What is elemental magnesium and why does it matter on supplement labels?

Elemental magnesium is the actual magnesium mineral content per dose, not the weight of the whole compound. Magnesium glycinate is approximately 10 to 14 percent elemental magnesium by weight. A product labelled as 500 mg magnesium glycinate may deliver only around 50 to 70 mg of actual magnesium. Always compare products by elemental magnesium per serving.

Is magnesium glycinate better than citrate for sleep?

For sleep specifically, magnesium glycinate has a stronger case because the glycine carrier molecule has its own published RCT evidence for improving sleep quality, reducing sleep latency, and reducing daytime fatigue — independent of magnesium. Citrate provides only the magnesium component. Both forms should be compared by elemental magnesium per serving, not compound weight. Glycinate is also generally better tolerated at higher doses.

Magnesium capsules and water glass representing magnesium for sleep in Ireland

Reference page (Ireland) · Public education · Not medical advice · 7 min read

Magnesium for Sleep in Ireland: Does Magnesium Glycinate Work? Evidence, Dosage, and the Glycine Advantage

Q: Does magnesium glycinate actually help with sleep?

Published RCT evidence shows magnesium supplementation improved sleep onset latency and early-morning awakenings in adults with insomnia symptoms (Mah & Pitre, 2024, BMC Complementary Medicine, PMC12032433). Magnesium glycinate has a stronger theoretical and evidence-based case than other forms because the glycine carrier molecule has independent sleep RCT evidence, including Bannai et al. (2012) and Yamadera et al. (2007), showing reduced sleep latency and improved sleep quality scores in human trials.

Q: What dose of magnesium is recommended in Ireland?

HSE Ireland guidance lists typical daily needs as 300 mg/day for men and 270 mg/day for women aged 19 to 64. More than 400 mg/day from supplements can cause diarrhoea. 400 mg/day or less from supplements is unlikely to cause harm for most adults. Always check the elemental magnesium per serving on the label, not the compound weight.

Q: What are the EFSA-authorised health claims for magnesium in Ireland?

Under EU Commission Regulation 432/2012, authorised health claims for magnesium include: Magnesium contributes to normal psychological function; Magnesium contributes to the normal functioning of the nervous system; Magnesium contributes to the reduction of tiredness and fatigue; and Magnesium contributes to normal muscle function. These apply when the product meets the minimum magnesium content threshold in Regulation 1924/2006.

Most pages about magnesium and sleep mix bold claims with weak sourcing. This guide does the opposite: we give you the named studies, the exact EFSA-authorised claims you are legally allowed to rely on, the missing science about why glycinate specifically has a stronger sleep case than other forms, and an Ireland-first dosing framework anchored to HSE guidance. No hype. Just evidence.

✏️ Quick answers — skip here if you are in a hurry

📑 Does magnesium help sleep? A 2024 systematic review and meta-analysis (Mah & Pitre, BMC Complementary Medicine, PMC12032433) found magnesium supplementation reduced sleep onset latency and early-morning awakenings. Effect sizes were moderate. This is real signal, not magic.
💡 Why is glycinate different from other forms for sleep? It is the only form where the carrier molecule itself — glycine — has independent published RCT evidence for improving sleep quality. More on this below. This is the most important thing most sleep supplement pages never mention.
✅ What can be legally claimed in Ireland? Under EU Regulation 1924/2006, magnesium has authorised claims including: "Magnesium contributes to normal psychological function" and "Magnesium contributes to the normal functioning of the nervous system." These are not marketing. They are law.
📋 What dose is safe in Ireland? HSE guidance: 300 mg/day men, 270 mg/day women (ages 19–64). More than 400 mg/day from supplements can cause diarrhoea. 400 mg or less is unlikely to cause harm for most adults. HSE source →
🏴 What matters most on labels? Elemental magnesium per serving — not compound weight. A 500 mg magnesium glycinate tablet may only contain around 50 mg of elemental magnesium. These numbers are not the same thing.

📝 In-Depth Guide

Magnesium Glycinate Ireland: Benefits, Dosage and How to Choose

The pillar guide to magnesium glycinate in Ireland — covering label decoding, elemental magnesium explained, HSE dose reference, and how to choose between forms.

