Magnesium Glycinate vs Magnesium L-Threonate

Sleep vs Sleep · evidence-backed comparison

Quick take
  • Magnesium Glycinate has the stronger evidence base (moderate (some rcts)).
  • Magnesium Glycinate has the broader effect profile across the 9 effect categories.
  • Magnesium Glycinate is cheaper per serving ($0.25 vs $1.10).

Side-by-side traits

TraitMagnesium GlycinateMagnesium L-Threonate
Category
SleepSleep
Active compound
Magnesium chelated to glycineMagnesium L-threonate
Form available
Capsule, Powder, TabletCapsule, Powder
Source
syntheticsynthetic
Typical dose
200–400 mg elemental Mg1.5–2 g (≈144 mg elemental Mg)
Dose range
200–400 mg1500–2000 mg
Loading protocol
Best taken with
evening, with waterevening
Best time of day
eveningevening
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Very High (5/5)
Onset time
Acute: 1–3 hoursCumulative: 4–12 weeks
Half-life
~28 hours (Mg)
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Limited (small studies)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Moderate (3/5)
Muscle / strength
Moderate (3/5)Very Low (1/5)
Physical energy
Low (2/5)Very Low (1/5)
Focus / cognition
Low (2/5)High (4/5)
Mood / stress
Moderate (3/5)Moderate (3/5)
Sleep quality
High (4/5)High (4/5)
Immunity
Low (2/5)Very Low (1/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Very Low (1/5)
Longevity / healthspan
High (4/5)Moderate (3/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
Very High (5/5)Very High (5/5)
Price per serving
Approximate USD per typical daily dose.
$0.25$1.10
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Magnesium Glycinate

The best-tolerated, best-absorbed magnesium form for sleep and stress. Doesn't cause loose stools like citrate.

Active compound: Magnesium chelated to glycine
Forms: Capsule, Powder, Tablet
Onset: Acute: 1–3 hours
sleepstressmuscle-relaxationnon-laxative

About Magnesium L-Threonate

Only magnesium form proven to cross the blood-brain barrier in animals. Marketed for cognitive aging and sleep, but premium-priced.

Active compound: Magnesium L-threonate
Forms: Capsule, Powder
Onset: Cumulative: 4–12 weeks
brainsleepmemoryblood-brain-barrier

Magnesium Glycinate safety

Common side effects:

  • Mild laxative effect (rare)
  • Drowsiness

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates
  • Antibiotics (timing)

Magnesium L-Threonate safety

Common side effects:

  • Drowsiness
  • Headache (rare)

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

Common uses

  • Sleep quality
  • Anxiety
  • Muscle cramps
  • RLS

Stacks well with: Zinc, Vitamin D3, Melatonin

Common uses

  • Cognitive aging
  • Deep sleep
  • Memory

Stacks well with: Zinc, Vitamin D3

Medical disclaimer

SupplementDuel is for educational purposes only and is not medical advice. Consult a physician before starting, stopping, or combining supplements — especially if you are pregnant, breastfeeding, take prescription medication, or have a chronic condition.