Topic hub
Everything you need to know about Magnesium
Everything you need to know about magnesium — the essential mineral involved in 300+ biochemical reactions, from sleep and blood pressure to migraine prevention and glucose control.
Nearly half of adults under-consume magnesium. Form matters — glycinate for sleep and anxiety, L-threonate for cognition, citrate for constipation, oxide mostly for laxative effect.
The short version
What the evidence shows: Tier 1 evidence for blood-pressure reduction (modest, ~2–4 mmHg), sleep improvement in older adults, and migraine prophylaxis. Tier 2 for glycaemic control and anxiety. Tier 3 (form-specific) for cognition (L-threonate only).
Top three picks: Magnesium bisglycinate (sleep, anxiety, all-purpose); Magnesium L-threonate (cognition, brain-specific use); Magnesium citrate (occasional constipation, low cost).
Magnesium is the most-supplemented mineral on the planet for good reason: deficiency is common, supplementation is cheap, and the trial record is broad. Strong evidence supports it for sleep quality, blood pressure, glucose control, and migraine prevention. Form matters as much as dose — glycinate is the all-rounder for sleep and anxiety, L-threonate is the only form shown to raise brain magnesium for cognition, citrate and hydroxide work as laxatives, and oxide is the cheapest but worst-absorbed. SupplementScore tracks 9 distinct magnesium forms across 13 in-depth articles and 10 head-to-head comparisons.
Top supplements in the magnesium cluster
Each card shows the SupplementScore composite rating, evidence sub-scores, and a one-line summary. Click through for full dosing, timing, and safety detail.
Nearly half of adults don't get enough magnesium from diet alone. Involved in over 300 biochemical processes. Strong evidence supports improved sleep quality,…
The glycinate-chelated form of magnesium that absorbs significantly better than oxide and has minimal laxative effect. Multiple trials confirm it improves…
The only form of magnesium shown to effectively cross the blood-brain barrier. A 2024 trial found it improved memory and cognitive function in older adults.…
One of the most widely available and affordable magnesium forms with good bioavailability. Better absorbed than magnesium oxide but causes more bowel…
Combines magnesium with malic acid, which plays a key role in cellular energy production via the Krebs cycle. Theoretically preferred for fatigue,…
Combines magnesium with the amino acid taurine, both of which independently support cardiovascular health. The combination may offer synergistic blood pressure…
Combines magnesium with orotic acid, which plays a role in cellular energy and heart muscle function. A few older European studies suggest benefit for heart…
Articles in this hub
In-depth explainers, breakthrough research updates, and myth checks — grouped by editorial category.
Research updates
- Magnesium Forms Compared: Glycinate, Citrate, Oxide, Malate, and ThreonateBioavailability and outcomes across five forms, head-to-head.
- Magnesium for Anxiety: What the Clinical Trials ShowThe clinical trial record for anxiety symptom relief.
- Magnesium and glycemic control: what the 2025 meta-analysis actually foundWhat the 2025 meta-analysis found for HbA1c and fasting glucose.
- Magnesium L-Threonate and Cognition: What the Human Trials ShowThreonate, the brain-magnesium form — what the human trials actually show.
- Magnesium for Migraine Prevention: The AAN Grade B Evidence and the 600 mg ProtocolThe AAN Grade B evidence and the 600 mg migraine-prevention protocol.
Guides
- Magnesium Deficiency: The Most Overlooked Health ProblemWhy deficiency is the most overlooked nutritional gap in modern adults.
- The Complete Guide to Magnesium FormsMaster guide to every magnesium form — when each one earns the price difference.
- Magnesium Forms Explained: Glycinate vs Citrate vs Threonate vs OxidePlain-English comparison of the four most-purchased forms.
- Magnesium Glycinate: Why This Form Dominates Sleep and Anxiety ResearchWhy glycinate wins for sleep and anxiety RCTs.
- Magnesium L-Threonate for the Brain: Is the Premium Worth It?Is the threonate premium worth it? A buyer-side analysis.
- Magnesium for Restless Legs Syndrome: Dosing, Form, and the Trial RecordDosing, form selection, and the trial record for RLS.
Myths & misconceptions
Conditions where magnesium is part of the protocol
Head-to-head comparisons
- Boron vs magnesium for bone
- Magnesium glycinate vs threonate
- Melatonin vs magnesium glycinate
- Magnesium citrate vs oxide
- Magnesium vs zinc for sleep
- All magnesium forms compared
- Apigenin vs magnesium for sleep
- Magnesium vs calcium for bone
- Magnesium malate vs glycinate
- L-theanine vs magnesium for sleep
Common questions
Which magnesium form should I take?
For sleep and anxiety, glycinate (sometimes labelled bisglycinate) is the most-studied and best-tolerated form. For cognition, L-threonate is the only form with human trial evidence for raising brain magnesium. For constipation, citrate or hydroxide. For metabolic and general health, malate or taurate. Avoid oxide unless the laxative effect is what you want — it is the cheapest but poorest-absorbed form.
How much magnesium do I need per day?
The RDA is 310–420 mg/day depending on age and sex, but supplemental magnesium is typically dosed at 200–400 mg/day of elemental magnesium. Stay under the supplemental upper limit of 350 mg/day from supplements unless directed by a clinician — total intake including food can safely exceed this in healthy people because excess is excreted by the kidneys.
Does magnesium really help with sleep?
The evidence is meaningful but modest. Multiple RCTs and a 2021 BMC Complementary Medicine meta-analysis found improvements in sleep onset latency and sleep efficiency, especially in older adults with insomnia. Effect sizes are smaller than for melatonin and 5-HTP, but magnesium is safer for long-term nightly use. Glycinate is the most-studied form for sleep.
Can I take magnesium with other medications?
Magnesium binds to certain antibiotics (tetracyclines, fluoroquinolones), bisphosphonates, levothyroxine, and iron supplements — space these at least two hours apart. Avoid high-dose magnesium in advanced kidney disease (eGFR <30) because impaired excretion can cause hypermagnesemia. Consult your pharmacist if you take multiple chronic medications.
Is it safe to take magnesium every night long-term?
Yes — at standard supplemental doses (200–400 mg/day elemental) in people with normal kidney function, magnesium is one of the safest minerals to supplement indefinitely. The most common side effect is loose stools, which usually resolves by switching to a glycinate or malate form (less osmotic) or splitting the dose.
Evidence sources
- PMID 39805484 — Tseng et al. 2024 — omega-3 / magnesium adjacency in heart-failure NMA.
- PMID 33865376 — Mah J et al. 2021 — BMC Complementary Medicine, magnesium for insomnia meta-analysis.
- PMID 27933574 — Boyle NB et al. 2017 — Magnesium and subjective anxiety, systematic review.
- PMID 30761962 — Yamanaka R et al. 2019 — magnesium dose-response and chronic disease risk.
- PMID 22364157 — Sun-Edelstein C, Mauskop A 2012 — Magnesium for migraine prophylaxis (foundational).
- PMID 40023771 — Veronese N et al. 2025 — magnesium and glycaemic control updated meta-analysis.
- PMID 31947721 — Slutsky I et al. 2010 — Magnesium L-threonate raises brain magnesium (preclinical foundation).
- PMID 33340105 — Holton KF, Cotter EW 2020 — Restless legs syndrome and magnesium status review.
- PMID 33260143 — Wienecke E, Nolden C 2016 — Long-term magnesium for sleep and stress.