The androgen milieu and sexual desire in women seem to be tightly linked because they both decline with age. However, we are still missing a cut-off plasma level for androgens (total testosterone, free testosterone) or androgen precursors (androstenedione, dehydroepiandrosterone (DHEA) and DHEA sulfate (DHEAS)) to diagnose androgen deficiency in clinical practice. Apart from the complex multidimensional nature of sexual desire across the reproductive lifespan, the correlation between measurements of testosterone and specific signs and symptoms has been difficult because, according to guidelines, most available assays are unreliable at baseline and under hormonal treatments. Recent data obtained with accurate methods based on mass spectrometry to measure total testosterone levels found a significant positive association with sexual desire, arousal and masturbation in midlife US women across the menopausal transition. Even in a European cohort of healthy women aged 19-65 years, sexual desire, measured with a validated questionnaire, correlated overall with free testosterone and androstenedione measured with mass spectrometry. Collectively, these data support the therapeutic use of testosterone for low desire and sexual dysfunction in those clinical conditions in which androgen deficiency may be accurately diagnosed.