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SUPPLEMENTS·THORNE
Thorne Glycine (250 capsules, 1 g per serving)
4.8 · 77 reviews
Editor score8.5/10
Best for: Magnesium/theanine users wanting a third option, warm sleepers (glycine's mechanism relates to core temperature)
Price
Check price
At Amazon · price changes often, check before buying
Buy at Amazon ↗Updated 2026-08-02
Dose per serving
1 g glycine (2 capsules)
Studied sleep dose
3 g (6 capsules), 30-60 min before bed
Count
250 capsules
The catalog's third amino-acid relaxation option — the 'what else besides melatonin' answer, NSF Contents Certified.
Glycine is the amino acid the sleep-curious ask about after magnesium and L-theanine: research protocols commonly use 3 g before bed, associated in small studies with falling asleep faster and better-rated sleep quality. Thorne's version is 500 mg per capsule (1 g per 2-cap serving), third-party tested with NSF Contents Certification, and clean-label (just glycine plus capsule). The honest math: the studied 3 g dose means 6 capsules a night, which turns the 250-count bottle into a ~6-week supply.
Price across 2 retailers
Prices checked 2026-08-02Prices shown were last checked on 2026-08-02and can change at any time — the price on the retailer's site at checkout is the one that applies. As an Amazon Associate and affiliate we may earn a commission on purchases made through these links, at no extra cost to you.
How our prices work
We show the lowest price we found at our last check (2026-08-02) and the manufacturer's list price for comparison. Retail prices — Amazon's especially — move constantly, so treat these as a guide: the price shown on the retailer's own page at checkout is the one that applies. Tap through to see each retailer's current price.
Should you buy it?
What we like
- New ingredient for the lineup — no overlap with magnesium or theanine
- NSF Contents Certified, minimal excipients
- Mildly sweet — capsules can be opened into water
- Stackable with magnesium and L-theanine
What to know before buying
- Studied dose = 6 capsules/night — tedious and triples effective cost
- Evidence base is small studies, not large trials
- Bulk glycine powder elsewhere is far cheaper per gram
At a glance
Dose per serving1 g glycine (2 capsules)
Studied sleep dose3 g (6 capsules), 30-60 min before bed
Count250 capsules
FormCapsule (openable — mildly sweet powder)
CertificationNSF Contents Certified
Other ingredientsCalcium laurate, cellulose, hypromellose
StackingCombines with magnesium / L-theanine
CautionConsult a doctor if pregnant (brand guidance)
Best forNon-melatonin sleep support
How it scores
How our 8.5/10 breaks down — rated on the dimensions that matter most for supplements, from hands-on testing and verified specs, not the marketing.
Evidence
7.5/10
Dosing
7/10
Purity
9.5/10
Gentleness
9.5/10
Value
7/10
Compare with alternatives
Quick verdicts for the supplements most often considered alongside the Thorne Glycine (250 capsules, 1 g per serving).
VS·HEAD-TO-HEAD
Thorne Glycine (250 capsules, 1 g per serving) vs Doctor's Best High Absorption Magnesium Glycinate 200mg (240ct)
The highest-rated magnesium on Amazon for sleep — glycinate form is chelated for maximum absorption without laxative effects.
→ Restless legs, muscle tension, anxiety-driven insomnia, athletes
VS·HEAD-TO-HEAD
Thorne Glycine (250 capsules, 1 g per serving) vs NOW Foods L-Theanine 200mg (120ct)
The best-value pure L-theanine — 200mg per capsule, GMP-certified, and $17 for 120 servings.
→ Anxiety-driven insomnia, ruminating minds, stackers with melatonin
VS·HEAD-TO-HEAD
Thorne Glycine (250 capsules, 1 g per serving) vs Thorne Magnesium Bisglycinate Powder (60 servings)
The athlete-grade magnesium — NSF Certified for Sport, powder format, same chelate as our value pick at three times the price.
→ Drug-tested athletes, tablet-haters, flexible dosing
Decision support · what no other comparison site has
Take the quiz · 60 secNot sure which one is right for you?
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Frequently asked questions
How much glycine do studies use for sleep?
Commonly 3 g taken 30-60 minutes before bed — that's 6 of these capsules, not the 2-capsule label serving. Plan the bottle math around 6/night (~6 weeks per bottle) if you're following the research protocol.
Glycine vs magnesium glycinate — don't I already get glycine?
Magnesium glycinate carries some glycine, but far below 3 g per dose. They're complementary: the chelate is a magnesium delivery form; this is glycine at research-relevant amounts.
What does glycine actually do for sleep?
Small studies associate 3 g pre-bed with falling asleep faster and better-rated sleep quality, likely via a small drop in core body temperature. The evidence is promising but modest — treat it as 'supports relaxation', not a cure.
Why not just buy bulk glycine powder?
You can, cheaper per gram. Thorne's premium buys NSF Contents Certification, dosing convenience, and a clean excipient list — worth it for certainty, not economy.
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