What it is
L-Theanine (Suntheanine) is an amino acid found predominantly in green tea, available in capsule form. It is used to promote relaxation and improve sleep quality.
Supplement · Mood, Anxiety & Emotional Balance
L-Theanine (Suntheanine)
500 mg · vegan · gluten-free · 90 caps
difficulty-falling-asleeprestless-sleepdaytime-fatigue braingut
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How it works
L-Theanine crosses the blood-brain barrier, influencing neurotransmitters like GABA, serotonin, and dopamine. It promotes alpha brain wave activity, leading to a state of calm focus and relaxation without sedation.
Who should take it
Adults looking to address difficulty falling asleep, restless sleep, daytime fatigue. Particularly relevant for people who prefer a targeted single ingredient and who have ruled out an underlying condition that needs medical care first.
Avoid / careful
Pregnant or nursing women without clinician oversight. People on prescription medication affecting the same pathway should consult a doctor before combining. Side effects are uncommon at recommended doses but mild GI upset can occur when starting.
When to take it
Morning
Noon
Evening
Night
How to take it
With food
Empty stomach
Before food
FAQs
Frequently asked
Can L-Theanine be taken during the day?
Yes, L-Theanine can be taken during the day to promote calm focus and reduce feelings of stress without causing drowsiness.
How long does it take to feel the effects of L-Theanine?
Noticeable effects on sleep and calm are typically observed within 1-3 weeks of consistent daily use.
Is Suntheanine different from regular L-Theanine?
Suntheanine is a patented, pure form of L-Theanine produced via a specific fermentation process, ensuring high quality and efficacy.
Research
6 studies · 2010–2024
Evidence grade
ABCD
C · C · emerging-to-moderate human evidence for sleep quality and relaxation
From the blog
Editorial notes
SacredBod's longer take on L-Theanine (Suntheanine) — context the structured blocks above don't capture.
About L-Theanine (Suntheanine)
L-Theanine (Suntheanine) is a mood, anxiety & emotional balance supplement used to support sleep quality and relaxation. Green-tea amino for calm focus and sleep. It is available in capsule form and dosed for adults in India and internationally. As a western-tradition entry in the SacredBod catalog, it is positioned as a single-ingredient option that can be used on its own or layered into a broader protocol. L-Theanine (Suntheanine) works through the mechanisms characteristic of its class — see the mechanism and research sections for detail. It primarily acts on the brain, nervous system, and effects are dose-dependent, typically becoming measurable within 1-3 weeks for noticeable sleep and calm. Consistency matters more than dose size for this category.
Evidence
L-Theanine (Suntheanine) carries an evidence grade of C in the SacredBod catalog, reflecting emerging human evidence for sleep quality and relaxation. Green-tea amino for calm focus and sleep. Benefits are cumulative rather than immediate, typically becoming noticeable within 1-3 weeks for noticeable sleep and calm, and individual response varies.
Dosing
A typical dose is 500 mg, taken with food, usually in the morning. Start at the lower end, assess tolerance, and stay consistent; more is not automatically better.
Cautions
Pregnant or nursing women without clinician oversight. People on prescription medication affecting the same pathway should consult a doctor before combining. Side effects are uncommon at recommended doses but mild GI upset can occur when starting.
Who it’s for
Adults looking to address difficulty falling asleep, restless sleep, daytime fatigue. Particularly relevant for people who prefer a targeted single ingredient and who have ruled out an underlying condition that needs medical care first.
As part of the Mood, Anxiety & Emotional Balance category, L-Theanine (Suntheanine) can be used on its own or layered into a broader protocol — see the Goes with panel for evidence-aligned pairings.
Added to your stack.