Iron
Useful mainly for people with confirmed iron deficiency or iron-deficiency anemia — especially menstruating women, pregnant women, and vegans/vegetarians.
Quick decision guide
May help most
People with confirmed iron deficiency or iron-deficiency anemia — especially menstruating women, pregnant women, and vegans/vegetarians
Common dosing range
65 mg elemental iron (325 mg ferrous sulfate) once to three times daily for deficiency; 18–27 mg/day for maintenance/pregnancy
When to expect effects
Weeks (symptoms); months (to replenish stores)
Watch out for
Do not supplement without confirmed deficiency — excess iron is harmful and supplementation is not indicated in healthy men or post-menopausal women
What is it
Iron is an essential mineral required for hemoglobin (oxygen transport in red blood cells), myoglobin (oxygen storage in muscle), and many enzymes. It is the world's most common nutritional deficiency.
Is it worth it for you?
Use this as a quick fit check, not a diagnosis.
Worth considering if…
Probably skip if…
Evidence at a glance
| Goal | Effect | Best fit | Time |
|---|---|---|---|
iron deficiency anemia Strong Evidence | Restores hemoglobin and resolves anemia symptoms in confirmed deficiency | Menstruating women, pregnant women, vegans, athletes, infants with dietary deficiency | Weeks for symptom relief; 3–6 months to restore stores |
restless legs syndrome Good Evidence | Meaningful symptom reduction in patients with low ferritin (<50 ng/mL) | Adults with restless legs syndrome and serum ferritin below 50–75 ng/mL | Weeks to months |
exercise performance in iron deficiency Good Evidence | Significant improvement in VO2max and endurance in iron-deficient athletes | Endurance athletes with iron deficiency (with or without anemia) | Weeks |
iron deficiency anemia
- Effect
- Restores hemoglobin and resolves anemia symptoms in confirmed deficiency
- Best fit
- Menstruating women, pregnant women, vegans, athletes, infants with dietary deficiency
- Time
- Weeks for symptom relief; 3–6 months to restore stores
restless legs syndrome
- Effect
- Meaningful symptom reduction in patients with low ferritin (<50 ng/mL)
- Best fit
- Adults with restless legs syndrome and serum ferritin below 50–75 ng/mL
- Time
- Weeks to months
exercise performance in iron deficiency
- Effect
- Significant improvement in VO2max and endurance in iron-deficient athletes
- Best fit
- Endurance athletes with iron deficiency (with or without anemia)
- Time
- Weeks
Evidence for 3 uses
AI-assisted evidence assessment — talk to your doctor before relying on any single supplement.
iron deficiency anemia
Corrects deficiencyIron is the world's most common nutritional deficiency. Supplementation consistently corrects iron-deficiency anemia, restoring hemoglobin to normal within 4–8 weeks and resolving associated symptoms (fatigue, dyspnea, pallor). Ferritin stores take longer to replenish and require continued treatment after hemoglobin normalization.
Bottom line: Oral iron supplementation is highly effective for iron-deficiency anemia when the cause is dietary — the core use case with the strongest evidence.
restless legs syndrome
Disease adjunctMultiple RCTs and guidelines support iron supplementation (oral or IV) for restless legs syndrome associated with low or low-normal ferritin. Both the American Academy of Sleep Medicine and European RLS Study Group recommend iron repletion as first-line for patients with ferritin below a threshold. Effect depends on achieving adequate ferritin levels.
Bottom line: Iron supplementation is a first-line intervention for RLS when ferritin is low — test ferritin before starting.
exercise performance in iron deficiency
Corrects deficiencyRCTs in iron-deficient athletes show supplementation improves maximal oxygen consumption and endurance performance. The effect is present even in non-anemic iron deficiency, where tissue iron depletion still impairs muscle oxidative metabolism. No benefit is seen in iron-replete athletes.
Bottom line: Iron supplementation restores exercise performance in deficient athletes but provides no performance advantage when iron status is normal.
How it works
How to take it
What to track
5 commercial forms
Compare the main delivery options and what they’re best suited for.
Ferrous sulfate
Most common prescription/OTC iron.
Standard, well-absorbed, cheap; GI side effects common.
