Caffeine vs Magnesium L-Threonate

Performance vs Sleep · evidence-backed comparison

Quick take
  • Caffeine has the stronger evidence base (strong (multiple rcts / meta-analyses)).
  • Caffeine has the broader effect profile across the 9 effect categories.
  • Caffeine is cheaper per serving ($0.05 vs $1.10).
  • Magnesium L-Threonate has a slightly cleaner safety profile.

Side-by-side traits

TraitCaffeineMagnesium L-Threonate
Category
PerformanceSleep
Active compound
1,3,7-trimethylxanthineMagnesium L-threonate
Form available
Powder, Capsule, TabletCapsule, Powder
Source
syntheticsynthetic
Typical dose
100–300 mg1.5–2 g (≈144 mg elemental Mg)
Dose range
100–300 mg1500–2000 mg
Loading protocol
Best taken with
waterevening
Best time of day
morningevening
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Very High (5/5)
Onset time
Acute: 30–60 minCumulative: 4–12 weeks
Half-life
5–6 hours (plasma)
Evidence level
Quality and quantity of human research.
Strong (multiple RCTs / meta-analyses)Limited (small studies)
Overall effect
Subjective effect magnitude.
High (4/5)Moderate (3/5)
Muscle / strength
Low (2/5)Very Low (1/5)
Physical energy
Very High (5/5)Very Low (1/5)
Focus / cognition
Very High (5/5)High (4/5)
Mood / stress
High (4/5)Moderate (3/5)
Sleep quality
Very Low (1/5)High (4/5)
Immunity
Low (2/5)Very Low (1/5)
Recovery
Post-exercise recovery support.
Very Low (1/5)Very Low (1/5)
Longevity / healthspan
Moderate (3/5)Moderate (3/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
High (4/5)Very High (5/5)
Price per serving
Approximate USD per typical daily dose.
$0.05$1.10
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Caffeine

The most effective legal performance booster. Boosts strength, endurance, focus, and pain tolerance — but tolerance builds within weeks.

Active compound: 1,3,7-trimethylxanthine
Forms: Powder, Capsule, Tablet
Onset: Acute: 30–60 min
energyfocusperformancefat-loss

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

Caffeine safety

Common side effects:

  • Jitters
  • Insomnia
  • Increased heart rate
  • GI upset

Avoid if:

  • Anxiety disorders
  • Heart arrhythmias
  • Pregnancy (limit 200 mg/day)

Drug interactions:

  • MAOIs
  • Theophylline
  • Birth control

Magnesium L-Threonate safety

Common side effects:

  • Drowsiness
  • Headache (rare)

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

Common uses

  • Energy
  • Pre-workout
  • Focus
  • Fat loss

Stacks well with: L-Theanine, Creatine Monohydrate, Beta-Alanine

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.