The One Ingredient A Neurohacker Adds To Coffee To Boost Its Brain Benefits

In a world of trendy nootropics, Ricker tells mbg she recommends adding one simple ingredient to your coffee: L-theanine. A neurologically active amino acid, L-theanine is a time-tested component of the green tea plant (and white and black tea—but green tea has the most of it).

In one small study published in the journal Nutritional Neuroscience, a combination of caffeine and L-theanine1 did, indeed, improve participants' mental performance.

In the study, 27 people were given 50 milligrams of caffeine, either with or without 100 milligrams of L-theanine, and thereafter, their cognition and mood were analyzed (including factors like word recognition, visual processing, attention switching, and more).

After 60 minutes of having the caffeine and L-theanine, participants saw improved speed and accuracy of performance in the attention-switching task compared to the placebo. They were also less easily distracted at both 60 minutes and 90 minutes.

"These results replicate previous evidence which suggests that L-theanine and caffeine in combination are beneficial for improving performance on cognitively demanding tasks," the study authors write.

Bonus: This powerhouse amino acid has other research-backed benefits like helping to ease stress2 and slowing cognitive decline3, too.