Overview
Essential mineral involved in 300+ enzymatic reactions. Supports energy, muscle function, sleep, and stress response.
Compare Forms
12 formsDifferent chemical forms vary in absorption, side effects, and best use cases. Higher bioavailability scores indicate better absorption.
Magnesium Glycinate
HIGH 100Magnesium bound to the amino acid glycine
💡 High bioavailability, gentle on stomach. Glycine itself has calming properties.
- • Excellent absorption
- • No laxative effect
- • Calming
- • Well-tolerated
- • More expensive
- • Larger capsule size
📝 Best all-around choice for most people
Magnesium Bisglycinate
HIGH 100Chelated magnesium with two glycine molecules (same as glycinate)
💡 High bioavailability, identical to glycinate
- • Excellent absorption
- • No laxative effect
- • Calming
- • More expensive
- • Larger capsule size
📝 Marketing term often used interchangeably with glycinate
Magnesium L-Threonate
HIGH 95Magnesium bound to threonic acid, derived from vitamin C metabolism
💡 Uniquely crosses blood-brain barrier. Raises brain magnesium levels.
- • Crosses BBB
- • Cognitive benefits
- • Memory support
- • Expensive
- • Lower elemental magnesium
- • Multiple doses needed
📝 Best choice for cognitive/brain health focus (Magtein brand)
Magnesium Taurate
HIGH 90Magnesium bound to the amino acid taurine
💡 Good bioavailability. Taurine adds cardiovascular benefits.
- • Heart-healthy
- • Good absorption
- • Taurine benefits
- • Less common
- • Moderate cost
📝 Excellent choice for cardiovascular focus
Magnesium Malate
HIGH 90Magnesium bound to malic acid
💡 Good bioavailability. Malic acid supports ATP production.
- • Energy support
- • Muscle function
- • Good absorption
- • May be energizing (not for night)
📝 Best for daytime energy and muscle support
Magnesium Citrate
HIGH 85Magnesium bound to citric acid
💡 Good bioavailability at normal doses
- • Well-absorbed
- • Affordable
- • Widely available
- • Mild laxative effect at higher doses
📝 Good budget option, may help with constipation
Magnesium Orotate
HIGH 85Magnesium bound to orotic acid
💡 Good bioavailability. Orotic acid may support heart tissue.
- • Heart health benefits
- • Athletic performance
- • Expensive
- • Less common
📝 Popular in Europe for cardiovascular support
Magnesium Chloride
GOOD 75Magnesium salt with chloride
💡 Moderate oral bioavailability. Often used topically.
- • Good for topical use
- • Supports stomach acid
- • Can cause digestive upset orally
📝 Best for topical magnesium oil/spray
Magnesium Sulfate
LOW 50Epsom salt - magnesium with sulfate
💡 Poor oral absorption. Strong laxative effect.
- • Inexpensive
- • Good for baths
- • Muscle relaxation topically
- • Strong laxative effect
- • Poor oral absorption
📝 Best for Epsom salt baths, not oral supplementation
Magnesium Oxide
LOW 40Magnesium bound to oxygen - highest elemental magnesium but poorest absorption
💡 Only ~4% absorbed. Most passes through as laxative.
- • Cheapest
- • High elemental Mg per pill
- • Effective laxative
- • Very poor absorption
- • Strong laxative effect
- • GI upset
📝 Avoid for supplementation - only ~4% absorbed
Magnesium Carbonate
LOW 45Magnesium salt with carbonate
💡 Poor bioavailability, requires stomach acid
- • Antacid properties
- • Inexpensive
- • Poor absorption
- • Can cause gas/bloating
📝 Common in cheap supplements, not recommended
Magnesium Hydroxide
LOW 45Milk of Magnesia
💡 Poor absorption. Primarily a laxative/antacid.
- • Effective laxative
- • Antacid
- • Not for supplementation
📝 Medical use only (Milk of Magnesia)
Dosage
Long-term safe
Most adults deficient
Mechanism of Action
- • Cofactor for ATP production
- • Regulates muscle contraction
- • GABA modulation
- • 300+ enzyme reactions
Evidence Quality
Essential mineral with extensive research
Safety & Contraindications
- • Caution in kidney disease
- • Severe kidney failure
- • Loose stools at high doses
Safe and important
Caution in kidney disease
Interactions
- • Separate from antibiotics
- • Works with B6
- • Pairs with D3
- • Nuts, seeds, greens
Stacking & Synergies
Buying Guide
- • Form specified
- • Glycinate for calming
- • Threonate for brain focus
- • Glycinate for calming/sleep
- • Citrate if constipated
- • Taurate form specifically heart-supportive
- • Very commonly deficient
- • Most people benefit from supplementing
- • Glycinate best for sleep
Frequently Asked About Magnesium
How much Magnesium should I take?
When is the best time to take Magnesium?
Should I take Magnesium with food?
What is the best form of Magnesium?
Does Magnesium interact with medications?
What does Magnesium pair well with?
Who should not take Magnesium?
Top Products with Magnesium
Highest-scored catalog products containing Magnesium, ranked by our scoring engine.
Magnesium+ (Extra Strength) CapsulesNutricost98
Magnesium GlycinateThorne98
Magnesium Bisglycinate CapsulesTransparent Labs98
MediClear-SGS™ - VanillaThorne95
Related Guides
In-depth guides covering Magnesium — protocols, comparisons, and use cases.
Educational content based on published research and our scoring methodology. Not medical advice — consult a qualified healthcare provider before starting, stopping, or changing supplements, especially if you take medications, are pregnant, or have a medical condition.