Ferrous gluconate / fumarate
Common alternatives.
Slightly better tolerated than sulfate.
Iron bisglycinate (chelated)
Preferred when GI side effects are a problem.
Better tolerated; similar absorption.
Polysaccharide iron complex
Brand names include Niferex.
Well-tolerated; some debate about effectiveness vs ferrous salts.
Heme iron polypeptide
Less GI effect; more expensive.
Animal-derived heme iron; well-absorbed.
Safety
Know the common side effects, key cautions, and who should avoid it.
Common side effects
Serious risks
Acute iron poisoning — can be fatal in children; keep supplements locked away
Iron overload with long-term excess supplementation in adults — oxidative tissue damage
Who should avoid it
- People with hereditary hemochromatosis or other iron-overload conditions
- Healthy adult men and post-menopausal women without confirmed deficiency
- People with transfusion-dependent anemias
Pregnancy & breastfeeding
Iron needs increase substantially in pregnancy (27 mg/day RDA); prenatal vitamins typically include iron, but supplemental doses should be guided by ferritin testing.
Interactions
Iron binds levothyroxine in the gut — separate by at least 4 hours
Iron chelates fluoroquinolones, reducing antibiotic absorption — separate by 2–4 hours
Mutual absorption impairment — separate by 2–4 hours
Calcium competes with iron for absorption — do not take simultaneously
Reduce gastric acid needed for iron reduction and absorption
Enhances non-heme iron absorption — beneficial interaction
Documented interactions
Evidence-graded pair pages with sources, dosing notes, and timing guidance — a complement to the narrative section above.
Warnings (17)
+ doxycycline
highIron forms an insoluble chelate complex with doxycycline in the gut, sharply reducing absorption of the antibiotic. In controlled human studies, ferrous sulfate taken together with doxycycline cut serum antibiotic levels substantially, which can undermine treatment.
+ zinc
moderateHigh-dose iron and zinc supplements can compete for absorption in the small intestine when taken together, especially in solution on an empty stomach, potentially reducing the effectiveness of one or both minerals. The competition is minimal when the minerals are taken with food or hours apart, or at ordinary dietary amounts.
+ ferritin test
moderateRecent oral or intravenous iron transiently raises serum iron and transferrin saturation (and, after IV iron, ferritin itself), so iron studies drawn too soon can be misread.
+ levothyroxine
moderateWhen taken at the same time, iron can reduce how much levothyroxine your body absorbs by forming a poorly soluble complex in the gut, which can blunt the effect of your thyroid medication and raise TSH.
Beneficial pairs (2)
+ vitamin a
synergyVitamin A and beta-carotene appear to improve absorption of non-heme iron from plant foods by forming soluble complexes with iron that keep it from binding to phytates and polyphenols in the gut. In controlled human absorption studies, adding vitamin A to a grain-based meal increased the amount of iron absorbed.
+ copper
synergyCopper and iron work together in red blood cell production: copper-dependent ceruloplasmin is required to mobilize iron for hemoglobin, so inadequate copper can cause an anemia that mimics iron deficiency and does not respond to iron alone.
Protocols featuring Iron
Evidence-backed routines where Iron plays a role.
Women's Essentials 30-50
general
The decade between 30 and 50 is when women navigate the most physiologically diverse stretch of adult life: menstruation, possibly pregnancy and postpartum, and the start of perimenopause. The everyday nutritional needs cover iron (menstruation), folate (preconception or peri-pregnancy), vitamin D, magnesium, omega-3, and a B-complex. Bone density also begins its first measurable decline, making early attention to vitamin D and weight-bearing exercise especially leveraged. This protocol is calibrated for women in this window — layer goal-specific protocols (PMS Support, Perimenopause Support, Fertility Prep, Postpartum Support, Hair Loss, Bone Density) on top as life stage requires.
