L-Theanineand Mental Energy.
Evidence gradeC
ImpactSmall
Confidencemedium
Imported rating. This grade comes from SuppCo and has not been independently reviewed. It describes research, not a product, and it is not medical advice.
The rating
- Direction
- Favourable
- Rated by
- SuppCo
- Observed
- 28 September 2026
Studies behind it
Acute effects of tea constituents L-theanine, caffeine, and epigallocatechin gallate on cognitive function and mood: a systematic review and meta-analysis.D. Camfield · Nutrition reviews2014The combination of L-theanine and caffeine improves cognitive performance and increases subjective alertnessT. Giesbrecht · Nutritional Neuroscience2010L-theanine, a natural constituent in tea, and its effect on mental state.A. Nobre · Asia Pacific journal of clinical nutrition2008