Glycine
Compiled from published pharmacological and botanical literature. Not independently verified by Herbuno. Spotted an error or have a correction? Flag it below →
| Compound | Glycine |
|---|---|
| Chemical class | Simplest proteinogenic α-amino acid — a single hydrogen as side chain; achiral |
| CAS | 56-40-6 |
| Primary source | Chemical synthesis from chloroacetic acid and ammonia; also by fermentation |
| Key applications | Collagen structure, glutathione synthesis, inhibitory neurotransmission, bile acid conjugation, sleep quality |
| Claim strength | Moderate for sleep quality; High for its structural role in collagen; Emerging elsewhere |
| Typical form | Crystalline powder at 99%, free-flowing, naturally sweet |
| Buy from Herbuno | Glycine 99% Powder |
| Origin | Processed / Sourced from India |
| MOQ | R&D 100 g / 250 g (subject to stock) · Pilot batch 1–5 kg · Bulk 10 kg, 25 kg and above |
| Lead Time | Dispatch within 72 hrs from stock · fresh-batch production (typically 50 kg+): 10 working days |
| Documentation | CoA & MSDS standard with every lot |
Name origin: From the Greek glykys, sweet. Henri Braconnot isolated it from acid-hydrolysed gelatin in 1820 and named it for its taste, which is genuinely sugar-like at around 70% the sweetness of sucrose. It was briefly called glycocoll. It is the only achiral amino acid — with a lone hydrogen atom as its side chain there is no asymmetric centre — so there is no L- or D- form, which is why it is simply glycine rather than L-glycine.
Discovery and production history: Glycine was the first amino acid isolated from a protein, which makes it the starting point of the entire field. Its structural significance became clear once collagen was sequenced: glycine occupies every third residue in the collagen triple helix, a position no other amino acid can fill because any side chain larger than hydrogen will not fit in the helix interior. Industrial production is by chemical synthesis, typically amination of chloroacetic acid, with fermentation routes also in use.
Research trajectory: Glycine was long classified as non-essential and largely ignored, on the reasoning that the body synthesises it from serine. Work from the 2000s onward questioned whether endogenous synthesis actually meets demand, since glycine is consumed in large quantities by collagen turnover, glutathione synthesis and bile acid conjugation simultaneously. Several analyses suggest a shortfall of a few grams daily relative to full requirement, which reframes glycine as conditionally essential. Separately, a small Japanese trial literature on pre-sleep glycine created the sleep category.
Commercial source: Supplement glycine is produced synthetically at 99% or higher purity and supplied as a free-flowing crystalline powder. Because the molecule is achiral there is no optical purity question and no cheaper D- or DL- material to guard against, which simplifies specification relative to other amino acids. The meaningful quality variables are impurity profile from the synthesis route and heavy metals.
Evidence for Glycine Applications
The sleep evidence is real but should not be oversold. A small set of Japanese trials gave 3 grams of glycine before bed to people with subjective sleep complaints and reported improved sleep quality ratings, shortened time to sleep onset, reduced daytime fatigue, and objective polysomnographic changes including faster progression to slow-wave sleep. The proposed mechanism is peripheral vasodilation lowering core body temperature, which is a normal sleep-onset signal, possibly alongside NMDA receptor co-agonism centrally. Trials are few and small, mostly from the same research group, and sample sizes are in the tens. The direction is consistent; the evidence base is thin. Claim strength: Moderate.
Glycine's structural role in collagen is unambiguous and routinely over-extrapolated. Collagen's triple helix requires glycine at every third position, and no substitution is possible because any larger side chain sterically prevents helix formation. This makes glycine quantitatively the most abundant amino acid in collagen and a genuine requirement for collagen synthesis. It does not follow that supplementing glycine increases collagen deposition in skin or joints, which is the consumer claim. Controlled human trials demonstrating that outcome are absent. Being a required input is not the same as being the rate-limiting one. Claim strength: High for the biochemistry, Emerging for the consumer claim.
The conditional-essentiality argument is the most interesting current line and remains unsettled. Analyses comparing endogenous glycine synthesis against the combined demands of collagen turnover, glutathione production and bile acid conjugation suggest a shortfall in the region of a few grams daily. If correct, this would mean most people operate in a mild glycine-limited state, with implications for glutathione status in particular. The analyses are based on flux calculations rather than on depletion-repletion trials with clinical endpoints, so the conclusion is plausible rather than demonstrated. Claim strength: Emerging.
Glutathione synthesis is where the mechanistic case is strongest outside collagen. Glutathione is a tripeptide of glutamate, cysteine and glycine, and while cysteine is usually described as the limiting substrate, some work in older adults has found that combined glycine and cysteine supplementation restored glutathione synthesis rates and lowered oxidative stress markers more than cysteine alone. This suggests glycine availability can be co-limiting in ageing, which is a narrower and better-supported claim than general antioxidant positioning. Claim strength: Moderate.
