This study aimed to demonstrate the effect of enhanced amino acid compositions with cold plasma on human psychological stress by using blood tests, biofeedback, and gas discharge visualisation (GDV) techniques for stress measurements. An open, randomised, placebo-controlled trial for 30 days was conducted. 70 healthy people aged 35-65, men and women, were measured initially, randomly divided into three groups (experimental, control, and placebo), and measured 30 days later for changes in stress levels. Twenty people used amino acid composition; 30 used the same amino acid composition processed with cold plasma radiation, while 20 used a placebo. The ethics committee of the Federal State Budget Institution "Saint-Petersburg Scientific-Research Institute for Physical Culture," St. Petersburg, Russia, approved the study protocol. All participants signed an informed consent form, where a written and oral explanation of the research protocol was provided. Blood, biofeedback, and GDV test results were presented to show differences in stress levels during the experiment. After 30 days, results for experimental and control groups were presented. Amino acids processed by the radiation of a cold plasma – enhanced with Igniton particles - had the most significant effect on stress levels. The results suggested that enhanced amino acid compositions significantly affected human stress levels during the longitude period. Stress reduction in humans can significantly influence disease prevention and health maintenance, ultimately extending human life expectancy.