The Cognitive and Mood-Enhancing Effects of Guayusa Extract: A Systematic Review of Randomized Controlled Trials

Abstract Background : Guayusa (Ilex guayusa) is a traditional Amazonian plant known for its stimulant and mood-enhancing effects. Recently, it has been commercialized as Ama Tea Max, promoted for boosting cognition and mood. Objectives : This systematic review aimed to evaluate the impact of AmaTea® Max on cognitive performance and mood regulation in healthy adults. Method : A comprehensive search was conducted in Google Scholar, PubMed, Scopus, and ScienceDirect. Four studies were eligible for inclusion because they investigated Guayusa or AmaTea® Max in healthy adults using randomized, double-blind, placebo-controlled designs. Outcomes assessed across the studies included cognitive performance, mood, physiological markers (e.g., heart rate, blood pressure), and gaming performance. Results: The Guayusa-based product AmaTea® Max was well tolerated, with no negative effects reported. Various dosages and formulations were examined across studies. Almost all trials reported improvements in cognitive functions such as attention, reaction time, and dual-task performance, particularly under mentally demanding tasks like gaming or multitasking. Mood changes were more variable, with some evidence of reduced fatigue, mental tension, and improved subjective alertness. However, differences in outcome measuring and assessment tools limited direct comparisons across studies. Conclusion: The Ilex guayusa extract used in AmaTea® Max appears to be safe and may offer modest acute benefits for cognition and mood in healthy adults. Further research is needed to determine long-term effects and optimal dosing.