Considerations before choosing (extemporaneously) compounded products.

Despite a plethora of pre-packaged topical products produced by the pharmaceutical industry for treating skin diseases, the practice of extemporaneous compounding continues, albeit at a low level (<1% of prescriptions). Sourcing prescription compounding services via the Internet has increased dramatically in recent years, posing new risks to patients and prescribing physicians. The technical, economic, and medico-legal issues associated with the practice of ad hoc compounding are reviewed and updated. A practical set of recommendations are provided for prescribing physicians and their recipient patients with the hope that, if followed, they will reduce the potential risks associated with the use of products that are formulated extemporaneously.