Assessing The Impact Of High Theacrine Doses On Hemodynamic Measures And Subjective Feelings Of Energy

Theacrine (TCR) is a natural supplement that exhibits stimulant properties. Preliminary evidence shows improved feelings of energy with no increase in heart rate (HR), systolic blood pressure (SBP), and diastolic blood pressure (DBP) after consumption. PURPOSE: To investigate the effect of higher doses of TCR relative to body weight on hemodynamic measures and subjective feelings of energy. METHODS: 19 normotensive men and women (20.7 ± 2.1 years; BMI: 26.0 ± 4.2 kg/m2) who were habitual caffeine consumers completed this randomized, double-blind, crossover design study. Participants completed a baseline visit followed by four experimental visits with at least a 7-day washout between visits. Participants were randomly assigned one of four treatments during each experimental visit: Placebo (PLA), 3 mg/kg TCR, 6 mg/kg TCR, or 9 mg/kg TCR. Resting brachial HR, SBP, and DBP were assessed. Feelings of energy, alertness, and mood were assessed via a visual analog scale. Measurements were completed pre-treatment, then 60, 90, 120, 150, and 180 minutes post-treatment. RESULTS: Repeated measures ANOVA revealed no significant condition x time effects for HR, SBP, and DBP. There was a significant condition effect for DBP (p = 0.003) with the 3 mg/kg TCR (1.8 ± 3.8 mmHg), 6 mg/kg TCR (2.8 ± 3.8 mmHg), and 9 mg/kg TCR (3.9 ± 4.3 mmHg) doses all increasing DBP compared to the PLA (p ≤ 0.001). There was also a significant time effect for HR (p ≤ 0.001) and DBP (p ≤ 0.001). After TCR consumption, HR was significantly lower at 60 minutes (-8.3 ± 3.5 bpm; p ≤ 0.001) and 90 minutes (-9.6 ± 3.2 bpm; p = 0.048) post-treatment and remained lower over the rest of the time points compared to pre-treatment. DBP increased across all time points, from 66.3 ± 7.4 mmHg pre-treatment to a peak of 70.8 ± 6.6 mmHg at 180 minutes post-treatment. There were significant condition x time effects for energy (p ≤ 0.001) and focus (p = 0.025), with these feelings increasing post-treatment of PLA. CONCLUSIONS: TCR supplementation at increasing doses relative to body weight did not impact SBP and HR while moderately increasing DBP. The effects of TCR supplementation on subjective feelings of energy and focus are unclear as these measures increased only after PLA and remained stable after TCR consumption.