Assessing the Impact of High Theacrine Doses on Hemodynamic Measures, Cognitive Performance, and Physiological Stress

Preliminary evidence indicates that theacrine, a naturally occurring stimulant, improves feelings of energy without impacting heart rate, blood pressure, or cognitive performance after consumption. The limited effects of theacrine consumption on blood pressure, heart rate, and cognitive performance could be due to the low doses (e.g., 200 mg) used in previous studies. Therefore, the purpose of this study was to investigate the effect of theacrine doses greater than those previously tested on heart rate, blood pressure, subjective feelings of energy, and cognitive performance. This is also the first study to investigate the impact of a theacrine-exclusive supplement on salivary cortisol and alpha-amylase. Nineteen healthy men (n=5) and women (n=14) who were habitual caffeine consumers completed this randomized, double-blind, crossover-design study. Participants completed a baseline visit and four experimental visits, with a 7-day washout period. They were randomly assigned one of four treatments each visit: placebo, 3 mg/kg theacrine, 6 mg/kg theacrine, or 9 mg/kg theacrine. Measurements were completed pretreatment and at 60, 90, 120, 150, and 180 minutes post-treatment. Repeated measures ANOVA results indicated greater salivary cortisol concentration in the theacrine conditions versus the placebo condition at 120 and 180 minutes post-treatment. The effect of greater theacrine doses on subjective feelings of energy is unclear, as energy only improved in the placebo treatment. Overall, greater theacrine doses increased salivary cortisol with no significant impacts on heart rate, blood pressure, subjective feelings of energy, alpha-amylase, and cognitive performance.