When skin cells responsible for pigmentation are exposed to estrogen or progesterone, the cells respond by adjusting their melanin production, resulting in either skin darkening or lightening. Although pregnant women often experience alterations in skin pigmentation, the reason for the changes has long puzzled researchers.  Now, a study from researchers at the University of Pennsylvania, has identified cellular pathways in skin pigment cells that are … Continue reading Study identifies previously unknown pathways that control skin tanning and lightening.