Verified Supplement Data Primary-sourced

Best Magnesium Glycinate 2026: Dose, Verification, Cost

By Erin Rose · Published · Reviewed against primary sources · Methodology · About Us

Not medical advice. This summarizes absorption trials, the labels manufacturers file with the NIH, and current Amazon prices. Magnesium supplements need a clinician's say-so with kidney disease, and they interact with some antibiotics and bisphosphonates.

Quick answer

The best magnesium glycinate is one whose capsule carries a full dose of elemental magnesium, whose label has been checked by someone other than the maker, and which costs the least per 200 mg after those two tests. Most of the shelf fails the first test before price enters: on the 149 NIH glycinate labels we read, the median capsule holds 111 mg and 78.5% of products need two or more capsules to reach the number on the front; of the labels named glycinate, 19.3% quietly blend in another form.

Best overall: Nature Made Magnesium Glycinate 200mg, 200 mg in one capsule, USP Verified, $0.19 per 200 mg. Certified for sport: Thorne Magnesium Bisglycinate, 200 mg per capsule, NSF Certified for Sport, $0.43. Best value: Vitamin Shoppe Magnesium Glycinate 400mg, 200 mg per tablet, $0.11 per 200 mg, no third-party mark. See the ranking →

Supplemental limit, adults350mg elemental / day · NIH ODS · dosage guide
Magnesium oxide absorbed~4%chloride, lactate, aspartate higher and equal · Firoz 2001
Glycinate labels needing 2+ capsules 78.5% 149 labels read · our census

Only buying on price? The same 10 products ranked purely by cost per 200 mg: cheapest magnesium glycinate →

On this page
  1. The three rules
  2. Ranked
  3. Which to buy
  4. What the labels sell
  5. Glycinate vs the others
  6. Dose and timing
  7. FAQ

The three rules that decide a magnesium glycinate

1. Dose by the Supplement Facts row, and want at least 100 mg of it per capsule. The row that says “Magnesium” is elemental magnesium. A front label that says “magnesium bisglycinate 2,000 mg” is quoting the whole compound, of which about 14% is magnesium. The census below found the median glycinate capsule holds 111 mg, so the typical bottle needs 4 capsules for a 400 mg serving. A capsule under 100 mg means four or more pills for the dose most sleep trials used, which is the dose people stop taking. Of the 8 capsules and tablets we track, 1 fails this test: Nutricost Magnesium Glycinate 210 mg (70 mg per capsule).

2. Prefer a label someone else has checked. In the one head-to-head of US commercial magnesium products, magnesium oxide was about 4% absorbed while the chloride, lactate and aspartate salts were significantly higher and equivalent to one another (Firoz 2001, PMID 11794633), and a 2021 systematic review of bioavailability studies found the organic forms consistently ahead of oxide but the product-to-product variation wide (Pardo 2021, PMID 34111673). What the capsule actually contains matters, and a USP Verified or NSF mark is the only evidence on the shelf that a third party tested it. 2 of the 7 products passing rule 1 carry one: Nature Made Magnesium Glycinate 200mg (USP Verified) and Thorne Magnesium Bisglycinate (NSF Certified for Sport). A GMP or Non-GMO mark is a factory or sourcing audit, not a test of the finished product, so it does not count here.

3. Then the lowest cost per 200 mg. Across the 10 products the spread is 4.9× for the same form, from $0.089 to $0.433 per 200 mg. Over a year at one 200 mg dose a day that is $32.40 against $158.17. Price decides only after the first two rules, which is why the cheapest product on the shelf is not the best one below.

Every magnesium glycinate we track, ranked

Doses are the elemental magnesium on each product’s Supplement Facts panel; prices are the current Amazon price for the exact container. Cost per 200 mg is price divided by total elemental magnesium in the container, times 200. The “per capsule” column decides rule 1; the “mark” column decides rule 2.

Magnesium glycinate products we track, cheapest per 200 mg of elemental magnesium first, with the per-capsule dose and any third-party mark on the label.
ProductPer 200 mgElemental per capsuleCapsules for 400 mgServing on labelServingsPriceMark on labelBuy
BulkSupplements Magnesium Glycinate Powderbest powder $0.089 powder measured 225 mg / 1250 mg powder (~1/2 tsp) 200 $19.97 none stated Check price
Vitamin Shoppe Magnesium Glycinate 400mgbest value $0.111 200 mg 2 400 mg / 2 tablets 90 $19.99 none stated Check price
NOW Magnesium Bisglycinate Powder $0.151 powder measured 250 mg / 1 level teaspoon (~2.9 g) 78 $14.69 NPA GMP Certified, Non-GMO Project Verifiednot a product test Check price
Nutricost Magnesium Glycinate 210 mg $0.174 70 mg under 100 6 210 mg / 3 capsules 120 $21.95 none stated Check price
Nature Made Magnesium Glycinate 200mgbest overall $0.195 200 mg 2 200 mg / 1 capsule 60 $11.70 USP Verified Check price
NOW Magnesium Glycinate 200 mg $0.218 100 mg 4 200 mg / 2 tablets 120 $26.12 NPA GMP Certifiednot a product test Check price
Doctor's Best High Absorption Magnesium $0.233 100 mg 4 200 mg / 2 tablets 60 $13.99 none stated Check price
Nature's Bounty High Absorption Magnesium Glycinate 240 mg $0.240 120 mg 4 240 mg / 2 capsules 60 $17.29 none stated Check price
KAL Magnesium Glycinate 400 $0.275 200 mg 2 400 mg / 2 tablets 45 $24.79 none stated Check price
Thorne Magnesium Bisglycinatecertified for sport $0.433 200 mg 2 200 mg / 1 capsule 60 $26.00 NSF Certified for Sport Check price

Two powders sit at the cheap end because a scoop carries no capsule cost: BulkSupplements Magnesium Glycinate Powder at $0.089 per 200 mg is 2.2× cheaper than the best-overall pick. The trade is measuring a dose by the half-teaspoon and a strongly bitter taste. Nutricost Magnesium Glycinate 210 mg is the cheapest capsule per 200 mg but carries 70 mg per capsule, so a 400 mg dose is 6 capsules, which is why it fails rule 1 and is not a pick.

Which magnesium glycinate to buy

Product links go to Amazon and we may earn a commission if you buy. It never changes which product we pick or what we say about it. How we choose.

Best overall
Nature Made Magnesium Glycinate 200mg $0.19 per 200 mg
200 mg of elemental magnesium in one capsule, 60 capsules, USP Verified on the label. The only glycinate we track that passes all three rules: a whole 200 mg dose per capsule, a product-verification mark, and the lowest price among the verified products. Two capsules is a 400 mg evening dose, which is above the 350 mg supplemental limit, so one is the default and two is a decision.

Check price →

Certified for sport
Thorne Magnesium Bisglycinate $0.43 per 200 mg
200 mg per capsule as bisglycinate, 60 capsules, NSF Certified for Sport, the mark that screens each lot for banned substances as well as content. 2.2× the price of Nature Made Magnesium Glycinate 200mg for the same dose per capsule. The right pick for a tested athlete; for anyone else it buys a stricter audit, not more magnesium.

Check price →

Best value, no mark
Vitamin Shoppe Magnesium Glycinate 400mg $0.11 per 200 mg
200 mg per tablet, 400 mg per 2 tablets, 90 servings. 1.8× cheaper than Nature Made Magnesium Glycinate 200mg per 200 mg and a whole dose per tablet, but no third-party mark on the label, so you are trusting the maker’s own testing. The pick when the budget decides and you take one tablet, not the two the label directs.

Check price →

Best powder
BulkSupplements Magnesium Glycinate Powder $0.089 per 200 mg
225 mg of elemental magnesium per 1250 mg powder (~1/2 tsp), 200 servings, the lowest cost per 200 mg on the page. For someone who dislikes capsules or wants to set an exact dose. It is bitter, and a level measure matters: the dose scales with the scoop, not a pill count.

Check price →

We read 149 magnesium glycinate labels: the capsule and the front label disagree

Original research827 magnesium labels retrieved from the NIH Dietary Supplement Label Database; 149 list a glycinate or bisglycinate form in the magnesium row and 57 of those carry the word in the product name. Elemental magnesium per serving and per unit were read from the Supplement Facts panel. Every figure was recomputed in both halves of the read order in each population; 8 of 10 held among the 149 and 5 of 10 among the 57, and a figure is printed only from a population in which it held.

