About Ilex Guayusa
Caffeine-containing holly leaf from the Amazon (relative of yerba mate). Used in energy/tea blends; provides caffeine and polyphenols, but standalone human RCTs on guayusa itself (separate from its caffeine content) are essentially absent.
What Ilex Guayusa supports
- Provides caffeine and antioxidants — benefits mirror caffeine content; no guayusa-specific RCTs
Clinical evidence
Limited clinical evidence. No dedicated human RCTs isolating guayusa's effects from its caffeine content.
NIH Fact Sheet