Objectives:
Seasonal trends were demonstrated in reproduction and sexual activity. Through the secretion of meolatonin the pineal gland plays an important role, in the neuroendocrine control of sexual function and reproductive physiology. We hypothesized that inhibition of the pineal gland activity through a light treatment may favorably affect sexual function.

Methods:
We recruited 24 subjects with a diagnosis of hypoactive sexual desire disorder and / or primary sexual arousal disorder. The subjects were randomly assigned to either active light treatment (ALT) or placebo light treatment (L-PBO). Participants were assessed during the first evaluation and after 2 weeks of treatment, using the Structured Clinical Interview for Sexual Disorders DSM-IV (SCID-S) and a self-administered rating scale of the level of sexual satisfaction (1 to 10). Repeated measures ANOVA were performed to compare the two groups of patients. Post-hoc analysis was performed by Holm-Sidak test for repeated comparisons.

Results:
At baseline the two groups were comparable. After 2 weeks the group treated with Light Therapy showed a significant improvement in sexual satisfaction, about 3 times higher than the group that received placebo, while no significant improvement was observed in the group L-PBO.

Conclusions:
Our results confirm a potentially beneficial effect of Light Therapy on primary sexual dysfunction. In the future, we propose to correlate clinical findings with testosterone levels pre / post treatment.