Magnesium Types: Which Ones Do What

Magnesium is involved in hundreds of processes in the body — energy production, muscle and nerve function, blood sugar regulation, and sleep. However, most people run into the same issue: they buy “magnesium” without realising that different forms behave differently.

Pick the right type and magnesium can noticeably improve sleep quality, reduce muscle tension, support regular digestion, and increase stress resilience. Pick the wrong type and you might feel nothing — or spend an evening regretting it (hello, laxative effect).

In this guide, you’ll learn:

• the main magnesium types and what each one is best for
• which forms are most useful for sleep and calming the nervous system
• which forms support digestion, muscle recovery, and energy
• how to dose safely (and what “elemental magnesium” actually means)

1) The simple explanation

There’s no single “best” magnesium. Each type is magnesium bound to a different compound (glycine, citrate, malate, etc.). That compound changes:

• how well it’s absorbed
• where it acts (brain vs gut vs muscle)
• how likely it is to cause digestive side effects

If your goal is sleep and calm, you want a form that’s gentle on the gut and supports relaxation. If your goal is constipation relief, you want a form that draws water into the intestines.

2) Elemental magnesium (the label trick)

This is the #1 reason people under-dose or over-dose.

“Elemental magnesium” is the actual amount of magnesium your body can use. The capsule weight is often much higher because it includes the compound it’s bound to.

Rule of thumb: always look for “elemental magnesium” on the label (or in the supplement facts). If it doesn’t list elemental magnesium, that’s a red flag.

3) How much magnesium do you actually need?

In the UK, the NHS reference intake (RNI) is:

• 300 mg/day for men (19–64)
• 270 mg/day for women (19–64)

(That’s total magnesium from food + supplements.)

From a supplement perspective, a common useful range is 100–300 mg/day of elemental magnesium, depending on diet and goal.

Important safety note: many authorities set a tolerable upper limit of 350 mg/day of magnesium from supplements (not from food), mainly to avoid diarrhoea and GI side effects.

For baseline figures, see: NHS magnesium guidance and NIH ODS magnesium fact sheet.

4) Magnesium types: what each does

Use this section like a menu. Start with your goal, then choose the form that best matches it.

Magnesium glycinate (bisglycinate) — best for sleep & calm

Bound to glycine, which is naturally calming. This is often the best “first magnesium” because it’s well tolerated and broadly useful.

• Best for: sleep quality, relaxation, stress, muscle tension
• Notes: gentle on the stomach; good evening option

Magnesium L-threonate — best for brain-focused goals

This form is often marketed for cognition because it’s designed to raise magnesium levels in the brain more effectively. Human research exists, but it’s still a smaller evidence base than for general magnesium health.

• Best for: focus, memory support, cognitive ageing goals
• Notes: dosing is usually measured in grams of the compound, with a smaller amount of elemental magnesium

Magnesium citrate — best for constipation relief (but can be too “active”)

Citrate is popular and often well absorbed, but it can pull water into the intestines — which is exactly why it helps constipation.

• Best for: constipation, occasional bowel regularity support
• Notes: start low; can cause loose stools; often not ideal right before bed

Magnesium malate — best for daytime energy & recovery

Bound to malic acid (involved in cellular energy pathways). Many people find this form “cleaner” in the daytime.

• Best for: fatigue-prone people, muscle soreness, recovery support
• Notes: good morning / lunchtime choice

Magnesium taurate — best for calm + cardiovascular support

Bound to taurine, an amino acid involved in cardiovascular and nervous system regulation.

• Best for: calm focus, stress support, heart-health oriented stacks
• Notes: often a good alternative if glycinate doesn’t suit you

Magnesium oxide — cheap, poorly absorbed, mostly a laxative

Oxide is common because it’s inexpensive, but it’s typically less absorbed than other forms and is more likely to cause GI issues.

• Best for: occasional constipation only (if tolerated)
• Notes: not my first choice for sleep/stress

5) Choose the right magnesium for your goal

If your goal is better sleep

Magnesium glycinate is usually the best starting point.

