E-cigarettes and erectile dysfunction: biological mechanisms and research challenges.

Electronic cigarettes are widely promoted as harm-reduction alternatives to conventional tobacco smoking, yet their potential effects on male sexual health remain incompletely characterised. Erectile dysfunction is a predominantly vascular condition with important neuroendocrine regulation and is highly sensitive to endothelial injury, oxidative stress, hormonal imbalance, and autonomic dysregulation, all of which may plausibly be influenced by electronic cigarette use. Despite increasing global prevalence, direct evidence linking electronic cigarette use to erectile dysfunction remains limited. This narrative review synthesises current experimental, clinical, and epidemiological evidence examining the association between electronic cigarette use and erectile dysfunction, with emphasis on underlying biological mechanisms and key research gaps. Emerging evidence implicates endothelial dysfunction, impaired nitric oxide bioavailability, oxidative stress, inflammation, hormonal disturbance, autonomic imbalance, sleep disturbance, and exposure to aerosolised substances and metals as interconnected pathways that may contribute to erectile dysfunction. Overall, the existing literature remains preliminary and largely hypothesis-generating, with no longitudinal studies capable of establishing causality or dose-response relationships. Well-designed prospective studies are required to clarify the long-term sexual health outcomes associated with electronic cigarette use.