Read the full guide →

1. The EFSA-Authorised Claims for Magnesium — What You Are Legally Allowed to Say in Ireland

Before the research — because this matters for how you evaluate every magnesium product you read about. Under EU Commission Regulation 432/2012, the following health claims for magnesium are legally authorised across Ireland and the EU. These are not marketing slogans. They are approved statements based on EFSA-reviewed scientific evidence, and they can be stated on food supplement labels and in product communications:

Authorised EFSA Claim	Why It Matters for Sleep
Magnesium contributes to normal psychological function	Psychological function includes mood regulation and mental relaxation — processes directly relevant to sleep onset
Magnesium contributes to the normal functioning of the nervous system	The nervous system governs the transition between wakefulness and sleep; neurotransmission balance is central to sleep architecture
Magnesium contributes to the reduction of tiredness and fatigue	Directly relevant to the daytime consequences of poor sleep quality
Magnesium contributes to normal muscle function	Muscle relaxation is a prerequisite for physical sleep onset — tension and cramping are common sleep disruptors

Source: Commission Regulation (EU) No 432/2012 of 16 May 2012 establishing a list of permitted health claims made on foods. Claims apply when the food is at least a source of magnesium as defined in Annex to Regulation (EC) No 1924/2006.

2. What Published Research Shows About Magnesium and Sleep

Here is the honest, evidence-based position: magnesium supplementation has been associated with improvements in measurable sleep parameters in published human trials, particularly in adults with suboptimal magnesium status or insomnia symptoms. The effect is real but not universal, and results vary by study design, population, dose, duration, and the form used.

📊 Randomised controlled trial — older adults with insomnia

Abbasi B et al. (2012), Journal of Research in Medical Sciences (PubMed ID: 23853635). A double-blind, placebo-controlled RCT in 46 older adults with primary insomnia. The magnesium group showed significant improvements in sleep time, sleep efficiency, early morning awakenings, serum renin, melatonin, and serum cortisol versus placebo. This is a single trial in an older population — not a universal outcome guarantee — but it is properly conducted RCT evidence.

📊 2024 Systematic review and meta-analysis — pooled RCT data

Mah J & Pitre T (2024), BMC Complementary Medicine and Therapies (PMC12032433). A systematic review and meta-analysis of randomised controlled trials on magnesium supplementation and sleep outcomes. The pooled data showed significant improvements in sleep onset latency and early-morning awakenings. Results across other sleep parameters were mixed, reflecting genuine heterogeneity in the trial populations and study designs. The authors note that magnesium supplementation appears beneficial particularly in populations with insomnia or suboptimal magnesium status.

⚠️ Honest caveat: The European average dietary intake of magnesium ranges from 250–300 mg/day in women and 320–440 mg/day in men (EFSA, 2015, EFSA Journal 13(7):4186). Where dietary intake is already adequate, the incremental benefit of supplementation may be smaller. Magnesium supplementation is not a sedative and is not a substitute for addressing underlying causes of poor sleep.

3. The Glycine Argument — Why Magnesium Glycinate Has a Stronger Sleep Case Than Other Forms

This is the section almost no supplement page covers. It is the single strongest argument for choosing glycinate over other magnesium forms if sleep is your goal — and it has nothing to do with magnesium absorption rates.

Magnesium glycinate is magnesium bound to glycine — a non-essential amino acid. The glycine component is not inert. It has its own independent published research record on sleep quality, separate from magnesium entirely.

The Glycine Sleep Mechanism — Published Evidence

Published research has documented that glycine crosses the blood-brain barrier and acts on NMDA receptors in the suprachiasmatic nucleus (SCN) — the brain's master circadian clock. This action produces peripheral vasodilation and a measurable decrease in core body temperature. Core body temperature drop is one of the physiological prerequisites for sleep onset. By accelerating this drop, glycine has been shown in human trials to shorten the time to sleep onset and improve sleep quality.

📊 RCT: Yamadera et al. (2007) — Sleep and Biological Rhythms

In a double-blind crossover trial, participants with self-reported poor sleep who ingested glycine before bedtime showed significant improvements in sleep quality (Pittsburgh Sleep Quality Index), sleep efficacy, and shortened PSG latency to both sleep onset and slow-wave sleep. Sleep architecture was not negatively altered.

📊 RCT: Bannai et al. (2012) — Frontiers in Neurology (PubMed ID: 22529837)

A randomised crossover trial in 20 healthy males with restricted sleep. Three grams of glycine taken 30 minutes before bedtime significantly reduced daytime sleepiness and fatigue versus placebo. Reaction time performance was also significantly improved on the Psychomotor Vigilance Test. The mechanism identified was glycine-mediated core body temperature reduction via SCN NMDA receptor activation.

📊 Mechanistic study: Kawai et al. (2015) — Neuropsychopharmacology (PMC4397399)

This study confirmed the site of action: oral glycine crosses the blood-brain barrier by passive diffusion, acts on NMDA receptors in the SCN, promotes peripheral vasodilation, and shortens NREM sleep latency in an acute sleep disturbance model. This is the mechanistic confirmation of the human trial findings.

💡 What this means practically: When you take magnesium glycinate, you are getting two compounds — magnesium and glycine — both of which have independent published evidence relevant to sleep. No other common magnesium form (citrate, oxide, malate, threonate) provides this dual-compound sleep mechanism. This is the scientific case for glycinate specifically. It is not marketing. It is published biology.

