The late stage functionalization (LSF) of complex biorelevant chemicals is a valuable approach for accelerating the discovery of structure–activity relationships (SARs) and optimising ADME (absorption, distribution, metabolism, and excretion) profiles. To this end, visible-light metallaphotocatalysis provides a unique opportunity to develop smooth and clean drug functionalization by realising site-specific reactivities under very mild reaction conditions. This study provides a comprehensive evaluation of the current research, highlighting recent advances in the discipline while emphasising predicted future advancements and prospective applications along with visible-light metallaphotocatalytic synthesis methods for the LSF of medicines and pharmaceutically potent compounds that are now accessible.