Thorne Glycine (250 capsules, 1 g per serving)
Best for: A single-ingredient amino acid with NSF Contents Certification
Single-ingredient glycine, NSF Contents Certified — 250 capsules at 500 mg each.
Glycine is an amino acid. Thorne's version is 500 mg per capsule (1 g per 2-capsule serving), third-party tested with NSF Contents Certification. 250 capsules per bottle.
Price & where to buy
Prices checked 2026-11-11Prices shown were last checked on 2026-11-11 and can change at any time — the price on the retailer's site at checkout is the one that applies. Product prices and availability are accurate as of the date/time indicated and are subject to change. Any price and availability information displayed on Amazon.com at the time of purchase will apply to the purchase of this product. 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 price at our recommended retailer as at our last check of that offer (2026-11-11) and, when Amazon reports one, its list price for comparison. Amazon prices come from Amazon's own product data service and are refreshed twice a day; each one shows the date and time Amazon gave it, and one older than 24 hours is replaced by “Check price”. Other retailers' prices are checked by hand and show the date of that check. Retail prices move constantly, so the price on the retailer's own page at checkout is the one that applies. More on Amazon prices
Should you buy it?
What we like
- NSF Contents Certified — a test of what's actually in the capsule
- Minimal excipients, single active ingredient
- Mildly sweet — capsules can be opened into water
- 250 capsules is a large bottle for the price
What to know before buying
- Bulk glycine powder elsewhere is far cheaper per gram
- 500 mg per capsule means a lot of capsules for a gram-scale intake
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At a glance
Compare with alternatives
Quick verdicts for the supplements most often considered alongside the Thorne Glycine (250 capsules, 1 g per serving).
Thorne Glycine (250 capsules, 1 g per serving) vs Doctor's Best High Absorption Magnesium Glycinate 200mg (240ct)
The highest-rated magnesium on Amazon — 240 tablets from Doctor's Best.
→ Value-focused buyers, athletes
Doctor's Best High Absorption Magnesium Glycinate 200mg (240ct) review →Thorne Glycine (250 capsules, 1 g per serving) vs NOW Foods L-Theanine 200mg (120ct)
The best-value L-theanine — 200mg per capsule, GMP-certified, and 120 servings per bottle.
→ Theanine at the lowest cost per capsule
NOW Foods L-Theanine 200mg (120ct) review →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, and a higher price than our value pick.
→ Drug-tested athletes, tablet-haters, flexible dosing
Thorne Magnesium Bisglycinate Powder (60 servings) review →Not sure which one is right for you?
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Frequently asked questions
How much glycine do studies use for sleep?
We don't publish dosing guidance — ask a pharmacist or your doctor.
Glycine vs magnesium glycinate — don't I already get glycine?
Magnesium glycinate is a chelate: magnesium bound to glycine, sold as a way of delivering the magnesium. This product is glycine on its own, with no magnesium in it. Different products, and the glycine amounts are not comparable.
What does glycine actually do for sleep?
See /natural-sleep-remedies for what the trial evidence actually shows.
Why not just buy bulk glycine powder?
You can, and it is cheaper per gram. Thorne's premium buys NSF Contents Certification — an independent test of what is actually in the capsule — plus a clean excipient list. That is what you are paying for, not economy.