The term medical device often elicits mental images of solid, fabricated objects such as coronary stents, replacement joints, surgical sutures or adhesive bandages. Nonetheless, the term can also refer to fluid, formulated products. Personal lubricants (PLs) are a prime example of such formulated medical devices. Not only are PLs an important accessory to the practice of medicine, they also are the cornerstone of the rapidly growing intimate health or intimacy enhancement category in the over-the-counter (OTC) consumer health care marketplace. The purpose of this article is to provide a general review of PLs and to demonstrate how polymer science is essential to enabling innovation in this unique class of medical devices.