Given the recent National Institutes of Health proposal for balanced use of male and female cells and animals in preclinical studies, we explored whether sex bias exists in skin research. We surveyed 802 dermatological research articles from 2012 through 2013. No information about the sex of studied cells or animals was provided in 60% of papers. Among keratinocytes of known sex, 70% were male. Few studies compared male versus female cells or animals. Disclosure of sex and comparative studies contribute to our understanding of the biologic basis of sex differences. Addressing sex-speci fi c differences in preclinical research informs subsequent clinical trial design and promotes individualized therapy.