Overview
Pharmaceutical-grade L-theanine.
- Dietary protein from animal sources (meat, fish, eggs, dairy) and plant sources (soy, legumes, grains)
- Free-form amino acid powders and capsules
- Targeted pre-workout, recovery, or sleep formulations
- Free-form crystalline powder
- Capsules or tablets
- Pre-mixed recovery or hydration beverages
- Time-release formulations
Mechanism of action
Same as L-theanine; >99% purity.
- · Same as L-theanine
- · >99% purity
Effects on the body
Organ system effects
Suntheanine modulates monoaminergic and GABAergic tone relevant to mood and anxiety regulation.
Evidence-based benefits
Promotes relaxation
Moderate evidencePotential side effects
- · Well tolerated
Drug interactions
Supplement interactions
- Omega-3 (EPA/DHA)Membrane fluidity and neuronal signaling support.
- Alpha-GPC or CDP-cholineProvides choline substrate for acetylcholine synthesis.
No specific avoidances listed.
Dosing & bioavailability
Where to buy
Affiliate links — we may earn a commission at no extra cost to you. Amazon code supplementsch-20 is auto-applied at checkout. We don't endorse specific brands; verify third-party testing (USP, NSF, Informed Sport) before purchase.
Third-party testedIndependently verified Suntheanine — look for USP, NSF, or Informed Sport seals on the label for purity and dose accuracy.Suntheanine third party tested NSF
CapsulesPre-measured Suntheanine capsules — easiest for travel and consistent daily dosing without scoops or scales.Suntheanine capsules
PowderBulk unflavored Suntheanine powder — best cost-per-gram and flexible dosing for stacking or mixing into drinks.Suntheanine powder unflavored
Best sellersMost-purchased Suntheanine products on Amazon — a quick way to see what's reviewed widely before you commit.Suntheanine best sellerScientific evidence8Show studiesHide studies
Suntheanine and stress
Kimura K, et al.
12 healthy adults
Reduced stress markers during cognitive task.
PubMed: Suntheanine — Promotes relaxation
Live PubMed search
Live results for "Suntheanine Promotes relaxation" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "Promotes relaxation". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Suntheanine — randomized controlled trial
Live PubMed search
Live results for "Suntheanine randomized controlled trial" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "randomized controlled trial". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Suntheanine — meta-analysis
Live PubMed search
Live results for "Suntheanine meta-analysis" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "meta-analysis". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Suntheanine — pharmacokinetics
Live PubMed search
Live results for "Suntheanine pharmacokinetics" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "pharmacokinetics". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Suntheanine — safety adverse events
Live PubMed search
Live results for "Suntheanine safety adverse events" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "safety adverse events". Filter by RCT, meta-analysis, or year on the results page.
PubMed: Suntheanine — dose response
Live PubMed search
Live results for "Suntheanine dose response" across the PubMed/MEDLINE peer-reviewed index.
Opens current human and preclinical literature matching Suntheanine and "dose response". Filter by RCT, meta-analysis, or year on the results page.
Google Scholar: Suntheanine — clinical evidence
Live Scholar search
Cross-database citation index for Suntheanine as it relates to "clinical evidence".
Includes preprints, theses, and journal articles. Useful for tracking citation counts and follow-on work.