Supplement Monograph
L-Theanine
A calming amino acid from tea that takes the edge off caffeine without sedation.
Where Does It Come From? (3)
What is L-Theanine?
L-theanine is an amino acid found almost exclusively in the tea plant (Camellia sinensis). It is the compound most responsible for the smooth, alert calm that tea produces — distinct from the jittery stimulation of coffee, despite both containing caffeine.
What it’s used for
L-theanine is taken to promote a state of relaxed alertness, reduce situational anxiety, and soften the side effects of caffeine such as jitteriness and the post-caffeine crash. It is one of the most popular and well-tolerated nootropics, and is frequently paired with caffeine in a roughly 2:1 ratio (theanine to caffeine).
How it works
L-theanine readily crosses the blood–brain barrier and increases the brain’s production of alpha waves, an electrical pattern associated with calm, wakeful focus. It also modulates the balance of the excitatory neurotransmitter glutamate and the calming neurotransmitter GABA, and can raise levels of dopamine and serotonin.
Dosage
A typical dose is 100–400 mg. When stacked with caffeine, 200 mg theanine with 100 mg caffeine is a common starting point.
Safety
L-theanine is very well tolerated, with no serious adverse effects reported at normal doses. As with any supplement, those who are pregnant, breastfeeding, or on medication should consult a qualified practitioner first.