Guayusa
An Amazonian holly leaf brewed as a caffeinated tea. Two small acute trials show the alertness effects you would expect from caffeine; the claim of a distinctively 'smoother' energy is not established.
Evidence last reviewed: August 2026
What the science says
- Acute mood and cognitive performance Limited evidence
A randomized dose-response trial of guayusa leaf extract in healthy adults found acute changes in mood and motor-cognitive performance along with the expected small cardiovascular effects. Effects were modest and the study tested a single session, not repeated use.
- Compared with other stimulant extracts Limited evidence
A randomized trial comparing acute guayusa tea and a lion's mane extract on cognitive performance in healthy adults reported small, task-specific effects. The design cannot separate guayusa's contribution from its caffeine content.
- Safety and composition Limited evidence
A critical review of guayusa's composition and history of use concluded that it is a caffeine-containing stimulant with an antioxidant profile similar to other Ilex species such as yerba mate, and that its safety record comes from traditional consumption rather than from trials.
Dosage & safety
Scientific references
- Acute, dose-response effects of guayusa leaf extract on mood, cognitive and motor-cognitive performance, and blood pressure, heart rate, and ventricular repolarization
- Acute Effects of Naturally Occurring Guayusa Tea and Nordic Lion's Mane Extracts on Cognitive Performance
- A critical review of the composition and history of safe use of guayusa: a stimulant and antioxidant novel food
Where to buy
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