• Typical use: 100–200 mg elemental magnesium, 1–2 hours before bed
• If you’re sensitive: start at 50–100 mg elemental

If your goal is calmer stress response (and lower “wired” evenings)

Magnesium glycinate or taurate.

• Typical use: 100–200 mg elemental in the evening
• Bonus: pair with breathwork if you’re in a stress spiral

If your goal is constipation relief

Magnesium citrate (or oxide, occasionally) — but be conservative with dosing.

• Typical use: start low, increase gradually based on stool response
• Tip: don’t start this on a day you can’t be near a bathroom

If your goal is energy + muscle recovery

Magnesium malate.

• Typical use: 100–200 mg elemental in the morning or with lunch

If your goal is cognitive support

Magnesium L-threonate can be worth a trial, especially during high-focus periods.

• Typical use: follow the product’s labelled serving; often split doses
• Tip: monitor sleep — some people prefer it earlier in the day

This pairs well with: Deep Sleep Guide and Breathwork That Lowers Cortisol Fast.

6) Timing and stacking

Best timing depends on the type:

• Glycinate / taurate: evening (sleep and calm)
• Malate: morning/lunch (energy and recovery)
• Citrate/oxide: whenever is most practical (but not ideal right before bed for many)
• Threonate: earlier day or split doses (personal preference)

Take with food if you get stomach sensitivity, but many people tolerate glycinate fine either way.

Simple, effective “stack”: Vitamin D is often paired with magnesium because magnesium supports vitamin D metabolism.

See: Vitamin D for Longevity: Dose & Timing.

7) Safety, side effects, and interactions

The most common side effect is diarrhoea — especially with citrate and oxide, or if you take too much too quickly.

Be cautious (and speak to a clinician) if:

• you have kidney disease (magnesium clearance can be impaired)
• you take certain medications (magnesium can interfere with absorption)

Medication spacing tip: magnesium can bind to certain antibiotics and thyroid medication, reducing absorption. A common approach is separating by several hours (confirm with your pharmacist if you’re unsure).

Quality tip: choose products that clearly label elemental magnesium and ideally have third-party testing.

8) My personal approach

I keep it simple and goal-driven:

• Most evenings: glycinate (for deeper sleep and a calmer nervous system)
• On demanding days: a smaller daytime dose (often malate)
• If I’m experimenting with focus: threonate earlier in the day, not right before bed

What made the biggest difference for me wasn’t chasing the “perfect” magnesium — it was getting consistent with one form that I tolerated well.

9) FAQs

How much magnesium should I supplement?
Many people do well with 100–300 mg/day elemental magnesium, depending on diet and goals. If you’re pushing toward higher doses, pay attention to GI tolerance and consider staying within commonly recommended supplemental limits.

Can I take magnesium every day?
Yes — glycinate and taurate are common daily options.

Which type is best for anxiety?
Glycinate is a strong first choice. Taurate is also popular for a calmer stress response.

Why did magnesium give me diarrhoea?
Usually dose (too high) or form (citrate/oxide). Reduce dose, switch to glycinate, and increase gradually.

Related articles

• Vitamin D for Longevity
• CoQ10 & Ubiquinol for Longevity
• Creatine for Cognitive Longevity
• Best Supplements for Longevity (Pillar)

If you take one thing from this…

Choose magnesium based on your goal. Glycinate is usually best for sleep and calm, citrate is mainly for digestion, malate is great for daytime energy, and threonate is the “brain” option.

— Simon, Longevity Simplified

Disclaimer: This article is for educational purposes only and does not constitute medical advice. If you have kidney disease, take prescription medications, or are pregnant/breastfeeding, speak with a qualified clinician before supplementing.

References

• NHS — Vitamins and minerals: Magnesium (UK intake guidance). NHS
• NIH Office of Dietary Supplements — Magnesium Fact Sheet for Health Professionals (upper limits, interactions, evidence summary). NIH ODS
• EFSA — Dietary Reference Values for magnesium (EU reference values). EFSA