The following are representative papers of the effects, and effect sizes of the ingredients in SPRINT, RISE, and YAWN with the greatest efficacies.
90 Minutes after ingestion of 250 mg L-theanine and 150 mg of caffeine, the combination showed:
9.27% decrease in simple reaction time compared to placebo (no effect of caffeine-alone in this paradigm);
13.94% increase in a sustained attention task compared to placebo (caffeine saw 16.62% increase in this paradigm);
19.48% increase in self-reported alertness (caffeine had non-significant 14.96% increase in this paradigm);
3.43% increase in a semantic memory task (no effect of caffeine in this paradigm).1
Figure 1. Psychological Effects of placebo, caffeine, L-theanine, and caffeine + L-theanine. For caffeine and theanine, statistically significant improvements in simple reaction time, rapid visual information processing (RVIP), numeric memory reaction time, sentence verification accuracy, and word recognition reaction time were observed.
12 weeks after ingestion of 300 mg of Bacopa monnieri every day showed:
12.28% increase in learning rate compared to placebo;
50% reduction in forgetting rate compared to placebo;
17.67% reduction in “inspection time” compared to placebo (a measure of how quickly relevant information was identified in a task);
33.3% reduction in state anxiety.2
4.5 mg of salidroside Rhodiola rosea extract was given to group of 19-21 year old cadets at 4:00 am, after a shift of night-duty work. Treatment with the extract resulted in:
In a meta-analysis of the effect of melatonin on sleep:
sleep latency is reduced by 7.06 minutes (fall asleep an average of 7.06 minutes faster);
sleep time is increased by 8.25 minutes;
sleep quality is increased by 0.22 standardized mean units (based on the distribution of responses from a sleep quality self-report questionnaire).4
In a cohort of sleep deprived people (forced to sleep 25% less than usual for three nights in a row), treatment with 3 g of glycine the night before showed
Haskell, C. F., Kennedy, D. O., Milne, A. L., Wesnes, K. A., & Scholey, A. B. (2008). The effects of L-theanine, caffeine and their combination on cognition and mood. Biol Psychol, 77(2), 113-122. doi:10.1016/j.biopsycho.2007.09.008
Kongkeaw, C., Dilokthornsakul, P., Thanarangsarit, P., Limpeanchob, N., & Norman Scholfield, C. (2014). Meta-analysis of randomized controlled trials on cognitive effects of Bacopa monnieri extract. J Ethnopharmacol, 151(1), 528-535. doi:10.1016/j.jep.2013.11.008
Shevtsov, V. A., Zholus, B. I., Shervarly, V. I., Vol'skij, V. B., Korovin, Y. P., Khristich, M. P., ... & Wikman, G. (2003). A randomized trial of two different doses of a SHR-5 Rhodiola rosea extract versus placebo and control of capacity for mental work. Phytomedicine, 10(2), 95-105.
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