Macrolane™, a compound composed of hyaluronic acid, is the newest product to be marketed for breast augmentation. Like many previous breast augmentation products, Macrolane has been authorised for use with very little published scientific data on its safety and efficacy in breast augmentation. This article reviews the evidence available on the safety of using hyaluronic acid and raises concerns with regard to its use as a product for breast augmentation, the technique recommended for its use, and the authorisation process for new implantable medical devices. It is strongly recommended that clinicians review the lack of data on Macrolane before offering it as a treatment option to patients.