4. Magnesium Glycinate vs Citrate for Sleep — The Honest Comparison

The practical difference between forms is not "glycinate equals sleep, citrate equals no sleep." It is more nuanced than that — and elemental magnesium content matters more than form in most cases.

Factor	Glycinate / Bisglycinate	Citrate
Sleep-specific case	Stronger — glycine component has independent sleep RCT evidence	Magnesium only — no sleep-specific carrier molecule
Tolerance	Generally well tolerated — chelated form less likely to cause loose stools at typical doses	Can trigger loose stools at higher doses — relevant at the upper end of supplemental intake
Elemental Mg %	Lower (~10–14%) — requires larger compound dose for same elemental magnesium	Higher (~16%) — more elemental magnesium per gram of compound
Label check	Always read elemental Mg per serving — not compound weight	Always read elemental Mg per serving — not compound weight

For the full form-by-form comparison including absorption, bioavailability research, and label reading guide: Magnesium glycinate vs citrate Ireland — full guide →

5. Ireland-First Dosing Framework — HSE Reference

🏴 HSE Ireland Reference — Magnesium

Typical daily needs: 300 mg/day for men, 270 mg/day for women (ages 19–64)
More than 400 mg/day from supplements can cause diarrhoea
400 mg/day or less from supplements is unlikely to cause harm for most adults
Source: HSE Vitamins and Minerals (Others) →

Practical steps for Irish adults:

1️⃣

Start low, increase slowly. Begin at the lower end of your target dose and increase over 7–14 days. This reduces the risk of gastrointestinal discomfort as your body adjusts.

2️⃣

Read for elemental magnesium — always. A label saying "500 mg magnesium glycinate" does not mean 500 mg of magnesium. Magnesium glycinate is approximately 10–14% elemental magnesium. That 500 mg tablet likely delivers around 50–70 mg of actual magnesium. Compare products on elemental mg per serving, not compound weight.

3️⃣

Evening timing is common — but not proven superior. Many people take magnesium before bed because it fits the glycine sleep mechanism research (glycine ideally 30 minutes before bedtime). Evening timing also simply fits a routine. If it causes stomach discomfort, take with food.

4️⃣

Loose stools mean reduce the dose. This is the most common side effect at higher supplemental magnesium intakes and is specifically flagged in HSE public guidance. It is not dangerous but it means you have exceeded your tolerance threshold. Reduce the dose rather than stopping entirely.

6. What to Buy in Ireland — Verified Format Reference

If you want to compare products by form, elemental magnesium content, and label clarity: Magnesium collection — Probiotic.ie →

Featured Glycinate Option

NOW Foods Magnesium Bisglycinate / Glycinate — 180 Tablets

Chelated bisglycinate format. Clear elemental magnesium labelling. Suitable for those who want the glycine dual-mechanism form for evening use. One of the most transparently labelled glycinate options available in Ireland.

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📚 The full Ireland magnesium guide cluster

Magnesium Glycinate Ireland: Guide, Benefits, Dosage and Labels →

The pillar page: HSE dosing, 400 mg/day supplement note, and label decoding.

Magnesium Bisglycinate Ireland: Benefits, Dosage and How It Compares →

Bisglycinate in plain English: how to compare formats and avoid label mistakes.

Magnesium Glycinate vs Citrate Ireland: What Matters on Labels →

The comparison guide: elemental magnesium, tolerance, and how to choose.

7. Frequently Asked Questions

Does magnesium glycinate actually help with sleep? +

Published RCT evidence shows that magnesium supplementation improved measurable sleep parameters — including sleep onset latency and early-morning awakenings — in adults with insomnia symptoms or suboptimal magnesium status (Mah & Pitre, 2024, BMC Complementary Medicine). Glycinate specifically has a stronger theoretical and evidence-based case than other forms because the glycine carrier molecule has its own independent sleep RCT evidence, including published human trials showing reduced sleep latency and improved sleep quality scores.

What is the glycine sleep mechanism and why does it matter? +

Glycine crosses the blood-brain barrier and acts on NMDA receptors in the suprachiasmatic nucleus — the brain's master circadian clock. This action promotes peripheral vasodilation and accelerates the core body temperature drop that is required for sleep onset. Published human RCTs by Yamadera et al. (2007) and Bannai et al. (2012) documented that glycine taken before bedtime shortened sleep latency, improved sleep quality scores, and reduced daytime fatigue. This mechanism is independent of magnesium and only applies to magnesium glycinate (bisglycinate) — not other magnesium forms.

