Clinical Trials

Multiple clinical trials have evaluated L-theanine formulations and dietary supplements to investigate their therapeutic effects on stress and psychological stress in adults. Encompassing Phase 2 testing as well as trials designated as Not Applicable in phase classification, all of these studies have reached completed recruitment status. These evaluations were conducted by both academic institutions and industry sponsors, including Ethical Naturals Inc., KGK Science Inc., and University Hospital Clermont-Ferrand.

NCT Number Recruitment Conditions Sponsor/Collaborators Start Date Phases
NCT05808595 Completed
Stress
Ethical Naturals Inc.|KGK Science Inc.
 2023-04-04 Phase 2
NCT04391452 Completed
Stress Psychological
University Hospital Clermont-Ferrand
 2020-07-01 Not Applicable

(data from https://clinicaltrials.gov, updated on 2024-05-22)

Check the L-Theanine product page for in-depth specifications, including solubility, stock solutions, MOA, and working concentrations.

Compliance for Clinical Use

Mechanism and Biochemical Profile

L-Theanine functions as a glutamate analogue that crosses the blood-brain barrier to competitively bind central glutamate receptors and inhibit excitatory downstream neurotransmitter signaling. This attenuates neuronal hyperexcitation to facilitate central neural relaxation, providing a physiological basis for mitigating psychological stress in clinical evaluations.

Appendix RUO and cGMP Quality Standards

Quality Dimension RUO (Research Use Only) cGMP (Current Good Manufacturing Practice)
Clinical Applicability Prohibited in human clinical trials or medical diagnostics. Mandatory for human clinical trials (Phase I–III) and therapies.
Regulatory Status Non-regulated grade; exempt from drug manufacturing laws. Legally enforced by health authorities (e.g., FDA, EMA, NMPA).
Facility Environment Unclassified analytical or research laboratories. Validated Cleanrooms (ISO Class 5–8) with continuous monitoring.
Quality Control Basic purity and activity testing. Rigorous safety release testing (Sterility, Endotoxin, Mycoplasma).
Process Validation Basic equipment calibration; no process validation required. Full qualification (IQ/OQ/PQ) and complete batch records.
Quality Assurance Vendor self-declared without required formal QMS. Mandatory QA/QC unit, Change Control, CAPA, and vendor audits.
Regulatory Impact High risk of IND rejection if used as a critical raw material. Required for IND/NDA filings, supported by Drug Master Files (DMF).

Footnotes

Regulatory Note: Governed by FDA (21 CFR Parts 210/211/312), EMA (EudraLex Vol 4), ICH Guidelines (E6/Q7/Q9/Q10), and compendial standards (USP <71>/<85>/<1043>).

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Note: Technical data last updated: Sep 1, 2026.