From tradition to the clinic
Guayusa has been consumed by Kichwa communities in the Ecuadorian Amazon for generations, but only recently has it entered controlled clinical study. A randomized, placebo-controlled trial published in Nutrients in 2022 examined a standardized guayusa extract and offers the clearest human data to date on the leaf’s effect on attention and mood.
What the trial measured
The study used a commercial guayusa extract (marketed as AmaTea® Max) and recruited habitual gamers — a population that places sustained demands on attention and reaction time. Participants completed cognitive tasks and mood assessments after taking either the extract or a placebo, allowing researchers to isolate the ingredient’s acute effects.
The findings
Compared with placebo, the guayusa extract was associated with improvements in measures of attention and aspects of mood, without the jittery side effects often reported with higher-dose stimulants. In other words, participants showed sharper task performance alongside a favorable subjective state — a result consistent with the caffeine and L-theanine profile discussed elsewhere in this hub.
Reading the evidence carefully
One well-designed trial is a meaningful data point, not a final verdict. The study examined a specific standardized extract at a specific dose in a defined population, and further research is needed to generalize across formats and users. It is best understood as promising early human evidence rather than proof of a fixed benefit.
Implications for nootropics and functional drinks
For developers of cognitive and functional products, the trial gives guayusa something many botanicals lack: a peer-reviewed human study pointing in a favorable direction. That supports its use as a differentiated, naturally derived active in nootropic blends, focus beverages and energy products where clean cognitive support is the goal. In a category crowded with unstudied ingredients and bold marketing, a published randomized trial is also a meaningful due-diligence asset for buyers who need evidence before they commit to a formulation.
This article is for informational purposes only. These statements have not been evaluated by the FDA.