Iron Bisglycinate vs Magnesium Citrate

Mineral vs Sleep · evidence-backed comparison

Quick take
  • Iron Bisglycinate has the stronger evidence base (strong (multiple rcts / meta-analyses)).
  • Iron Bisglycinate has the broader effect profile across the 9 effect categories.
  • Magnesium Citrate is cheaper per serving ($0.12 vs $0.18).
  • Magnesium Citrate has a slightly cleaner safety profile.
  • Iron Bisglycinate has higher bioavailability (better absorption).

Side-by-side traits

TraitIron BisglycinateMagnesium Citrate
Category
MineralSleep
Active compound
Ferrous bisglycinateMagnesium citrate
Form available
Capsule, TabletCapsule, Powder, Tablet, Liquid
Source
syntheticsynthetic
Typical dose
18–25 mg elemental iron200–400 mg elemental Mg
Dose range
18–25 mg200–400 mg
Loading protocol
Best taken with
vitamin C, empty stomach (or with food if GI sensitive)any time, with water
Best time of day
morningany
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)High (4/5)
Onset time
Cumulative: 4–12 weeksAcute: 1–3 hours
Half-life
Evidence level
Quality and quantity of human research.
Strong (multiple RCTs / meta-analyses)Moderate (some RCTs)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Moderate (3/5)
Muscle / strength
Low (2/5)Low (2/5)
Physical energy
High (4/5)Low (2/5)
Focus / cognition
Moderate (3/5)Very Low (1/5)
Mood / stress
Moderate (3/5)Low (2/5)
Sleep quality
Low (2/5)Moderate (3/5)
Immunity
Low (2/5)Very Low (1/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Low (2/5)
Longevity / healthspan
Very Low (1/5)Moderate (3/5)
Safety rating
5 = exceptionally well-tolerated; 1 = significant risk profile.
Moderate (3/5)High (4/5)
Price per serving
Approximate USD per typical daily dose.
$0.18$0.12
Vegan friendly
YesYes
Gluten free
YesYes
3rd-party tested
YesYes

About Iron Bisglycinate

Best-tolerated iron form for treating deficiency anemia. Don't supplement without a confirmed low ferritin / low Hgb test.

Active compound: Ferrous bisglycinate
Forms: Capsule, Tablet
Onset: Cumulative: 4–12 weeks
anemiaenergymenstruationendurance

About Magnesium Citrate

Most affordable absorbable magnesium. Doubles as a mild laxative — useful if constipated, less ideal if not.

Active compound: Magnesium citrate
Forms: Capsule, Powder, Tablet, Liquid
Onset: Acute: 1–3 hours
sleepconstipationvaluemuscle

Iron Bisglycinate safety

Common side effects:

  • Constipation (less than ferrous sulfate)
  • Dark stools

Avoid if:

  • Hemochromatosis
  • Iron overload
  • Untested males without deficiency

Drug interactions:

  • Levothyroxine
  • Calcium
  • PPIs

Magnesium Citrate safety

Common side effects:

  • Loose stools (often desired)
  • GI cramps

Avoid if:

  • Severe kidney disease

Drug interactions:

  • Bisphosphonates

Common uses

  • Anemia treatment
  • Heavy menstruation
  • Endurance athletes

Stacks well with: Vitamin C

Common uses

  • General magnesium repletion
  • Constipation
  • Sleep

Stacks well with: 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.