A large amount of stress in life and the progress of technology, and in particular the ability to use light at any time of the day often results in disturbances of the circadian rhythm. This is manifested by problems with falling asleep, inability to achieve satisfaction from sleep, lack of energy in the morning. As reported by scientists, regularly taking PQQ can be helpful when we want to improve our daily rhythm. 
17 people underwent a study to check the effectiveness of the PQQ supplement for parameters such as fatigue, stress, quality of life and sleep efficiency. The effects were determined by comparing the results of the relevant questionnaires and the results of testing saliva samples taken immediately after waking up and 30 minutes later, to check the level of cortisol. The trial lasted 8 weeks.
The results showed an improvement in practically all parameters tested, i.e. in perceived satisfaction with life at various levels, energy level and fatigue and noticeable stress. There was also an improvement in the aspects related to sleep, i.e. in the speed of falling asleep, length of sleep, or well-being after waking up, but some of these parameters had to be delayed until the 8th week. Most of the parameters improved already in the middle of the experiment, but at the end the results were much more pronounced. These results have been confirmed in physiological studies by finding an improvement in cortisol response after waking up, suggesting a more efficient and restorative sleep.
The results of this study indicate that PQQ is an interesting tool for people who want to improve the overall quality of life and normalize sleep disorders, with regular supplementation recommended for at least 8 weeks for the results to be truly satisfying.
