This study aims to explore the potential of the Electrophotonic Emission Analysis (EPEA) method as an instrumental approach for studying stress in biomedical research. Specifically, the study focuses on assessing the stress levels of Ukrainian military personnel returning from the front using the EPEA method. Materials and methods: A total of 96 individuals participated in this open, non-randomized, exploratory, non-controlled, comparative study. Among them, 26 were military personnel, while the rest belonged to the comparison groups. The EPEA analysis was conducted using a certified hardware and software measuring device called Bio-Well 2.0 (United States). Results: The study found a significant decrease (p<0.0001) in energy levels, with both the military personnel group (41±4.25 J) and the functionally healthy individuals group (57.38±20.78 J) showing similar results. Among the participants, 62% of military personnel and 95% of patients with non-communicable diseases demonstrated optimal energy levels, while 38% and 5% respectively showed reductions. The stress levels measured were 3.69±0.62 cu for military personnel, 3.69±0.62 cu for functionally healthy individuals, and 3.99±1.17 cu for patients with non-communicable diseases. Conclusions: The EPEA method proved effective in instrumentally detecting increased levels of stress and anxiety in 96% of military personnel, 93% of functionally healthy individuals, and 87% of patients with non-communicable diseases in the study. It is of fundamental importance for scientific and systemic medicine to establish that changes in biophoton emission can be observed in patients with non-communicable diseases, including military personnel. Significant differences in total energy levels were found between patients and functionally healthy individuals, with EPEA results showing 41±4.25 J and 43.86±4.87 J respectively for patients and functionally healthy people (p<0.0001). Electro-photonic emission analysis is a promising, valid, accessible instrumental method for biomedical research.