Iron and Ferritin Screening
Screen ferritin before supplementing iron. Low ferritin can contribute to fatigue, particularly in menstruating women, but iron should be guided by labs and clinician review.
Dosage & Timing
Evidence Strength
4/5 — StrongRCTs and systematic reviews support fatigue improvement from iron supplementation in non-anemic people with low iron stores, but benefit depends on baseline status. The safe MVP recommendation is lab-guided screening and clinician-directed correction.
Overview
Check ferritin and iron status before considering iron supplementation, especially for menstruating women, endurance athletes, vegetarians, vegans, and people with unexplained fatigue. Iron can help when deficiency is present, but unnecessary supplementation can be harmful, so this protocol emphasizes testing, clinician review, and follow-up labs rather than self-prescribing.
How To Do It
Identify risk
Consider screening if you menstruate, train endurance volume, avoid meat, donate blood, or have persistent unexplained fatigue.
Order labs
Discuss ferritin, CBC, serum iron, transferrin saturation, and inflammation context with a clinician.
Supplement only if indicated
Use dose and form recommended by a qualified clinician. Do not start iron solely because fatigue is present.
Separate from blockers
If supplementing, avoid taking iron with calcium, coffee, tea, or interacting medications unless your clinician advises otherwise.
Retest
Repeat labs after 8-12 weeks to confirm response and avoid overshooting.
Progression Path
Start with ferritin, CBC, and iron studies. If low, correct with clinician guidance and repeat labs after 8-12 weeks before continuing long term.
The Evidence
Each claim is linked to its source study. Confidence reflects the study design — systematic reviews and RCTs rank highest.
Effect of iron supplementation on fatigue in nonanemic menstruating women with low ferritin: a randomized controlled trial↗
Iron supplementation reduced fatigue in nonanemic menstruating women with ferritin below 50 micrograms/L.
Efficacy of iron supplementation on fatigue and physical capacity in non-anaemic iron-deficient adults: a systematic review↗
Iron supplementation reduced subjective fatigue in iron-deficient non-anemic adults, with less consistent effects on objective physical capacity.
Primary Literature
Who Popularized This
Interactions & Warnings
Contraindications
- ⚠Hemochromatosis
- ⚠High ferritin or iron overload
- ⚠Active infection or inflammation affecting ferritin interpretation
- ⚠Pregnancy without clinician guidance
Interactions
- •Iron absorption is reduced by calcium, coffee, tea, and some medications
- •Iron can interact with levothyroxine and certain antibiotics
Measurable Outcomes
Equipment Needed
- • Ferritin and iron panel lab access
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