Photopharmacology is a rapidly growing field that employs light to control the biological activity of drugs with high spatiotemporal precision. It is based on molecules that change their structure upon irradiation, either reversibly (cages) or irreversibly (photoswitches). In the last decade, many light-activable bioactive compounds have been reported. In vitro, photoswitches have been developed for ion channels, such as enzyme inhibitors, receptor agonists and antagonists, anticancer, and antibiotics. In vivo reported examples have been used to restore light sensitivity in blind mice and reduce chronic pain. The illumination setup and light conditions used for these experiments can be critical. A current challenge is that different researchers are using other illumination devices and protocols, and sometimes it can be challenging to reproduce experiments between laboratories. This Methods Collection aims to facilitate sharing protocols and techniques used for in vitro and in vivo assays with light-activable molecules.