Metabolic and cardiometabolic associations are observational and should stay that way in any claim. Low plasma glycine is consistently associated with insulin resistance, type 2 diabetes and cardiovascular events across cohort studies, and the association is strong enough to have generated considerable interest. Whether low glycine causes metabolic dysfunction or simply marks it is unresolved, and intervention trials demonstrating that raising glycine improves metabolic outcomes are not available. This is a research-stage observation, not a product claim. Claim strength: Emerging.
Tolerability is excellent and the sweetness is a genuine formulation asset rather than a footnote. Doses of 3 to 15 grams daily have been used without significant adverse effects, and glycine is used in intravenous irrigation solutions at scale, which speaks to its safety profile. No tolerable upper intake level has been established. At around 70% the sweetness of sucrose with a clean profile and no bitter back-note, glycine can offset the taste of harsher amino acids in a blend, reducing or removing the need for separate sweetening — a practical advantage few other actives offer. Claim strength: High.
Sourcing glycine from Herbuno. We supply glycine at 99% as a free-flowing crystalline powder suitable for sachets, powder blends, capsules and beverage applications.
Worth knowing at the formulation stage: glycine's sweetness can carry some of the flavour load in an amino acid blend, which often reduces the sweetener system needed elsewhere in the formula. All lots ship with CoA and MSDS as standard; request a quotation for pilot or bulk volumes.
Dosage & Formulator Specification
Glycine is dosed as the free amino acid at 99% or above, so declared weight is delivered weight, and because it is achiral there is no stereoisomer conversion to account for. The sleep protocol from the trial literature is 3 grams taken shortly before bed, which is the dose to replicate if that is the claim being supported. Collagen-support positioning typically uses 5 to 10 grams daily, and glutathione-oriented protocols have used comparable amounts alongside a cysteine source such as N-acetylcysteine.
At 3 grams this is a borderline capsule product — roughly six size-00 capsules — and at 5 to 10 grams it is unambiguously a powder, sachet or stick-pack ingredient. The sweetness makes that considerably easier than it would be for most amino acids, since a 5 gram glycine serve in water is palatable without masking, which is not true of arginine, lysine or most branched-chains. For sleep products the format question is also a timing one: a powder stirred into water before bed is a different consumer ritual from a capsule, and the trial protocol used a dissolved dose.
Formulation handling is about as easy as actives get. Glycine is stable across a wide pH range, stable to heat, freely soluble in water at around 25 grams per 100 millilitres at room temperature, not notably hygroscopic, and compatible with the common excipients and co-ingredients. It participates in Maillard reactions with reducing sugars on heating, which is relevant for bars and thermally processed formats and can produce browning and off-notes. It also acts as a buffering agent in solution, which can shift the pH of a formula in ways worth checking rather than assuming.
For analytical control, specify identity and assay by HPLC or ion-exchange chromatography. Optical rotation does not apply, since glycine is achiral — a point worth knowing so that an inappropriate specification is not written. Standard amino acid requirements cover heavy metals, residual solvents, chloride where the chloroacetic acid route is used, microbiological limits and loss on drying. For fermentation-derived material the certificate should name the organism and substrate. Glycine is synthetic or fermentation-derived rather than plant-extracted, so phytosanitary certification does not apply; CoA and MSDS ship as standard.
Frequently Asked Questions — Glycine
Does glycine actually help sleep?
The evidence points that way but it is thin. A small set of Japanese trials using 3 g before bed reported improved sleep quality, faster onset and reduced daytime fatigue, with supporting polysomnography. The proposed mechanism — peripheral vasodilation lowering core temperature — is plausible. But the trials are few, small, and largely from one group. Consistent direction, limited base.
Will glycine build collagen?
It is required for collagen — every third residue in the triple helix must be glycine, because nothing larger fits. That does not mean supplementing it increases collagen deposition in skin or joints, and controlled human trials showing that are absent. Being a required input is not the same as being the rate-limiting one, and the consumer claim depends on conflating the two.
Is glycine actually non-essential?
That classification is under genuine question. Flux analyses comparing endogenous synthesis against the combined demands of collagen turnover, glutathione production and bile acid conjugation suggest a shortfall of a few grams daily. If right, most people run mildly glycine-limited. It is a calculation rather than a depletion-repletion trial result, so treat it as plausible, not established.
Can glycine replace sweetener in a blend?
Partly, and it is one of the few actives that earns its place on taste alone. Glycine is about 70% as sweet as sucrose with a clean profile and no bitter back-note, so in an amino acid blend it offsets harsher components and often reduces the sweetener system needed. A 5 g glycine serve in water is palatable unmasked, which is not true of arginine or the branched-chains.
Does optical rotation need specifying?
No — glycine is achiral. With a single hydrogen as its side chain there is no asymmetric centre, so there is no L- or D- form and no cheaper DL- material to guard against. That simplifies the specification relative to every other amino acid. Specify assay by HPLC or ion-exchange, plus chloride if the chloroacetic acid route is used.
Why source glycine from India?
Around 80% of raw nutraceutical ingredients originate in China, with amino acids among the most concentrated categories, so a second qualified origin is a continuity measure rather than a price play. India has established synthetic and fermentation amino acid capacity with the documentation infrastructure these buyers typically require.