Iron Bisglycinate vs Melatonin

Mineral vs Sleep · evidence-backed comparison

Quick take
  • Iron Bisglycinate has the broader effect profile across the 9 effect categories.
  • Melatonin is cheaper per serving ($0.05 vs $0.18).
  • Melatonin has a slightly cleaner safety profile.
  • Iron Bisglycinate has higher bioavailability (better absorption).

Side-by-side traits

TraitIron BisglycinateMelatonin
Category
MineralSleep
Active compound
Ferrous bisglycinateN-acetyl-5-methoxytryptamine
Form available
Capsule, TabletCapsule, Tablet, Liquid, Gummy
Source
syntheticsynthetic
Typical dose
18–25 mg elemental iron0.3–3 mg
Dose range
18–25 mg0.3–3 mg
Loading protocol
Best taken with
vitamin C, empty stomach (or with food if GI sensitive)30–60 min before bed
Best time of day
morningevening
Bioavailability
How efficiently the body absorbs and utilizes the compound.
Very High (5/5)Moderate (3/5)
Onset time
Cumulative: 4–12 weeksAcute: 30–60 min
Half-life
20–50 min
Evidence level
Quality and quantity of human research.
Strong (multiple RCTs / meta-analyses)Strong (multiple RCTs / meta-analyses)
Overall effect
Subjective effect magnitude.
Moderate (3/5)Moderate (3/5)
Muscle / strength
Low (2/5)Very Low (1/5)
Physical energy
High (4/5)Very Low (1/5)
Focus / cognition
Moderate (3/5)Very Low (1/5)
Mood / stress
Moderate (3/5)Low (2/5)
Sleep quality
Low (2/5)Very High (5/5)
Immunity
Low (2/5)Low (2/5)
Recovery
Post-exercise recovery support.
Moderate (3/5)Moderate (3/5)
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$0.05
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 Melatonin

Pineal-gland hormone that signals 'night-time' to the body. Most useful for jet lag and shifted sleep schedules; lower doses (0.3 mg) often work better than 5–10 mg.

Active compound: N-acetyl-5-methoxytryptamine
Forms: Capsule, Tablet, Liquid, Gummy
Onset: Acute: 30–60 min
sleep-onsetjet-lagcircadian

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

Melatonin safety

Common side effects:

  • Vivid dreams
  • Morning grogginess (high doses)
  • Headache

Avoid if:

  • Autoimmune disease
  • Pregnancy
  • Driving for hours after

Drug interactions:

  • Birth control
  • Anticoagulants
  • Antidepressants
  • Diabetes meds

Common uses

  • Anemia treatment
  • Heavy menstruation
  • Endurance athletes

Stacks well with: Vitamin C

Common uses

  • Jet lag
  • Shift work
  • Sleep onset
  • Circadian rhythm

Stacks well with: Magnesium Glycinate, Glycine

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.