L-Theanine vs Glycine
Independent, side-by-side comparison of L-Theanine and Glycine: mechanism, half-life, dose range, safety profile, and live vendor pricing. Updated continuously as new research and listings land.
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L-Theanine
Glycine
L-Theanine
L-Theanine is a non-proteinogenic amino acid found almost exclusively in tea (Camellia sinensis) and a handful of edible mushrooms, and it has become the single most widely-used calm-focus nootropic in the modern…
Live lowest price: $85.00 across 1 vendor
Full L-Theanine profileGlycine
Glycine is the simplest amino acid—a single hydrogen atom replacing the typical side chain found in other proteinogenic amino acids—yet it performs an wide range of biological functions. Despite being classified as…
Full Glycine profileSide-by-side comparison
| Attribute | L-Theanine | Glycine |
|---|---|---|
| Category | Nootropics | Foundational |
| Research Stage | FDA Approved | Preclinical |
| Mechanism of Action | L-Theanine is a weak, broad-spectrum neurotransmitter modulator that produces its "relaxed alertness" signature through small simultaneous effects on glutamate, GABA, monoamines, and cortical oscillatory activity — rather than through strong action at any… | Glycine acts through multiple distinct and non-redundant mechanisms, explaining its extraordinarily broad range of biological effects. Understanding these mechanisms clarifies when supplementation is likely to produce clinically meaningful benefit versus when… |
| Half-Life | 1-3 hours (plasma); central CNS effect 3-5 hours | — |
| Typical Dose Range | — | — |
| Dosing Frequency | — | — |
| Administration | Oral | — |
| Side Effects | L-theanine has one of the cleanest safety profiles of any CNS-active nootropic, with no dependence, withdrawal, tolerance, or serious adverse events reported in controlled trials at doses up to 900mg/day for weeks to months. Common mild side effects (all… | Glycine has an exceptional safety profile across extensive clinical use. Doses up to 60 g daily have been used in schizophrenia trials without systematic serious adverse effects. For typical supplementation doses (3-15 g daily), side effects are uncommon and… |
| Molecular Weight | 174.20 g/mol | — |
| Common Vial Sizes | — | — |
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Frequently asked
What's the difference between L-Theanine and Glycine?
L-Theanine is a nootropics that l-theanine is a weak, broad-spectrum neurotransmitter modulator that produces its "relaxed alertness" signature through small simultaneous effects on glutamate, gaba, monoamines,…. Glycine is a foundational that glycine acts through multiple distinct and non-redundant mechanisms, explaining its extraordinarily broad range of biological effects. understanding these mechanisms clarifies when…. The two differ in mechanism, half-life (1-3 hours (plasma); central CNS effect 3-5 hours vs not reported), and typical dose range.
Which has the longer half-life, L-Theanine or Glycine?
L-Theanine has a half-life of 1-3 hours (plasma); central CNS effect 3-5 hours. Glycine has a half-life of not reported. Longer half-lives generally mean less frequent dosing but slower on/off kinetics.
Can you stack L-Theanine and Glycine?
Stacking depends on mechanism overlap, safety profile, and goals. L-Theanine and Glycine should only be stacked after reviewing each compound's individual protocol page, side effect profile, and any published interaction data. Use the BodyHackGuide stack builder for a structured review before combining research compounds.
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Research use only. BodyHackGuide is an independent research reference. The compounds discussed on this page are not approved by the FDA for human consumption and are sold strictly for laboratory research. Prices shown are pulled from vendor listings tracked on BHG and are subject to change. We earn an affiliate commission on some outbound clicks — this never affects the data or pricing shown. See editorial standards and affiliate disclosure.
