Lactoferrin for Iron-Deficiency Anemia: Survived vs Retracted Evidence

By Erin Rose · Updated July 19, 2026 · Methodology

Educational overview — not medical advice. This is not a substitute for a diagnosed anemia treatment plan; work with a doctor and follow-up bloodwork. This statement has not been evaluated by the FDA. This product is not intended to diagnose, treat, cure, or prevent any disease.

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Start with the trial that actually holds up: Nappi 2009

Nappi et al. 2009, published in Acta Obstetricia et Gynecologica Scandinavica, is a prospective randomized controlled trial of 97 pregnant women with iron-deficiency anemia — 49 given bovine lactoferrin, 48 given ferrous sulfate, over 30 days. The primary endpoint was change in hemoglobin, and it was met in both arms: hemoglobin, ferritin, and serum iron all significantly increased in both groups, with no significant between-group difference. The genuinely useful finding is secondary but practically important: "median scores of abdominal pain and constipation were significantly higher" in the ferrous sulfate group — lactoferrin was better tolerated. This trial has real limits worth naming: it wasn't reported as fully double-blinded across every measure, it was single-center, and no funding/COI statement was located in the abstract. But it has one thing the two much larger, more-cited trials in this niche don't: it has not been retracted.

The retraction story, in full

Two trials did far more to build lactoferrin's "beats iron for pregnancy anemia" reputation than Nappi 2009 ever did — and both were withdrawn. Rezk et al. 2016, "Lactoferrin versus ferrous sulphate for the treatment of iron deficiency anemia during pregnancy: a randomized clinical trial," and Darwish et al. 2019, "Lactoferrin plus health education versus total dose infusion (TDI) of low-molecular weight (LMW) iron dextran for treating iron deficiency anemia (IDA) in pregnancy: a randomized controlled trial," both appeared in the Journal of Maternal-Fetal & Neonatal Medicine and both were formally retracted in December 2023 — retraction notices at PMID 37466255 ("RETRACTED ARTICLE: Lactoferrin versus ferrous sulphate for the treatment of iron deficiency anemia during pregnancy: a randomized clinical trial") and PMID 36658737 ("Statement of Retraction: lactoferrin plus health education versus total dose infusion (TDI) of low-molecular weight (LMW) iron dextran for treating iron deficiency anemia (IDA) in pregnancy: a randomized controlled trial"). The Darwish trial had already drawn a pre-retraction statistical-concerns letter in 2019 (PMID 29690808) with a published author reply (PMID 29877119). Neither retraction notice's fetched text states the specific reason for withdrawal — this site treats both as data-integrity retractions, not benign administrative ones, and neither trial's findings are used as evidence here, anywhere.

This matters beyond just the two trials themselves. Abu Hashim, Foda & Ghayaty 2017, a meta-analysis of 4 RCTs and 600 pregnant women published in the European Journal of Obstetrics, Gynecology, and Reproductive Biology, reported hemoglobin change at 4 weeks favoring lactoferrin (MD 0.77 g/dL, 95% CI 0.04-1.55, p=0.04, significant only in the moderate-anemia subgroup), plus fewer GI side effects and no difference in preterm birth, birthweight, or neonatal death. It was published one year after the now-retracted Rezk 2016 trial, in the exact same narrow niche — and while its abstract doesn't itemize its included studies by author, so this can't be confirmed with certainty from the fetched text, the overlap is too specific to ignore. Treat its pooled effect size with real caution; it should not be presented as clean, unimpeachable evidence. The most recent synthesis, Christofi et al. 2024 in BMC Nutrition (19 trials, 7 pooled against ferrous sulfate specifically), reported mean hemoglobin concentration favoring lactoferrin (SMD -0.81, 95% CI -1.21 to -0.42, p<0.0001) — but with I²=95.8%, an extremely high heterogeneity figure that is itself a red flag, and the fetched abstract does not visibly address the Rezk/Darwish retractions even though this 2024 publication covers trials through 2022. Do not cite the SMD -0.81 figure as a clean, settled number; it is a positive but statistically noisy signal from a literature that includes retracted trials.

The mechanistic backing — and why it isn't the same product

The plausibility argument for lactoferrin working differently than iron salts comes from Lönnerdal & Bryant 2006, a randomized crossover trial of 20 healthy young US women using radiolabeled (&sup5;&sup9;Fe) iron-absorption methodology. Its primary endpoint — iron absorption from lactoferrin vs. ferrous sulfate — was met, with no significant difference (20.4±15.3% for lactoferrin vs. 18.8±13.2% for ferrous sulfate). This is real, useful mechanistic support: lactoferrin binds iron directly and can plausibly deliver it via a different absorption pathway than a ferrous salt. But it tested recombinant human lactoferrin — a rice-expressed research compound — not the bovine lactoferrin sold retail and used in the clinical anemia trials above. It's also a small trial (n=20) measuring an absorption endpoint, not a clinical anemia-correction outcome. Use this to understand why lactoferrin might plausibly work, not as proof that the capsule on the shelf performs identically to what was tested here.

What this means if you're treating a diagnosed anemia

Standard iron salts remain the first-line, most-studied treatment for iron-deficiency anemia, and the iron category is the place to start for most people, especially given how much larger and more consistent that evidence base is. If GI intolerance to ferrous sulfate is specifically your problem, a gentler iron form like bisglycinate (see ferrous sulfate vs bisglycinate) is the better-evidenced next step before lactoferrin. Lactoferrin is worth discussing with a doctor as a second-line option in that specific scenario — not as a first choice, and not as a substitute for follow-up bloodwork. Iron-deficiency anemia in a man or a postmenopausal woman, in particular, warrants finding the underlying cause before treating the number.

Frequently asked questions

Related

• Lactoferrin: what it is & who it's for
• Lactoferrin dosage guide
• Best lactoferrin
• Best iron supplement — the direct, first-line comparison category
• Ferrous sulfate vs bisglycinate — a better-evidenced GI-tolerability alternative

Sources