Currently, IoT systems are becoming widespread in the healthcare system. Today’s e-Health systems have advanced functional capabilities. They can control the indoor microclimate, determine geolocation parameters, interact with a person via a Web interface. However, the ability to adapt to human physiological parameters remains a complex issue that requires a deep understanding of a particular person’s physiological processes and the physical processes occurring in the IoT system. This study presents an approach to intelligent adaptive lighting system development based on research in the fields of electronic engineering, computer science, e-health, a person’s physiology. Taking into account the various light sources that influence the system using human circadian rhythms can adapt lighting to the physiological needs of a person, preventing disruption of their circadian rhythms, and therefore, deterioration in the sleeping quality, drowsiness, fatigue, low productivity, a person’s mood deterioration. Adaptation of lighting to human circadian rhythms is performed taking into account both physiological data and the room microclimate parameters where the person is located. To implement the proposed approach to an intelligent adaptive lighting system development based on human circadian rhythms, a device circuit for circadian rhythms determination and control was proposed, which was tested in laboratory conditions, and the functionality of the IoT system was simulated in Matlab. The practical implementation of the developed IoT adaptive lighting system in the practical projects showed an increase in the comfort of people’s stay in the room, as well as an increase in the energy efficiency of the lighting system by 11%.