Best Iron Supplements for Pregnancy 2026: Safe and Gentle Options
NOW Foods Iron 18mg Ferrochel is the best additional iron supplement for pregnancy — gentle chelated form minimizes GI side effects that compound pregnancy nausea, and the 18mg dose supplements the iron already present in most prenatal vitamins. Work with your OB to determine if additional supplementation is needed beyond your prenatal vitamin.
See Today’s Price →At a Glance
Iron Supplements for Pregnancy Buying Guide
Photo by Mateusz Dach / PexelsGreat for: Pregnant women — iron requirements nearly double during pregnancy, and bisglycinate forms like NOW Foods 18mg ($8.70) are recommended for prenatal use due to lower GI side effects
Not ideal if: You haven't discussed dosing with your OB — prenatal iron requirements vary based on hemoglobin levels and prenatal vitamin iron content
Iron Needs During Pregnancy
How we picked these. We reviewed 5 iron supplements for pregnancy across safety-certified iron form (ferrous bisglycinate), elemental iron meeting prenatal guidelines, methylfolate co-inclusion, third-party testing certification, and nausea tolerability in the first trimester, cross-referencing picks from OB-GYN guidance, Examine.com, and NIH prenatal nutrition research. Products were selected for prenatal safety and iron bioavailability at each price point.
Iron requirements jump from 18mg to 27mg per day during pregnancy. Most prenatal vitamins contain 27-30mg iron, but many pregnant women — especially those who start pregnancy with depleted iron stores — need additional supplementation. The American College of Obstetricians and Gynecologists recommends testing ferritin at the first prenatal visit and again at 24-28 weeks. About 40-50% of pregnant women become iron deficient even with prenatal vitamins.
Pregnancy Nausea and Iron Supplementation
Iron is one of the most common reasons pregnant women stop taking prenatal vitamins — the iron content worsens nausea and causes constipation during a period when nausea is already severe. Solutions: (1) Switch to a prenatal with iron bisglycinate instead of ferrous sulfate; (2) Add a separate gentle iron supplement at night when nausea is typically lower; (3) Take iron with a small snack to reduce nausea while accepting modest absorption reduction.
Iron and Fetal Development
Iron is critical for fetal brain development — the brain has its highest iron demands during the third trimester and first year of life. Maternal iron deficiency during pregnancy is associated with preterm birth, low birth weight, and impaired infant cognitive development. Adequate iron supplementation protects both maternal health and fetal neurodevelopment.
Postpartum Iron Replenishment
Childbirth typically involves 300-500mL blood loss (up to 1000mL in complicated deliveries), significantly depleting iron stores. Many women enter the postpartum period significantly iron-deficient, contributing to postpartum fatigue and depression. Continue iron supplementation for 6-12 weeks postpartum and retest ferritin levels. Breastfeeding iron needs drop to 9mg/day, so supplementation can typically be reduced.
Related Guides
Our Picks
NOW Foods Iron 18mg Non-Constipating Ferrochel 120 Capsules (Best Overall) — $8 See Price →
Thorne Iron Bisglycinate 25mg 60 Capsules (Best Premium Pregnancy Option) — $16 See Price →
Botanic Choice Iron 18mg Bisglycinate Chelate (Best Value for Pregnancy Use) — $11 See Price →
Showing 3 of 3 products
NOW Foods Iron 18mg Non-Constipating Ferrochel 120 Capsules
“The best iron supplement for those who need long-term daily iron maintenance without GI discomfort. Ferrous bisglycinate's gentle tolerability is the reason it's preferred over ferrous sulfate for reg”
See Today’s Price →What we like
- Ferrous bisglycinate — gentlest, best-tolerated iron form
- 18mg matches daily RDA for menstruating women
- 30,000+ Amazon reviews
- NOW Foods is a trusted supplement brand
- Vegan capsules
Watch out for
- 18mg dose may be too low for correcting significant deficiency — therapeutic doses are often 100-200mg elemental iron under medical supervision
- No added vitamin C cofactor in this formula
Read Full Analysis
NOW Foods Iron 18mg Ferrochel is the top additional iron supplement for pregnant women — specifically labeled non-constipating, using the gentlest chelated form, at a dose that supplements (not duplicates) the iron in prenatal vitamins. Best for: pregnant women whose prenatal vitamin doesn't fully meet iron needs or who need additional supplementation per their OB.
Thorne Iron Bisglycinate 25mg 60 Capsules
“The best tolerated iron supplement for runners — bisglycinate form prevents the GI distress that causes most people to stop taking iron.”
See Today’s Price →What we like
- Bisglycinate form is gentler than ferrous sulfate
- Thorne is NSF Certified for Sport
- No artificial fillers or additives
- 25mg is a therapeutic but not excessive dose
Watch out for
- More expensive than basic iron supplements
- Should confirm deficiency with bloodwork first
Read Full Analysis
Thorne Iron Bisglycinate 25mg is NSF Certified for Sport — among the highest quality standards in supplement manufacturing. Thorne is used by many healthcare practitioners for pregnancy supplementation. Best for: pregnant women whose physician recommends higher-dose iron supplementation with verified product quality.
Botanic Choice Iron 18mg Bisglycinate Chelate
“The best choice for those who prefer a natural supplement brand for their iron. