Magnesium Glycinate Statistics & Facts
Magnesium is essential and most people under-eat it — but the supplement claims run well ahead of the trials. Three findings anchor the honest picture:
Magnesium in numbers
Safety headline: well tolerated at the clinical 200–400 mg elemental dose — the dose-limiting effect is loose stools above ~350 mg of supplemental magnesium, and the one hard contraindication is significant kidney disease, where impaired clearance can cause dangerous hypermagnesemia. it can also bind some antibiotics and add to blood-pressure medication[18,17].
Magnesium, scored across goals
The fact that matters most for a decision: how strongly magnesium actually moves each goal, on our SAC Efficacy Score™ — the same 0–10 score we rank every substance by (weighted 45% effect size, 40% evidence strength, 15% reliability). Tap a goal to see the full ranking against everything else.
The Magnesium Glycinate market in numbers
Our independent analysis of 7 magnesium glycinate products, scored on three proprietary indices — the SAC Product Score™, Transparency Index™, and real Cost-Per-Effective-Dose™. Updated July 2026.
| # | Product | SAC Product Score™ | TXI™ | CPED™ | |
|---|---|---|---|---|---|
| 1 | Pure Encapsulations Magnesium (Glycinate)Capsule | 9.2 | 75 | $0.44 | Most transparent |
| 2 | Doctor's Best High Absorption Magnesium Glycinate LysinateTablet | 9.0 | 40 | $0.15 | |
| 3 | Thorne Magnesium BisglycinatePowder | 8.7 | 70 | $0.58 | |
| 4 | Nutricost Magnesium BisglycinateCapsule | 8.4 | 20 | $0.10 | Best value |
| 5 | Klean Athlete Klean MagnesiumCapsule | 8.1 | 50 | $0.50 | Under-dosed |
| 6 | NOW Foods Magnesium GlycinateTablet | 8.0 | 40 | $0.18 | |
| 7 | Nested Naturals Magnesium GlycinateCapsule | 7.9 | 0 | $0.41 | Under-dosed |
Methodology. SAC Product Score™ blends our editorial rating (RCT quality, dose, safety, value) 50/50 with community ratings. Transparency Index™ (0-100) = third-party certification (0-50) + public batch COA (0-30) + dose honesty (0-20). Cost-Per-Effective-Dose™ is the real price of one clinical dose, not one marketed "serving". Free to cite with attribution to Super Achiever.
Bottom line: which magnesium to actually buy
Two rules cut through the whole category: buy a chelated form (glycinate), never oxide, and match the form to your goal. The table above sorts by raw SAC Product Score™, so the practitioner-grade option (Pure Encapsulations, 9.2) sits on top. But the best decision for most people balances quality with cost per dose:
- Best overall — Doctor's Best High Absorption (9.0).A true chelated bisglycinate-lysinate at 200 mg elemental, at roughly $0.15 a dose— the quality-and-value sweet spot. What we'd put in most people's hands.
- Best premium — Pure Encapsulations Magnesium Glycinate (9.2). The top raw score: practitioner-grade, hypoallergenic, spotless label — you pay more (~$0.44/dose) for the cleanest sourcing.
- Best budget — Nutricost Magnesium Bisglycinate (8.4). The same chelated form at about $0.10 a dose — the cheapest honest glycinate on the board.
- Straight from us — Super Achiever Magnesium Glycinate. Our own bisglycinate at a real dose, shown clearly labelled at the top of the table and scored on the same 50/50 criteria — no oxide filler.
The data — free to share & cite
The effects with the strongest evidence, by the numbers — and framed honestly, including where the benefit is modest or population-specific. For the full breakdown see magnesium benefits and side effects.
Sleep: falls-asleep-faster is real; sleep-longer is not proven
change vs placebo in older adults with insomnia · magnesium helped people fall asleep ~17 min faster — but the extra total sleep time was NOT statistically significant, and the evidence was graded low quality
Blood pressure: small on average, real in the right people
reduction in systolic BP vs placebo · the whole-population drop is modest — the meaningful reductions are in people already on BP medication or who are magnesium-deficient; in people with normal BP it was not significant
Migraine: fewer attacks — at a high, specific dose
reduction in monthly migraine attack frequency over 12 weeks (weeks 9–12 vs baseline) · 600 mg/day of trimagnesium dicitrate — a dose above the 350 mg supplemental limit, so loose stools are expected
The main side effect is your gut — and it's dose-dependent
adverse events at the high 600 mg/day migraine dose · at the usual 200–400 mg elemental dose these are much less common, and they depend heavily on the form (oxide and citrate are the most laxative)
How long until it works
typical time to a felt effect — magnesium sets the stage over weeks; it is not a same-day sedative
Forms compared — the decision that matters most
| Form | The pick? | What the evidence says | Source |
|---|---|---|---|
| Glycinate (bisglycinate) | Default | The default. Well-absorbed and the gentlest on the gut, and the bound glycine adds a mild calming effect — the right all-round form for sleep, stress and daily repletion. | [16] |
| L-Threonate (Magtein) | Situational | Situational. Designed to raise brain magnesium for cognition + sleep — but the famous memory result is in RATS (Slutsky 2010); human trials are small and new. Costlier; a sister form, not a must. | [15] |
| Citrate | Situational | Situational. Well-absorbed and cheap, but laxative at clinical doses — the right pick if you also want constipation relief, the wrong one for athletes or anyone prone to loose stools. | [10] |
| Oxide | Skip | Skip. Only ~4% is absorbed — a 500 mg oxide pill delivers ~20 mg of usable magnesium. It is the cheapest, most-marketed form and the wrong one for sleep or neurological goals. | [9] |
Myths vs. facts
| The myth | What the evidence shows | Source |
|---|---|---|
| Magnesium cures muscle cramps | The best evidence says no. A Cochrane review concluded magnesium is unlikely to meaningfully prevent idiopathic or older-adult leg cramps — the pooled effect was not statistically significant. It is the single most-marketed magnesium claim and the least supported. | [8] |
| Any magnesium works — they're all the same | Form is everything. Magnesium oxide, the cheapest and most common form, is only about 4% absorbed; glycinate, citrate and L-threonate are far better absorbed. 'Magnesium' unqualified — or oxide — is largely the wrong product for sleep and neurological goals. | [9,10] |
| Magnesium is a knockout sleeping pill | It isn't a sedative. In the older-adult meta-analysis it helped people fall asleep about 17 minutes faster but did NOT significantly increase total sleep time, and the evidence was low quality. It sets the stage for sleep over 1–2 weeks rather than knocking you out. | [1] |
| Magnesium lowers everyone's blood pressure a lot | The average drop is small — about 3/2 mmHg. The meaningful reductions (6–8 mmHg systolic) are in people already on blood-pressure medication or who are magnesium-deficient; in people with normal blood pressure the effect wasn't significant. | [4] |
| More magnesium is always better | Above ~350 mg/day of supplemental magnesium the main extra effect is loose stools (an osmotic laxative effect). The therapeutic migraine dose (600 mg) is used knowing that trade-off. Magnesium from food has no upper limit — healthy kidneys excrete the excess. | [18,5] |
| L-threonate is proven to boost memory in people | The headline memory result is from rats (Slutsky 2010, in Neuron). Human evidence is small and early. It's a mechanistically promising brain-targeted form — promising, not proven, and not a reason to pay 3× for it unless cognition is the specific goal. | [15] |
| Magnesium fixes blood sugar | It modestly improves insulin sensitivity (HOMA-IR) and fasting glucose, mainly in people who are diabetic or magnesium-deficient; the effect on long-term HbA1c is borderline. A helpful adjunct in those groups — not a general blood-sugar cure. | [14] |
Go deeper
Frequently asked questions
What is magnesium glycinate best for?
Sleep quality and everyday magnesium repletion, with a gentler stomach than other forms. In older adults with insomnia, magnesium helped people fall asleep about 17 minutes faster than placebo (though it did not significantly lengthen total sleep, and the evidence was low quality). It also modestly lowers blood pressure — mostly in people already on BP medication or who are deficient — and is one of the better-supported migraine-prevention supplements at a higher dose.
Which form of magnesium is best — glycinate, citrate, threonate or oxide?
For sleep, stress and daily repletion, glycinate (bisglycinate) is the best all-round form: well-absorbed and gentle, with a mild calming effect from its bound glycine. Citrate is well-absorbed and cheap but laxative — good if you also want constipation relief. L-threonate is a brain-targeted form for cognition, but its memory evidence is largely from animal studies, so it's a situational upgrade. Avoid oxide: only about 4% is absorbed, so a 500 mg oxide pill delivers roughly 20 mg of usable magnesium.
Does magnesium actually help muscle cramps?
Probably not for the most common kind. A Cochrane systematic review concluded that magnesium is unlikely to meaningfully prevent idiopathic or older-adult leg cramps — the pooled effect wasn't statistically significant. There's a little more (still inconsistent) signal for pregnancy-associated cramps. It's the most heavily marketed magnesium claim and the least supported by trials.
How much magnesium glycinate should I take, and when?
The clinical range is 200–400 mg of elemental magnesium per day. Take it in the evening for sleep, or split morning and evening if you're chasing recovery and HRV. Note the label distinction: '500 mg magnesium glycinate' is the chelate weight, while the elemental magnesium it delivers is smaller — read the panel for the elemental figure. Stay at or below about 350 mg of supplemental elemental magnesium unless a clinician directs otherwise, since higher doses mainly add loose stools.
How long until magnesium glycinate works?
Most people feel a subtle evening relaxation within 2–3 days. Sleep depth improves over 1–2 weeks; HRV and recovery benefits show up around 3–4 weeks; full body-pool repletion takes 4–8 weeks. If nothing has shifted by week 4 on a real glycinate dose, double-check you're not actually taking oxide.
