Certain serums designed to promote eyelash growth contain prostaglandin derivatives, pharmacologically active substances that were originally used in ophthalmology to treat glaucoma. Their effectiveness in stimulating eyelash growth is well established, but several ocular adverse effects have also been reported. In response to concerns raised about their use in cosmetics, European health and scientific authorities have examined their safety. What do current regulatory assessments say about these ingredients? Let’s take a closer look.