PPI / Acid Blocker Companion
medication
Proton pump inhibitors (omeprazole/Prilosec, esomeprazole/Nexium, pantoprazole/Protonix, lansoprazole/Prevacid) are among the most-prescribed medications globally — and frequently used much longer than recommended. Long-term PPI use (more than 6-12 months) is associated with multiple documented nutrient malabsorption issues because stomach acid is REQUIRED for absorbing B12, calcium, iron, magnesium, and zinc. Reduced stomach acid also alters the gut microbiome, increases risk of C. difficile and pneumonia infections, and is associated (though not necessarily causal) with osteoporotic fractures, dementia, and kidney issues in long-term users. This protocol is for adults ACTIVELY on long-term PPIs or H2 blockers (famotidine/Pepcid, ranitidine — now removed for NDMA contamination). The supplements address the documented nutrient gaps that develop with chronic acid suppression. CRITICAL secondary message: many PPI users could safely wean off if working with their doctor. PPIs are appropriate for confirmed Barrett''s esophagus, erosive esophagitis, peptic ulcer disease — but are commonly prescribed long-term for milder reflux that would respond to lifestyle changes and intermittent H2 blocker use. Talk to your prescriber about whether you''re actually a long-term PPI candidate or could try weaning. See Acid Reflux / Heartburn protocol for non-pharmaceutical alternatives.
Kids ADHD & Focus
kids
ADHD affects roughly 10% of US children and is a real, well-studied neurodevelopmental condition — not a parenting failure and not a label to avoid. The gold-standard treatments are behavioral interventions (parent training, school accommodations, CBT for older kids) combined with stimulant medication (methylphenidate, amphetamines). Both have strong evidence, and combined approaches outperform either alone. Supplements do NOT replace properly-indicated stimulant medication for moderate-to-severe ADHD — kids who genuinely need pharmacological treatment shouldn''t be denied it based on parental preference. That said, supplements have a legitimate adjunctive role: addressing micronutrient deficiencies that worsen attention (iron, zinc, magnesium, omega-3), supporting kids with mild presentations who don''t yet meet medication thresholds, helping medicated kids whose stimulants cause side effects, or providing parents wanting a structured non-pharmacological trial before escalating. The evidence is modest but real, especially for omega-3 (EPA-dominant) and for correcting confirmed deficiencies in iron and zinc. Get a proper evaluation by a pediatric psychiatrist or developmental pediatrician first — diagnosis matters because it unlocks treatments (including supplements) that match the actual problem.
Trimester 1 Prenatal
maternal
The first trimester is the highest-stakes window of pregnancy nutritionally. Neural tube formation completes by week 4-6 (often before pregnancy is even known), organogenesis is in full swing, and the most common early-pregnancy symptom — morning sickness — affects 70-85% of pregnancies. This protocol covers the four nutritional priorities for trimester 1: a methylfolate-containing prenatal (the single most-evidenced intervention in obstetric nutrition for preventing neural tube defects), vitamin B6 + ginger for nausea (both ACOG-supported as first-line), choline for fetal brain and liver development (commonly under-consumed), and iron when ferritin is confirmed low. This protocol replaces your Fertility Prep — Women stack once pregnancy is confirmed. Many supplements that were fine pre-conception (ashwagandha, vitex, berberine, high-dose vitamin A, certain herbal blends) are contraindicated in pregnancy. Coordinate every supplement with your OB.
Hair Loss Support — Women
beauty
Female hair loss has dozens of possible causes — most of them addressable. The most common drivers are iron deficiency (especially in menstruating, postpartum, or vegetarian women), thyroid dysfunction, postpartum telogen effluvium, perimenopausal androgen sensitivity, and chronic stress. The supplement stack here addresses the nutritional gaps and androgen-sensitivity pathways that respond to oral supplementation. The single most important step is correctly identifying YOUR cause — a CBC, ferritin, TSH, free T3/T4, and a vitamin D level cost very little and answer most questions. Topical minoxidil (Rogaine, generic) has the strongest evidence of any hair-loss intervention and is FDA-approved for women — it is not in this stack but it is the gold-standard pharmacological lever and pairs with the nutritional foundation here.
