L-Theanine for Sleep
L-theanine is an amino acid found naturally in tea. Research has examined relaxation and subjective sleep outcomes, but that does not establish efficacy for any finished multi-ingredient product.
What to look for on a label
Check the exact amount per serving, serving size, other active ingredients and directions. When an ingredient sits inside a proprietary blend, you may not know its individual amount.
What the evidence can tell us
Ingredient studies can help frame plausible uses and uncertainties, but study populations, doses and formulations differ. They should not be treated as proof that a multi-ingredient commercial formula will deliver the same result.
How this relates to Yu Sleep
L-Theanine is part of the current Yu Sleep formula information. For a product-level decision, read the full formula and safety context rather than evaluating one ingredient in isolation.
Sources
- Yu Sleep ingredient information — manufacturer/offer-site claims; verify against the bottle label.
- NCCIH: Melatonin — What You Need to Know — government health information.
- PubMed: L-theanine systematic review/meta-analysis (2025) — ingredient-level research.