The Role of Enzymes in Female Sexual Function: Molecular Pathways Linking Hormones, Neurotransmitters, and Sexual Health

Abstract Female sexual function is regulated by a sophisticated network of hormonal, neurological, and vascular mechanisms, in which enzymes play a pivotal yet often overlooked role. Beyond their established functions in metabolism, specific enzymes act as modulators of hormone biosynthesis, neurotransmitter turnover, and local vascular responses, thereby shaping desire, arousal, and orgasm. Aromatase, the enzyme responsible for estrogen synthesis, directly influences libido, vaginal lubrication, and reproductive health. Oxytocinase regulates the availability of oxytocin, a neuropeptide essential for intimacy, bonding, and orgasmic release. Monoamine oxidase (MAO) governs dopamine and serotonin degradation, thereby modulating mood, reward, and sexual desire. Similarly, nitric oxide synthase (NOS) produces nitric oxide, a critical mediator of vasodilation that facilitates clitoral engorgement and vaginal lubrication. Phosphodiesterases (particularly PDE 5) regulate cyclic GMP signaling, directly influencing genital blood flow and arousal physiology. Dysregulation of these enzymatic pathways has been implicated in hypoactive sexual desire disorder, female sexual arousal disorder, anorgasmia, and comorbid depressive states. Understanding these mechanisms provides insight into why certain women respond to pharmacological agents such as PDE-5 inhibitors or MAO inhibitors, while others show limited benefit. Furthermore, enzyme mediated pathways highlight potential therapeutic targets for personalized interventions, including enzyme modulators, hormone-enzyme interactions, and lifestyle modifications that influence enzymatic activity. Despite the significance of these mechanisms, current clinical practice often focuses primarily on hormonal or psychological explanations, overlooking enzymatic regulation. Recognizing enzymes as integral determinants of female sexual function not only expands the scientific understanding of sexuality but also offers opportunities for innovative therapeutic approaches. This review highlights the central role of enzymes as molecular mediators linking hormonal balance, neurotransmitter activity, and sexual health in women.