In recent years, sulfoximines have received significant attention in both academia and industry. This development has been reinforced by the introduction of new methods for preparing and efficiently accessing key sulfur-based reagents allowing further functionalisations. For all fields and in particular those related to pharmaceutical and agrochemical applications, the knowledge of potential degradation pathways of sulfoximines is vital. Being aware of possible metabolites minimises the risks of late stage failures. In this review, we describe chemical transformations in the laboratory leading to sulfoximine degradations. Those include reductive and oxidative pathways as well as C–S bond cleavage reactions. In a wide frame the intention of this summary is to provide a better understanding of decomposition-like reactions of sulfoximines thereby enabling a more focussed search and analysis of byproducts and potential metabolites in biorelevant systems.