What dose of magnesium is recommended in Ireland? +

HSE guidance lists typical daily needs as 300 mg/day for men and 270 mg/day for women aged 19–64. The HSE specifically notes that more than 400 mg/day from supplements can cause diarrhoea, and that 400 mg/day or less from supplements is unlikely to cause harm for most adults. Always check the elemental magnesium per serving on the label — not the compound weight — to know what you are actually taking.

What is elemental magnesium and why does it matter on labels? +

Elemental magnesium is the actual amount of magnesium mineral you receive per dose — not the weight of the whole compound (magnesium bound to glycine, citric acid, or other carrier molecules). Magnesium glycinate is approximately 10–14% elemental magnesium by weight. So a product labelled as 500 mg magnesium glycinate may only deliver around 50–70 mg of actual magnesium. Always compare products by elemental magnesium per serving, not compound weight.

Is it safe to take magnesium supplements every night? +

For most healthy adults, daily magnesium supplementation at or below 400 mg of elemental magnesium per day from supplements is unlikely to cause harm per HSE guidance. Magnesium has a well-established safety profile at standard supplemental doses. If you have kidney disease, are on medication, or are pregnant, consult your GP or pharmacist before starting any supplement. The most common side effect at higher doses is diarrhoea — reduce the dose if this occurs.

What are the EFSA-authorised health claims for magnesium in Ireland? +

Under EU Commission Regulation 432/2012, the following claims are legally authorised for magnesium: (1) Magnesium contributes to normal psychological function; (2) Magnesium contributes to the normal functioning of the nervous system; (3) Magnesium contributes to the reduction of tiredness and fatigue; (4) Magnesium contributes to normal muscle function; (5) Magnesium contributes to the maintenance of normal bones and teeth. These apply when the product meets the minimum magnesium content threshold defined in the Annex to Regulation (EC) No 1924/2006.

Should I take magnesium at night or in the morning? +

There is no strong clinical evidence that evening timing is definitively superior for magnesium absorption. However, given the glycine sleep mechanism research — which found the most benefit from glycine taken 30 minutes before bedtime — evening timing is a reasonable and consistent choice for magnesium glycinate specifically. If the supplement causes stomach discomfort, take it with food rather than on an empty stomach.

8. Safety Notes

⚠️ Who should check with a clinician before supplementing

Kidney disease: the kidneys regulate magnesium excretion — impaired kidney function increases the risk of magnesium accumulation. Speak with your GP first.
Medication: magnesium can interact with certain antibiotics, diuretics, and medications used for osteoporosis. Check with your pharmacist if you take regular medication.
Pregnancy: consult your GP or midwife before starting any new supplement during pregnancy.
Do not chase high doses: more than 400 mg/day from supplements can cause diarrhoea per HSE guidance. Higher is not better.

Note: This is educational content. It is not medical advice. If you have persistent sleep problems, a medical condition, or take regular medication, speak with your GP or pharmacist before starting any supplement.

In Ireland, food supplements must not be marketed as preventing, treating, or curing disease. FSAI guidance →

References

[Ref A] Abbasi B et al. (2012). "The effect of magnesium supplementation on primary insomnia in elderly: A double-blind placebo-controlled clinical trial." Journal of Research in Medical Sciences. PubMed 23853635 →

[Ref B] Mah J & Pitre T (2024). Systematic review and meta-analysis: magnesium supplementation and sleep outcomes, including sleep onset latency and early-morning awakenings. BMC Complementary Medicine and Therapies. PMC12032433 →

[Ref C] Yamadera W et al. (2007). "Glycine ingestion improves subjective sleep quality in human volunteers, correlating with polysomnographic changes." Sleep and Biological Rhythms 5(2):126–131.

[Ref D] Bannai M et al. (2012). "The Effects of Glycine on Subjective Daytime Performance in Partially Sleep-Restricted Healthy Volunteers." Frontiers in Neurology 3:61. PubMed 22529837 →

[Ref E] Kawai N et al. (2015). "The Sleep-Promoting and Hypothermic Effects of Glycine are Mediated by NMDA Receptors in the Suprachiasmatic Nucleus." Neuropsychopharmacology 40(6):1405–16. PMC4397399 →

[Ref F] EFSA NDA Panel (2015). Scientific Opinion on Dietary Reference Values for magnesium. EFSA Journal 13(7):4186. Adequate Intake set at 350 mg/day men, 300 mg/day women. EFSA Journal →

[Ref G] Commission Regulation (EU) No 432/2012 of 16 May 2012 — EU Register of authorised health claims for magnesium. EUR-Lex →

[Ref H] HSE Ireland. Vitamins and minerals — Others (magnesium daily needs and supplement tolerance note). HSE →

[Ref I] Food Safety Authority of Ireland (FSAI). Food supplements guidance — compliance rules for nutrition and health claims in Ireland. FSAI →

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