IBD Support (Crohn's & Ulcerative Colitis)
autoimmune
Inflammatory bowel disease (IBD) affects roughly 3 million Americans across two main forms: Crohn''s disease (can involve any segment of the GI tract, transmural inflammation, often complicated by strictures, fistulas, and surgical resections) and ulcerative colitis (continuous mucosal inflammation limited to the colon, with bloody diarrhea and urgency as hallmark symptoms). This is fundamentally different from IBS (irritable bowel syndrome), which is a functional disorder without structural damage. IBD involves chronic, often progressive intestinal inflammation, ulceration, and sometimes systemic complications (uveitis, arthritis, primary sclerosing cholangitis, increased colorectal cancer risk). The modern treatment revolution is biologic and small-molecule therapy: 5-ASAs (mesalamine for UC), corticosteroids (short-term flare control only), immunomodulators (azathioprine, methotrexate), TNF inhibitors (infliximab/Remicade, adalimumab/Humira), integrin antagonists (vedolizumab/Entyvio), IL-12/23 inhibitors (ustekinumab/Stelara, risankizumab/Skyrizi), and JAK inhibitors (tofacitinib, upadacitinib). These are genuinely transformative — biologic-era outcomes have dramatically reduced surgery rates, steroid dependence, and hospitalizations. This protocol is an ADJUNCTIVE supplement layer for adults with an established IBD diagnosis under gastroenterology care — NOT a substitute for proper medical therapy. It targets: nutrient deficiencies common in IBD due to malabsorption and inflammation (vitamin D, iron, B12), gut barrier support (L-glutamine), and inflammation modulation (omega-3 EPA, curcumin). Trial evidence is strongest for curcumin (Lang 2015 — curcumin + mesalamine outperformed mesalamine alone in UC remission) and vitamin D normalization (Ananthakrishnan 2013 — associated with reduced surgery risk in Crohn''s). CRITICAL: Beware "IBD cure" marketing. There is a substantial ecosystem promising that diet alone, supplements alone, or "leaky gut protocols" can reverse IBD. The honest evidence: supplements + diet measurably help but do NOT replace biologics or immunomodulators in moderate-to-severe disease. Stopping a biologic based on supplement marketing is one of the most reliable ways to lose intestinal tissue.
Trimester 3 Prenatal
maternal
Weeks 28 to delivery is the home stretch — and nutritionally the most demanding window of pregnancy. Roughly 60% of total fetal brain DHA accumulation happens in trimester 3, iron demand peaks as maternal blood volume and fetal stores complete loading, and the body is preparing for labor, delivery, and the first weeks of breastfeeding. This protocol covers five priorities: continuing a methylated prenatal, iron when ferritin is confirmed low (very common in T3 — many women need supplementation here even if they didn''t earlier), DHA-dominant omega-3 (T3 evidence is stronger than T1/T2 for infant outcomes), magnesium glycinate for the classic T3 trio of leg cramps + sleep disruption + constipation, and a late-pregnancy probiotic for potential infant eczema prevention. Coordinate every supplement with your OB and your hospital''s birth plan. T3 is also when GBS (Group B Strep) screening happens at 35-37 weeks, gestational diabetes monitoring intensifies, and you should be finalizing your delivery and early-postpartum plan. Supplements are one piece — sleep position, birth education, and postpartum support matter at least as much.
Trimester 2 Prenatal
maternal
The second trimester (weeks 14-27) is often described as the "honeymoon" of pregnancy — most morning sickness has resolved by weeks 14-16, energy returns, and the appetite usually improves. Underneath that subjective ease, however, the nutritional demand curve is accelerating sharply: maternal blood volume expands by roughly 40-50%, fetal growth shifts from organogenesis to rapid tissue accretion, and the placenta is now actively pulling iron, calcium, choline, and DHA across the maternal circulation. Iron requirements roughly double in the second half of pregnancy, and many women whose ferritin was adequate in T1 will become deficient by T2 — which is why ferritin re-checks at the 20-week visit matter. This protocol covers the five nutritional priorities for trimester 2: continuing the methylfolate-containing prenatal, supplemental iron paired with vitamin C (most prenatals under-dose iron for this window), choline at the full 450 mg/day target (commonly missed in generic prenatals), DHA-dominant omega-3 (fetal brain DHA accumulation accelerates in T2-T3), and calcium citrate if dietary intake is genuinely low. Coordinate every change with your OB — the anatomy scan at 18-22 weeks and the gestational diabetes screen at 24-28 weeks are key checkpoints where supplement adjustments are commonly made.
