This document provides an overview of antimicrobial preservation. It discusses the cell structure of microorganisms and how preservatives work to prevent their growth. Common preservatives used in ingestible and topical products are parabens, sorbic acid, benzoic acid, and sodium metabisulfite. Parabens are popular but can partition disproportionately into the oil phase of emulsions, reducing their effectiveness. Chelating agents and certain ingredients can enhance preservative efficacy while others may hinder it. Proper manufacturing and packaging are also important to consider.