Amino acid from tea leaves studied for promoting relaxation without sedation.
Quick answer: This ingredient has moderate evidence — some solid clinical support, though results aren't fully consistent across studies. Amino acid from tea leaves studied for promoting relaxation without sedation.
L-Theanine is most commonly studied and used for sleep. Amino acid from tea leaves studied for promoting relaxation without sedation. The strength of evidence behind it is currently classified as moderate — this ingredient has moderate evidence — some solid clinical support, though results aren't fully consistent across studies.
Here's where L-Theanine shows up in our current formulas:
In the Sleep category, L-Theanine is often formulated alongside other ingredients that target the same goal through different mechanisms — which is why you'll frequently see it in a blend rather than sold alone:
Combining ingredients with different, complementary mechanisms is generally more useful than taking several ingredients that all do the same thing — it's worth checking a product's full ingredient list rather than judging it on one "hero" ingredient alone.
As with any supplement ingredient, individual response varies, and it's worth checking with a healthcare provider before starting L-Theanine if you're pregnant, nursing, taking medication, or managing a health condition. For a full breakdown of dosage and side effects, see the related health goal guide below.
At studied doses, most people tolerate it well, though it's always worth checking with a healthcare provider, especially if combined with other supplements or medication.
We classify evidence as Strong, Moderate, or Limited based on the quantity, size, and consistency of clinical research specifically studying this ingredient for this use. See our Editorial Policy for details.
Yes — standalone versions are usually available. A blend simply combines it with complementary ingredients for convenience and broader coverage of the same health goal.