L-theanine is an amino acid naturally present in tea leaves, significantly inexperienced tea. It will probably cross the blood–mind barrier, the place it gently influences neurotransmitters and brainwave exercise linked to rest and focus. If you happen to’ve ever seen that calm, centred feeling after a cup of inexperienced tea, that’s the L-theanine quietly doing its job.(5)
Mechanisms & Results:
L-theanine is thought for selling a state of relaxed alertness, usually linked to elevated alpha brainwave exercise, the identical sample related to calm focus and decreased mind-wandering. (6)
It additionally seems to affect key neurotransmitters comparable to GABA, serotonin, and dopamine, which assist regulate temper, stress, and total psychological steadiness. (7)
Essentially the most sensible profit, although, is the way it works with caffeine. L-theanine helps take the sting off caffeine’s extra intense unwanted side effects, assume nervousness, overstimulation, or that mid-afternoon crash, whereas nonetheless maintaining the psychological readability and focus that caffeine offers. It’s the rationale this pairing feels clean and regular somewhat than spiky and short-lived.
Analysis Proof
Scientific analysis backs up what many tea drinkers and nootropic customers have already seen: L-theanine and caffeine work higher collectively than both alone.
In a randomised managed trial, a mixture of round 97mg of L-theanine and 40mg of caffeine improved attention-switching velocity, accuracy, and resistance to distraction in contrast with caffeine or placebo on their very own. (8)
Systematic evaluations additionally discovered that the L-theanine–caffeine pairing persistently enhances focus, response accuracy, and application, whereas additionally lowering jitteriness and nervousness that caffeine may cause by itself. (9)
Some research even counsel that L-theanine could assist reasonable caffeine-induced will increase in coronary heart charge and blood strain, serving to clarify why the 2 collectively really feel calmer, cleaner, and extra sustainable than caffeine alone.
Limitations & Gaps
In wholesome adults, the standalone results of L-theanine are usually refined however noticeable, extra of a mild psychological smoothness than a dramatic shift in focus or temper.
A lot of the out there analysis has used managed doses, usually round 50–100mg of caffeine paired with L-theanine, and the consistency throughout research means that this mixture reliably promotes calm, centered power with out overstimulation.
L-theanine shouldn’t be going to present you Zen-like peace and focus, but it surely’s nice in case you usually expertise caffeine nervousness or crashes as it could assist to ‘clean out’ the expertise.
