- Male hormone
testosterone promotes sexual desire or libido.
- Many men with low
sexual drive show low testosterone levels.
- Blood levels of
testosterone in men shown to decline in winter months.
- Exposure to bright
light may up testosterone levels, promoting libido in men with hypoactive
Exposure to bright light
raises testosterone levels, leading to greater sexual satisfaction in men with
a low sexual desire or libido
. These were the
observations of a pilot randomized placebo-controlled trial, presented at the European
College of Neuropsychopharmacology (
ECNP) conference in Vienna.
Problems In Men
A variety of sexual
occur in men worldwide, affecting their sexual satisfaction.
These include erectile dysfunction
, problems with
, orgasmic issues and a low interest
in sex (libido).
‘Having low interest in sex? Step out into the sun or turn on the lights.’
Low sexual desire may be
present in many men over the age of 40, with studies suggesting that up to 25%
of men report problems, related to age and other factors. Scientists had
earlier noted that sexual desire also varies with the seasons, prompting the
hypothesis that levels of ambient light could influence sexual desire.
Details of The Study
A group of researchers
from the University of Siena in Italy
have studied the effects of exposure to bright light on sexual responses. They
found that routine, early morning use of a light box, similar
to those used to overcome Seasonal Affective Disorder (SAD), caused
both increased testosterone levels as well as higher reported levels of sexual
The scientists, led by
Professor Andrea Fagiolini, selected 38 men who were attending the Urology Department of
the University of Siena after being diagnosed
with hypo-active sexual desire
disorder or sexual arousal disorder
both of which are characterized by a lack of interest in sex. All men underwent an initial evaluation
to find out their baseline level of interest in sex, and testosterone levels
were also measured at the same time.
The scientists divided
the participating men into two groups, with one group receiving regular light
treatment using a specially customized light box. The control (placebo) group
was treated with a light box which had been adapted to emit significantly less
amount of light. Both groups underwent this exposure to light early in the
morning, with treatment lasting about half an hour per day. Following two weeks
of light treatment or placebo, the researchers reassessed degree of sexual
satisfaction and testosterone levels.
of The Study
It was found that levels
of sexual satisfaction were significantly more in the treatment group, as
compared to the placebo group.
Professor Fagiolini said,
"We found fairly significant differences
between those who received the active light treatment, and the controls. Before
treatment, both groups averaged a sexual satisfaction score of around 2 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 3-fold increase on the scale we used
. In contrast, the
control group only showed an average score of around 2.7 after treatment".
testosterone levels showed an increase in men who had been given active light
treatment. The average testosterone levels of the control group, however,
showed no major change during the course of the treatment. Levels were around
2.3 ng/ml at both the starting and the end of the study. On the other hand, the
group that was administered active treatment displayed an increase in
testosterone levels from around 2.1 ng/ml in the beginning to 3.6 ng/ml after
Professor Fagiolini further elaborated,
"The increased levels of testosterone explain the
greater reported sexual satisfaction. 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".
Testosterone And Sexual Desire - How
Light Therapy May Help
The male sex hormone testosterone is known to
increase sexual desire, though scientists are yet to figure out how. Low levels
of testosterone are not the only reason for a low sexual drive, though many men
with low sexual drive show low testosterone levels. Other causes of a
decreased sexual interest include stress, lack of sleep, depression and chronic
underlying medical disorders.
Fagiolini explains how light therapy may increase testosterone levels and promote
believe that there may be several explanations to explain the underlying
mechanism. For instance, light therapy
inhibits the pineal gland in the center 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. Even at that stage,
there will be a few patients - for example those with an eye condition or
anyone taking medicines (antidepressants or antibiotics) which affect
light sensitivity - who would need to take special care. 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
Available Treatment Options For Low Sexual Drive
researchers observe that several possible reasons may exist for lack of sexual
drive, and treatment depends on the underlying cause. However, currently
available therapeutic options include
injections, antidepressants, and other medications
researchers believe that light therapy could provide similar benefits as
medications, but with far lesser side effects.
the role of light therapy in improving hypo-active sexual desire is established, it may
signify new treatment hope for men with decreased libido, without the side
effects of medications.
Eduard Vieta (Chair of the Department of Psychiatry and Psychology at the
University of Barcelona Hospital Clinic and treasurer of the ECNP) remarked "Light
therapy has been used successfully in the past to treat some forms of
depression and this study suggests now that it may also work to treat low
sexual desire in men. The mechanism of action appears to be related to the
increase of testosterone levels. Before this kind of treatment, which is likely
to be better tolerated than pharmacological therapy, gets ready for its routine
use, there are many steps to be implemented, including replication of the
results in a larger, independent study, and verifying whether the results are
long-lasting and not just short-term". References:
- Konstantinos Hatzimouratidis, MD; Epidemiology of Male Sexual Dysfunction; American Journal of Men's Health