Stubborn Weight Loss Plateau
weight
Weight loss plateaus 8-12 weeks into a deficit are physiologically expected — metabolic adaptation lowers resting energy expenditure, and the original deficit erodes as body weight decreases. The honest answer to most plateaus is "the deficit is no longer a deficit." Before any supplement, audit calorie intake (often crept up by 200-300 kcal) and movement (often dropped). Subclinical micronutrient deficiencies (B12, iron, iodine) can also blunt energy levels and motivation. This stack addresses the residual after honest auditing — B-complex for energy, iodine (carefully) for thyroid support if low, tyrosine for stress-related plateaus, alpha-lipoic acid for insulin sensitivity. Mostly a nutrient-correction protocol, not a fat-loss amplifier.
Chronic Fatigue Recovery
energy
Persistent fatigue lasting 6+ months — distinct from temporary tiredness — affects roughly 25% of primary care visits and is one of the most under-diagnosed symptom clusters in medicine. The differential diagnosis is wide: anemia, hypothyroidism, sleep apnea, depression, chronic infections, mitochondrial dysfunction, post-viral syndromes (ME/CFS, Long COVID), early autoimmune disease. This protocol is for ADJUNCTIVE support after appropriate medical workup — supplements complement proper diagnostic workup and treatment of underlying causes. CoQ10 and NAD+ precursors (NMN or NR) target mitochondrial function (a documented finding in many chronic fatigue states); iron and B12 correct common reversible deficiencies; magnesium supports the multiple systems affected by chronic fatigue. If you have persistent unexplained fatigue, please see a doctor BEFORE relying on supplementation alone. The labs that should be done first: CBC, ferritin, TSH/free T4/T3, vitamin B12, vitamin D, fasting glucose, HbA1c, lipid panel, hsCRP, ESR, and consideration of further workup based on symptoms.
Food sources
| Food | Amount | %DV |
|---|---|---|
| Beef liver | 3 oz | 28% |
| Oysters | 3 oz | 44% |
| Fortified breakfast cereal | 1 serving | 100% |
| Beef (lean) | 3 oz | 12% |
| Spinach (cooked) | 1/2 cup | 17% |
| Lentils | 1/2 cup | 17% |
| Tofu | 1/2 cup | 19% |
Beef liver
- Amount
- 3 oz
- %DV
- 28%
Oysters
- Amount
- 3 oz
- %DV
- 44%
Fortified breakfast cereal
- Amount
- 1 serving
- %DV
- 100%
Beef (lean)
- Amount
- 3 oz
- %DV
- 12%
Spinach (cooked)
- Amount
- 1/2 cup
- %DV
- 17%
Lentils
- Amount
- 1/2 cup
- %DV
- 17%
Tofu
- Amount
- 1/2 cup
- %DV
- 19%
Choosing a product
What to look for on the label — and what to be skeptical of.
Look for…
Be skeptical of…
Frequently asked questions
Should I take iron supplements?⌄
Only if you have iron deficiency (confirmed by blood test) or are in a high-risk group (menstruating women with heavy periods, pregnancy, vegetarians/vegans, frequent blood donors). Test before supplementing - excess iron is harmful.
Why does iron upset my stomach?⌄
Iron irritates the gut lining. Try ferrous bisglycinate (chelated), take with a small amount of food, take every other day instead of daily, or split the dose.
What blocks iron absorption?⌄
Coffee, tea (tannins), calcium, antacids, dairy, eggs, whole grains (phytate), and some medications. Take iron 1-2 hours away from these.
What helps iron absorption?⌄
Vitamin C (orange juice, kiwi, strawberries), heme iron from animal sources (eaten alongside non-heme iron), and an empty stomach (if tolerable).
References by claim
iron deficiency anemia
exercise performance in iron deficiency
Safety
NIH Office of Dietary Supplements — Iron — NIH ODS link
Track Iron with Pilora
Set up dose reminders, check interactions, and join the community in the Pilora iPhone app.
Coming to App StoreDisclaimer: These statements have not been evaluated by the FDA. This page is educational, not a substitute for personalized medical advice. Evidence grades are AI-assisted assessments — talk to your doctor before starting any new supplement, especially if you’re pregnant, breastfeeding, on medications, or managing a chronic condition.