Magnesium L-Threonate vs Quercetin

Sleep vs Immune · evidence-backed comparison

Quick take
  • Quercetin has the stronger evidence base (moderate (some rcts)).
  • Magnesium L-Threonate has the broader effect profile across the 9 effect categories.
  • Quercetin is cheaper per serving ($0.35 vs $1.10).
  • Magnesium L-Threonate has a slightly cleaner safety profile.
  • Magnesium L-Threonate has higher bioavailability (better absorption).

Side-by-side traits

TraitMagnesium L-ThreonateQuercetin
Category
SleepImmune
Active compound
Magnesium L-threonateQuercetin
Form available
Capsule, PowderCapsule, Tablet
Source
syntheticplant
Typical dose
1.5–2 g (≈144 mg elemental Mg)500–1000 mg daily
Dose range
1500–2000 mg500–1000 mg
Loading protocol
Best taken with
eveningvitamin C (potentiates)
Best time of day
eveningany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Low (2/5)
Onset time
Cumulative: 4–12 weeksCumulative: 2–6 weeks
Half-life
~17 hours
Evidence level
Quality and quantity of human research.
Limited (small studies)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Low (2/5)
Muscle / strength
Very Low (1/5)Very Low (1/5)
Physical energy
Very Low (1/5)Low (2/5)
Focus / cognition
High (4/5)Very Low (1/5)
Mood / stress
Moderate (3/5)Very Low (1/5)
Sleep quality
High (4/5)Very Low (1/5)
Immunity
Very Low (1/5)High (4/5)
Recovery
Post-exercise recovery support.
Very Low (1/5)Moderate (3/5)
Longevity / healthspan
Moderate (3/5)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.
$1.10$0.35
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

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

About Quercetin

Polyphenol with antihistamine and senolytic properties. Common in protocols for allergies and viral infections; pair with vitamin C.

Active compound: Quercetin
Forms: Capsule, Tablet
Onset: Cumulative: 2–6 weeks
antihistaminesenolyticimmunepolyphenol

Magnesium L-Threonate safety

Common side effects:

  • Drowsiness
  • Headache (rare)

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

Quercetin safety

Common side effects:

  • Headache
  • Tingling extremities (high doses)

Avoid if:

  • Kidney disease

Drug interactions:

  • Cyclosporine
  • Quinolone antibiotics
  • Anticoagulants

Common uses

  • Cognitive aging
  • Deep sleep
  • Memory

Stacks well with: Zinc, Vitamin D3

Common uses

  • Seasonal allergies
  • Immune support
  • Senescent cell clearance

Stacks well with: Vitamin C, Zinc

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.