Glucosamine Sulfate vs Vitamin K2 (MK-7)

Joint & Recovery vs Vitamin · evidence-backed comparison

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

Side-by-side traits

TraitGlucosamine SulfateVitamin K2 (MK-7)
Category
Joint & RecoveryVitamin
Active compound
Glucosamine sulfate (or HCl)Menaquinone-7
Form available
Capsule, TabletSoftgel, Capsule
Source
marinemicrobial
Typical dose
1500 mg daily100–200 mcg daily
Dose range
1500 mg100–200 mcg
Loading protocol
Best taken with
with foodfat-containing meal
Best time of day
anyany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Moderate (3/5)High (4/5)
Onset time
Cumulative: 8–24 weeksCumulative: 4–12 weeks
Half-life
~72 hours
Evidence level
Quality and quantity of human research.
Moderate (some RCTs)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Low (2/5)Low (2/5)
Muscle / strength
Very Low (1/5)Very Low (1/5)
Physical energy
Very Low (1/5)Very Low (1/5)
Focus / cognition
Very Low (1/5)Very Low (1/5)
Mood / stress
Very Low (1/5)Very Low (1/5)
Sleep quality
Very Low (1/5)Very Low (1/5)
Immunity
Very Low (1/5)Low (2/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Low (2/5)
Longevity / healthspan
Moderate (3/5)High (4/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.25$0.18
Vegan friendly
NoYes
Gluten free
YesYes
3rd-party tested
YesYes

About Glucosamine Sulfate

Cartilage building block. Most evidence supports the sulfate form for knee osteoarthritis with months of consistent use.

Active compound: Glucosamine sulfate (or HCl)
Forms: Capsule, Tablet
Onset: Cumulative: 8–24 weeks
jointsosteoarthritiscartilage

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

Glucosamine Sulfate safety

Common side effects:

  • Mild GI upset
  • Headache

Avoid if:

  • Shellfish allergy
  • Diabetes (mild glucose effect)

Drug interactions:

  • Warfarin (mild)
  • Acetaminophen

Vitamin K2 (MK-7) safety

Common side effects:

  • Generally none

Avoid if:

  • Warfarin therapy

Drug interactions:

  • Warfarin (major)
  • Other anticoagulants

Common uses

  • Knee osteoarthritis
  • Joint pain
  • Cartilage support

Stacks well with: MSM (Methylsulfonylmethane), Curcumin (with Piperine)

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.