Iron
Also known as iron · ferric pyrophosphate · iron(III) diphosphate · liposomal iron
- Supports red blood cell formation and iron status
- Reduces fatigue associated with low iron status
- Taking iron on alternate days improves absorption and tolerability
Research profile
Clinically established16 key studies reviewed
2,965 human trials & reviews
83,166 papers on PubMed
Clinical evidence
What the research shows
Supports red blood cell formation and iron status
EstablishedTwo Cochrane reviews of menstruating women (67 trials daily; 25 trials intermittent) show oral iron lowers anaemia risk and raises haemoglobin and ferritin. This applies to women with low or borderline iron; the benefit is largest when iron is low to begin with. PubMed 27087396PubMed 30699468
Reduces fatigue associated with low iron status
SupportedIn iron-deficient adults who are not anaemic, iron reduced self-reported fatigue modestly (SMD about -0.38) but did not improve objective fitness. In a Swiss BMJ trial the benefit was confined to women with ferritin of 50 µg/L or lower. PubMed 29626044PubMed 12763985PubMed 40945632
Taking iron on alternate days improves absorption and tolerability
SupportedIsotope-labelled studies in iron-depleted women show a single daily dose raises hepcidin and lowers absorption of the next day's dose. Alternate-day dosing absorbed more iron and caused fewer GI side effects at the same total dose. PubMed 26289639PubMed 29032957PubMed 38021373
People with confirmed low iron status (low ferritin, with or without anaemia, for example on a blood test your physician orders), especially menstruating women, frequent blood donors, and people with heavy periods or low red-meat intake. Anaemia itself needs a doctor's diagnosis to rule out blood loss or other causes.
The research is clear: ingredients deliver most when your body actually needs them. That’s why AXEL maps your terrain first, then builds a regimen around you.
Discover your terrainSafety & good-to-know
- Ferrous sulphate roughly doubles the odds of GI side effects compared with placebo (OR 2.32), mainly constipation, nausea and diarrhoea. PubMed 25700159PubMed 27087396
- Daily dosing keeps hepcidin high and increases GI side effects compared with alternate-day dosing. PubMed 38021373PubMed 29032957
- People with haemochromatosis or iron overload should not take iron unless their physician advises it. Keep iron away from children, because accidental overdose is dangerous. (General clinical knowledge; no PMID retrieved.)
Every AXEL regimen can be reviewed by a physician in a consultation.
The studies (16)
Intermittent iron supplementation for reducing anaemia and its associated impairments in adolescent and adult menstruating women.
Cochrane review · Menstruating women · n = 25 trials, 10,996 women · Iron 1–3 times weekly · Various
Intermittent iron worked about as well as daily iron for preventing anaemia (RR 1.09 vs daily) and caused fewer side effects (RR 0.41).
Daily iron supplementation for improving anaemia, iron status and health in menstruating women.
Cochrane review · Menstruating women · n = 67 trials, 8,506 women · Daily oral iron, various doses · ≥5 days/week, various
Daily iron cut the risk of anaemia (RR 0.39, 95% CI 0.25–0.60) and raised haemoglobin by about 5.3 g/L. It also improved exercise performance and reduced symptomatic fatigue. GI side effects roughly doubled (RR 1.99).
Safety and efficacy of liposomal iron for iron deficiency anemia in pediatric population: A systematic review and meta-analysis of randomized controlled trials.
Meta-analysis of RCTs · Children with iron-deficiency anaemia · n = 4 RCTs, 454 · Liposomal vs conventional oral iron · Up to 6 months
Liposomal iron gave a slightly larger haemoglobin rise at 6 months (MD 0.96 g/dL, very high heterogeneity). It caused fewer adverse events (RR 0.29) and less constipation. The authors call the evidence preliminary.
Psychiatric and cognitive outcomes of iron supplementation in non-anemic children, adolescents, and menstruating adults: A meta-analysis and systematic review.
Meta-analysis (12 RCTs + 6 pre-post studies) · Non-anaemic children, adolescents and menstruating adults · n = 18 studies, 1,408 · Oral iron, various · Various
In RCTs, iron improved fatigue (d=0.34) and anxiety. Benefits disappeared when people without iron deficiency were analysed separately.
Effect of postpartum anaemia on maternal health-related quality of life: a systematic review and meta-analysis.
Meta-analysis · Postpartum women with anaemia · n = 27 studies (3 RCTs for fatigue) · Iron supplementation · Various
Three pooled RCTs showed lower fatigue scores with iron (MD -1.85).
Reduced-dose alternate-day oral iron supplementation in women with iron deficiency: a randomized controlled trial.
RCT · Iron-deficient women (ferritin <30) · n = 66 · Sucrosomial ferric pyrophosphate 30 mg daily vs micronised ferric pyrophosphate 21 mg every 48 h · 42 days
Ferritin rose in both groups with no difference between them, and haemoglobin was unchanged. GI effects were mild.
Alternate day versus consecutive day oral iron supplementation in iron-depleted women: a randomized double-blind placebo-controlled study.
RCT · Iron-depleted young Swiss women · n = 150 · 100 mg iron daily vs alternate days · 3–6 months
Ferritin was similar at equal total doses. GI side effects were higher with daily dosing (prevalence ratio 1.56), and iron deficiency was lower at 6 months with alternate days.
Liposomal Mineral Absorption: A Randomized Crossover Trial.
RCT · Healthy adults (crossover) · n = 25 · Liposomal vs standard multivitamin-mineral (about 10 mg iron) · Single dose, 6 h
Serum iron rose more over 6 hours after the liposomal product (iAUC about 50% higher). This was a short-term absorption marker only.
Full research notesOverview, research in progress and study doses
Overview
In people who are actually low in iron, daily oral iron reliably raises haemoglobin and iron stores, and in women with low ferritin it modestly reduces self-reported tiredness. These benefits depend on starting status: there is no evidence that extra iron boosts energy in people with normal iron levels. Liposomal and sucrosomial iron forms looked better tolerated than ferrous sulphate in small, mostly industry-linked trials, but proof that they work better is still preliminary.
Further research
- Liposomal or sucrosomial iron is better absorbed or tolerated than standard iron salts. Small trials, mostly in surgical, kidney, cancer or bowel-disease patients and often manufacturer-linked, found a similar haemoglobin response with fewer gut side effects; a 2026 pooled analysis of 4 paediatric RCTs found fewer adverse events. There are no large head-to-head trials in healthy adults. PubMed 42183880PubMed 33673371PubMed 42927507PubMed 27588568PubMed 36014827
Where the research is still limited
- No evidence it raises energy in people with normal ferritin and haemoglobin.
- It does not improve objective exercise capacity (VO2max) in non-anaemic iron-deficient adults, even though tiredness scores improve.
- The liposomal form has not been shown to work better than standard iron for clinical outcomes in large trials of healthy adults.
Study doses
The Lipo® Iron Drop provides 30 mg elemental iron (as iron fumarate) per 1 ml daily serving, and the Iron Factor capsule provides 30 mg per serving as labelled. Several sucrosomial iron trials used 30 mg/day, while Cochrane trials in women mostly used 60 mg/day or more of ferrous salts. Absorption studies suggest moderate doses taken once a day or on alternate days give the best fractional absorption.