Deep Work Focus

L-theanine on its own is mildly relaxing. Combined with caffeine, it produces a documented synergistic improvement in attention-switching, accuracy on demanding cognitive tasks, and subjective alertness — while reducing the anxiety and blood-pressure spike caffeine causes alone. Most acute cognitive trials use a ratio of ~2:1 L-theanine to caffeine (e.g. 200 mg L-theanine with 100 mg caffeine, roughly one strong cup of coffee).^{[1, 2, 3]}

DHA is a structural component of neuronal membranes and EPA modulates neuroinflammation. Trial evidence shows modest improvements in working memory and reaction time in healthy young adults after sustained supplementation. The effect is gradual — 8-12 weeks to plateau. Fish oil is the most studied source; algae oil is the vegetarian alternative. Choose a product that reports EPA+DHA content explicitly, not just total fish oil milligrams.^{[4, 5, 6]}

Creatine is best known for muscular performance but has accumulating evidence for cognitive benefit — particularly in working memory and processing speed under high cognitive load or sleep deprivation. A systematic review of trials in healthy adults found small but consistent improvements in short-term memory and reasoning. Effect builds over 2-4 weeks as muscle and brain creatine stores saturate. Monohydrate is the only form with substantive trial evidence; the more expensive forms have no demonstrated benefit.^{[7, 8, 9]}