Who should not take magnesium supplements?
Anyone with significant kidney disease should not supplement magnesium without a nephrologist, because impaired clearance can cause dangerous hypermagnesemia. Separate magnesium from certain antibiotics (tetracyclines and quinolones) and from bisphosphonates by a few hours, since it reduces their absorption, and coordinate with your doctor if you take blood-pressure medication or sedatives, as the effects can be additive. In pregnancy, staying near the RDA is fine but supplementing above it needs obstetric oversight.
Sources
Every research figure links to one of these. All PMIDs were verified to resolve to the correct paper on PubMed.
- Mah J, Pitre T. Oral magnesium supplementation for insomnia in older adults: a systematic review & meta-analysis. BMC Complement Med Ther. 2021;21(1):125. PMID 33865376
- Abbasi B, Kimiagar M, Sadeghniiat K, Shirazi MM, Hedayati M, Rashidkhani B. The effect of magnesium supplementation on primary insomnia in elderly: a double-blind placebo-controlled clinical trial. J Res Med Sci. 2012;17(12):1161–1169. PMID 23853635
- Held K, Antonijevic IA, Künzel H, et al. Oral Mg2+ supplementation reverses age-related neuroendocrine and sleep EEG changes in humans. Pharmacopsychiatry. 2002;35(4):135–143. PMID 12163983
- Argeros Z, Xu X, Bhandari B, Harris K, Touyz RM, Schutte AE. Magnesium supplementation and blood pressure: a systematic review and meta-analysis of randomized controlled trials. Hypertension. 2025;82(11):1844–1856. PMID 41000008
- Peikert A, Wilimzig C, Köhne-Volland R. Prophylaxis of migraine with oral magnesium: results from a prospective, multi-center, placebo-controlled and double-blind randomized study. Cephalalgia. 1996;16(4):257–263. PMID 8792038
- Holland S, Silberstein SD, Freitag F, et al. Evidence-based guideline update: NSAIDs and other complementary treatments for episodic migraine prevention in adults (AAN/AHS). Neurology. 2012;78(17):1346–1353. PMID 22529203
- von Luckner A, Riederer F. Magnesium in migraine prophylaxis — is there an evidence-based rationale? A systematic review. Headache. 2018;58(2):199–209. PMID 29131326
- Garrison SR, Korownyk CS, Kolber MR, et al. Magnesium for skeletal muscle cramps. Cochrane Database Syst Rev. 2020;9(9):CD009402. PMID 32956536
- Firoz M, Graber M. Bioavailability of US commercial magnesium preparations. Magnes Res. 2001;14(4):257–262. PMID 11794633
- Walker AF, Marakis G, Christie S, Byng M. Mg citrate found more bioavailable than other Mg preparations in a randomised, double-blind study. Magnes Res. 2003;16(3):183–191. PMID 14596323
- Blancquaert L, Vervaet C, Derave W. Predicting and testing bioavailability of magnesium supplements. Nutrients. 2019;11(7):1663. PMID 31330811
- Boyle NB, Lawton C, Dye L. The effects of magnesium supplementation on subjective anxiety and stress — a systematic review. Nutrients. 2017;9(5):429. PMID 28445426
- Wienecke E, Nolden C. Long-term HRV analysis shows stress reduction by magnesium intake. MMW Fortschr Med. 2016;158(Suppl 6):12–16. PMID 27933574
- Simental-Mendía LE, Sahebkar A, Rodríguez-Morán M, Guerrero-Romero F. A systematic review and meta-analysis of randomized controlled trials on the effects of magnesium supplementation on insulin sensitivity and glucose control. Pharmacol Res. 2016;111:272–282. PMID 27329332
- Slutsky I, Abumaria N, Wu LJ, et al. Enhancement of learning and memory by elevating brain magnesium. Neuron. 2010;65(2):165–177. PMID 20152124
- Bannai M, Kawai N, Ono K, Nakahara K, Murakami N. The effects of glycine on subjective daytime performance in partially sleep-restricted healthy volunteers. Front Neurol. 2012;3:61. PMID 22529837
- Jahnen-Dechent W, Ketteler M. Magnesium basics. Clin Kidney J. 2012;5(Suppl 1):i3–i14. PMID 26069819
- Magnesium — Fact Sheet for Health Professionals. NIH Office of Dietary Supplements. Reference
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Super Achiever Club. (2026). Magnesium Glycinate Statistics & Facts 2026: The Complete Data Report. Retrieved from https://super-achiever.com/magnesium-glycinate-statistics<a href="https://super-achiever.com/magnesium-glycinate-statistics"><img src="https://super-achiever.com/charts/magnesium-glycinate/cost-per-dose.svg" alt="Magnesium cost per clinical elemental dose across products — Super Achiever Club" width="540" loading="lazy"></a>
<p><a href="https://super-achiever.com/magnesium-glycinate-statistics">Data: Magnesium Glycinate Statistics & Facts 2026: The Complete Data Report — Super Achiever Club</a></p>