L-theanine
supplementSleep / calm focus
Research status · Dietary supplement
Dietary supplement (amino acid found in tea).
An amino acid from tea discussed for calm focus without sedation. Commonly paired with caffeine during the day (smoothing jitters) or taken in the evening as part of a wind-down.
How it works
Influences GABA/glutamate signaling and alpha-brain-wave activity, promoting relaxed alertness.
Commonly discussed use cases
- Calm focus (with caffeine)
- Evening wind-down
- Stress (discussed)
Supposed / potential benefits
- Reported smoother caffeine experience and subjective relaxation
Common side effects
- Well tolerated; occasional headache
Warnings & contraindications
- May modestly lower blood pressure — relevant if you're on BP medication
Typical timing considerations
With coffee (daytime) or 30–60 minutes before bed.
Administration route
Oral
Questions to ask your clinician
- Any interaction with my blood-pressure medication?
Commonly tracked in Reta
Tracking fields organize user-entered, clinician-directed routines — Reta never recommends or computes doses.
Sources
Track this in Reta
Beta members get a ready-made tracker for L-theanine — schedule, dose log, reminders, and check-ins — for organizing a clinician-directed routine. Personal tracking is available to everyone during the Public Beta.
Reta is a tracking and education tool — not a medical provider. Nothing here is a diagnosis, treatment, prescription, or dosing recommendation. Peptides and medications should only be used under the direction of a licensed clinician. Talk to a qualified clinician before starting, stopping, combining, or changing anything. Many compounds below are not FDA-approved for human use; some are investigational or sold through unregulated channels where purity and dosing are not guaranteed.