L-Theanine
Also known as: Theanine
L-theanine is an amino acid found in tea. People commonly explore it for a sense of calm focus, sometimes paired with caffeine to smooth its effects. Evidence is preliminary but generally favorable for relaxation contexts.
Snapshot
Evidence level is outcome-specific; a supplement can have stronger evidence for one use and limited evidence for another.
What this page can tell you: Commonly discussed timing, food notes, caution categories, and an honest note on how much source review this entry still needs.
What it cannot: Whether this is appropriate for you personally, or that it treats, prevents, or cures any condition. Informational only — discuss with a clinician or pharmacist.
🕒 Timing
When: Morning, Anytime, Bedtime
Food: With or without food
Flexible; commonly paired with caffeine in the morning (a rough 2:1 theanine-to-caffeine ratio is popular) or used alone later in the day. No food is needed - it can be taken with or without.
💊 Common use range
100–200 mg
Generally well tolerated; more is not necessarily better.
Ranges are informational, not a recommended dose. Talk to a professional about what is right for you.
⚠️ Commonly noted interactions (supplements)
None listed.
Often about absorption or timing rather than danger — separating doses is common. This list is not exhaustive.
🧭 Baseline caution
General caution for ordinary, common use — before accounting for your specific dose, medications, health history, or procedures.
No general caution factors flagged for ordinary use. See context alerts below for situations that may still apply to you.
Caution level is an informational summary of commonly discussed caution categories and doses — not a safety rating, approval, or medical advice. Low caution does not mean safe for you.
🔎 Context alerts to review
Context alerts may matter depending on your dose, medications, health history, or procedure plans — they do not mean the supplement is generally risky at ordinary use.
Medications
- Sedating — don't combine with alcohol or sedatives
- Higher caution if you take blood-pressure medication
- Sedative / CNS-depressant interaction
Evidence still under review
- Evidence not fully source-reviewed yet
🩺 Medication caution categories
- Blood pressure medication — Some items can nudge blood pressure on their own, so combined with blood-pressure medication the effects could add up. Discuss monitoring with your clinician.
- Sedatives / CNS depressants — Sedating items can add to the drowsiness of sleep aids, sedatives, or alcohol — the combined effect is the concern.
🏥 Surgery & procedure caution
Not a well-established surgical concern; share your supplement list.
If you have a procedure scheduled, bring your full supplement list to your surgical and anesthesia team. Do not stop prescribed medication unless your clinician tells you to. Do not start or stop supplements based only on this app.
✅ Quality checklist
- Prefer products with third-party testing or a certificate of analysis (COA).
- Check the label for the exact form and the elemental or active amount per serving.
🧩 Commonly paired with
🔁 Alternatives
🗣️ Questions for a professional
- Is L-Theanine appropriate alongside my medications and health history?
- Is there a test or check that would tell us whether I actually need it?
🔬 Evidence snapshot
Overall evidence level here is listed as "Limited evidence". A detailed, source-reviewed evidence summary has not been completed yet.
🧪 Forms & quality
Source type: Amino acid
The 'L-' in L-theanine refers to the molecule's stereochemical configuration — the naturally occurring form of the amino acid found in tea — not 'left' or 'better'.
See the supplement glossary for what form names like "L-", chelated, or standardized extract mean.
📏 Dose & monitoring
Needs evidence review — no source-reviewed information yet. We only show dose and monitoring details after they have been checked against reputable sources.
Evidence vs. burden: Not yet reviewed
😐 Commonly reported side effects
- Uncommon; occasional headache
Non-exhaustive and individual.
🔄 Cycling & breaks
Not typically cycled.
📅 Daily use notes
Often paired 1:2 with caffeine (e.g., 100 mg caffeine + 200 mg theanine) for focus.
📋 Source review status
Needs evidence review
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