with it. Since both often bounce back in the spring, scientists suspect these seasonal dips and surges stem from varying levels of ambient light exposure.
This theory prompted a team of Italian researchers to test whether light therapy could provide that sought-after spark. This treatment, sometimes used to combat seasonal affective disorder, involves sitting close to a special light box every morning during winter. The box beams about 100 times brighter than normal indoor lighting to mimic a sunny summer day. By keeping your eyes open but not staring directly into it, the light stimulates the retina, triggering chemical changes in the brain that can get your circadian rhythm back on track and restore normal hormone production.
The researchers recruited 38 men who’d been diagnosed with either hypoactive sexual desire disorder or sexual arousal disorder — both conditions resulting in lackluster sex drive — and divided them into two groups. After measuring everyone’s testosterone levels and scoring their self-reported sexual satisfaction, half of the men used a light box for 30 minutes every morning for two weeks. The other half used a dummy light box, meaning the light wasn’t intense enough to be effective, but the guys didn’t know that, so it was a true placebo.
By the study’s end, the control group’s testosterone levels didn’t change and their reported sexual satisfaction scores barely budged. However, the light-therapy group got big-time benefits. Their testosterone levels increased by 71 percent, and their sexual satisfaction scores jumped from two (out of 10) to 6.7 — a more than threefold increase.
“Since we already know that both interest in sex and testosterone levels are usually higher in the spring and summer and believe light has something to do with this, we weren’t surprised that light therapy boosted these men's sexual desire,” says Dr. Andrea Fagiolini, lead researcher and a psychiatrist at the University of Siena School of Medicine. “The exact mechanism is not known, but we think light increases levels of luteinizing hormone, a pituitary hormone that triggers a rise in testosterone levels.” Fagiolini says light therapy may also lead to a decline in melatonin, which could also spark sexual desire.
Another perk of this treatment, says Fagiolini, is it has far fewer side effects than libido-stoking drugs. “Most people can receive light therapy without harm,” he says. “Yet there are some risks, such as becoming manic or euphoric, photo allergies for people taking certain medications, and eye problems in those with certain eye illnesses like glaucoma. Always consult a physician before starting treatment.”
Light boxes are sold on Amazon and directly from manufacturers online, but they are not approved or regulated by the Food and Drug Administration, so do your homework and purchase wisely. Ask your doctor for recommendations, and investigate whether a certain brand is used in clinics or research institutions. No matter what, make sure a box provides at least 10,000 lux, the light intensity shown to be effective for seasonal depression and now, thanks to this study, for firing up your libido.