Magnesium Glycinate vs Vitamin K2 (MK-7)

Sleep vs Vitamin · evidence-backed comparison

Quick take
  • Magnesium Glycinate has the broader effect profile across the 9 effect categories.
  • Vitamin K2 (MK-7) is cheaper per serving ($0.18 vs $0.25).
  • Magnesium Glycinate has a slightly cleaner safety profile.
  • Magnesium Glycinate has higher bioavailability (better absorption).

Side-by-side traits

TraitMagnesium GlycinateVitamin K2 (MK-7)
Category
SleepVitamin
Active compound
Magnesium chelated to glycineMenaquinone-7
Form available
Capsule, Powder, TabletSoftgel, Capsule
Source
syntheticmicrobial
Typical dose
200–400 mg elemental Mg100–200 mcg daily
Dose range
200–400 mg100–200 mcg
Loading protocol
Best taken with
evening, with waterfat-containing meal
Best time of day
eveningany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)High (4/5)
Onset time
Acute: 1–3 hoursCumulative: 4–12 weeks
Half-life
~28 hours (Mg)~72 hours
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Low (2/5)
Muscle / strength
Moderate (3/5)Very Low (1/5)
Physical energy
Low (2/5)Very Low (1/5)
Focus / cognition
Low (2/5)Very Low (1/5)
Mood / stress
Moderate (3/5)Very Low (1/5)
Sleep quality
High (4/5)Very Low (1/5)
Immunity
Low (2/5)Low (2/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Low (2/5)
Longevity / healthspan
High (4/5)High (4/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
Very High (5/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.25$0.18
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 Vitamin K2 (MK-7)

Activates osteocalcin and matrix-Gla protein to direct calcium into bones rather than arteries. Most evidence comes from the 3-year Rotterdam study.

Active compound: Menaquinone-7
Forms: Softgel, Capsule
Onset: Cumulative: 4–12 weeks
bonearterial-healthcalcium-regulationlongevity

Magnesium Glycinate safety

Common side effects:

  • Mild laxative effect (rare)
  • Drowsiness

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates
  • Antibiotics (timing)

Vitamin K2 (MK-7) safety

Common side effects:

  • Generally none

Avoid if:

  • Warfarin therapy

Drug interactions:

  • Warfarin (major)
  • Other anticoagulants

Common uses

  • Sleep quality
  • Anxiety
  • Muscle cramps
  • RLS

Stacks well with: Zinc, Vitamin D3, Melatonin

Common uses

  • Bone density
  • Arterial health
  • Calcium routing

Stacks well with: Vitamin D3, Magnesium Glycinate

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.