The median product directs 250 mg of elemental magnesium per serving, but the median capsule holds 111 mg, because 78.5% of products define a serving as two or more capsules. 78.5% of labels reach 200 mg per serving and 32.9% reach 400 mg; at the median capsule, 400 mg is 4 capsules. And “glycinate” on the front is not a guarantee of glycinate inside: among the 57 labels named glycinate, 19.3% list another magnesium form in the same row, most often oxide, the least absorbed form, which pads the milligram number without adding much magnesium you keep. (The oxide share itself did not survive validation and is not printed.)

What a label named magnesium glycinate delivers
0% 25% 50% 75% 100% Serving is 2+ capsules 78.5% Serving is 200 mg or more 78.5% Serving is 400 mg or more 32.9% Named glycinate: blends another form 19.3%
Of 149 NIH labels listing a glycinate form, 78.5% need two or more capsules per serving, 78.5% direct at least 200 mg and 32.9% at least 400 mg per serving; of the 57 named glycinate, 19.3% blend in another magnesium form. Source: Our census of 149 DSLD magnesium glycinate labels; validated split-half.
What a label named magnesium glycinate delivers
ItemValue (%)
Serving is 2+ capsules78.5%
Serving is 200 mg or more78.5%
Serving is 400 mg or more32.9%
Named glycinate: blends another form19.3%
How we read the labels, and what did not hold

Method: labels sold as magnesium whose product name says glycinate or bisglycinate; Supplement Facts magnesium row is elemental mg per serving; per unit = per serving / units per serving. Labels retrieved 2026-08-27. Each finding was recomputed in the two halves of the read order (shares must agree within 8 points, medians within 25%) and printed only from a population in which the halves agreed; the share blending oxide failed in both populations and is not printed, and the blend share is printed only for the 57 labels named glycinate, the population in which it held. The census and the cost table are published as open data at /magnesium/best-glycinate.json (CC BY 4.0). What it cannot tell you: how much of each product sells, whether a capsule contains what its label says, or how much magnesium a given person absorbs.

Glycinate against the other forms: what the trials measured

The case for glycinate is tolerance, not a large absorption edge. Firoz and Graber gave healthy volunteers four commercial products and measured urinary magnesium: oxide was about 4% absorbed, while the chloride, lactate and aspartate salts were significantly higher and equivalent to one another (Firoz 2001, PMID 11794633). Walker’s randomized trial found citrate more bioavailable than oxide and slightly ahead of amino-acid chelate on some measures (Walker 2003, PMID 14596323), and the 2021 systematic review reads the whole literature the same way: organic salts and chelates ahead of oxide, differences among the organic forms small and study-dependent (Pardo 2021, PMID 34111673). In patients with a shortened bowel, where absorption is hardest, diglycinate outperformed oxide (Schuette 1994, PMID 7815675).

Where glycinate separates is the gut. Citrate and oxide pull water into the bowel, which is why citrate is sold as a laxative at gram doses and why 400 mg of either loosens stools in a meaningful share of people. Glycinate, bound to an amino acid, generally does not, so it is the form that survives months of nightly use. The full comparison, including the sleep and anxiety evidence by form, is at glycinate vs citrate and eight forms compared.

Dose and timing

The RDA is 310 to 320 mg a day for women and 400 to 420 mg for men, counting food. The NIH sets the tolerable upper intake for supplemental magnesium at 350 mg a day for adults, the point above which diarrhea becomes common; food magnesium does not count against it. Most people who supplement need 100 to 200 mg to close the gap between diet and the RDA, which is one capsule of the pick above, not the two-capsule serving many labels direct. The dosage guide walks through the arithmetic by diet and by goal.

For sleep, the trials used 320 to 500 mg of elemental magnesium in the evening. A meta-analysis of three randomized trials in older adults with insomnia found sleep onset shortened by about 17 minutes on low-quality evidence (Mah 2021, PMID 33865376); the glycine in glycinate has its own small record, with 3 g before bed improving subjective sleep quality in a Japanese crossover study (Bannai 2012, PMID 22293292), though a 200 mg magnesium capsule carries only about 1.2 g of glycine. Take it 30 to 60 minutes before bed, away from any quinolone or tetracycline antibiotic and from bisphosphonates by at least two hours. People on thiazide diuretics lose magnesium and are the group most likely to be short (Kieboom 2018, PMID 30095199). See best time to take magnesium and side effects by form.

Frequently asked questions

What is the best magnesium glycinate supplement?

Nature Made Magnesium Glycinate 200mg: 200 mg of elemental magnesium in one capsule, USP Verified on the label, $0.19 per 200 mg. It is the only glycinate we track that combines a single-capsule 200 mg dose with a product-verification mark. If you want an NSF Certified for Sport product, Thorne Magnesium Bisglycinate is the same dose per capsule at $0.43. If price matters most, Vitamin Shoppe Magnesium Glycinate is $0.11 per 200 mg with no third-party mark; one tablet is 200 mg, so take one, not the two-tablet serving on the label.

How much magnesium glycinate should I take?

Read the Supplement Facts "Magnesium" row, which is elemental magnesium, and ignore any compound weight on the front. Adults get 310 to 420 mg a day from food plus supplements; the NIH sets 350 mg a day as the limit for supplemental magnesium in adults, above which loose stools become common. On the 149 glycinate labels we read, the median serving is 250 mg and 32.9% direct 400 mg or more, so check the serving size: 78.5% of labels need two or more capsules to reach the dose printed on the front.

Is magnesium glycinate better than citrate or oxide?

Better tolerated, similarly absorbed. In a crossover trial of US commercial products, oxide was about 4% absorbed while chloride, lactate and aspartate were significantly higher and equal to one another (Firoz 2001), and a randomized trial found citrate ahead of both oxide and an amino-acid chelate on some measures (Walker 2003). Glycinate's advantage is the bowel: citrate and oxide draw water into the gut and act as laxatives at a few hundred milligrams, glycinate generally does not, which is why it is the form people can take at bedtime for months. See glycinate vs citrate for the trial-by-trial comparison.

Why does the bottle say 400 mg but the capsule only has 100 mg?

Because the front label states the serving, and 78.5% of glycinate labels define a serving as two or more capsules. The median capsule on the shelf carries 111 mg of elemental magnesium, so a 400 mg dose is typically 4 capsules (400 divided by 111 is 3.6). Some labels quote the weight of magnesium bisglycinate instead of the magnesium in it; bisglycinate is roughly 14% magnesium by weight.

Is "buffered" magnesium glycinate real glycinate?

Often it is glycinate blended with magnesium oxide to raise the milligram number per capsule. On the 57 labels we read that are named glycinate, 19.3% list another magnesium form in the Supplement Facts row, and oxide is the usual partner. Oxide is the least absorbed form, so a buffered product delivers less than its number suggests. The forms row on the label, not the product name, tells you what you are buying.

Does magnesium glycinate help you sleep?

The evidence is modest. A 2021 meta-analysis of three trials in older adults with insomnia found magnesium shortened time to fall asleep by about 17 minutes on low-quality evidence (Mah 2021). The glycine half has its own small trial record for sleep quality (Bannai 2012). Take it as a plausible, low-risk aid for someone who is short on magnesium, not a sedative.

Related guides

Sources

  1. Firoz M, Graber M. “Bioavailability of US commercial magnesium preparations.” Magnes Res. 2001. PMID: 11794633
  2. Walker AF, et al. “Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study.” Magnes Res. 2003. PMID: 14596323
  3. Pardo MR, et al. “Bioavailability of magnesium food supplements: A systematic review.” Nutrition. 2021. PMID: 34111673
  4. Schuette SA, et al. “Bioavailability of magnesium diglycinate vs magnesium oxide in patients with ileal resection.” JPEN J Parenter Enteral Nutr. 1994. PMID: 7815675
  5. Mah J, Pitre T. “Oral magnesium supplementation for insomnia in older adults: a Systematic Review & Meta-Analysis.” BMC Complement Med Ther. 2021. PMID: 33865376
  6. Bannai M, Kawai N. “New therapeutic strategy for amino acid medicine: glycine improves the quality of sleep.” J Pharmacol Sci. 2012. PMID: 22293292
  7. Kieboom BCT, et al. “Thiazide but not loop diuretics is associated with hypomagnesaemia in the general population.” Pharmacoepidemiol Drug Saf. 2018. PMID: 30095199
  8. NIH Office of Dietary Supplements. Magnesium: Fact Sheet for Health Professionals (RDAs and the 350 mg supplemental upper limit). ods.od.nih.gov
  9. NIH Office of Dietary Supplements. Dietary Supplement Label Database. dsld.od.nih.gov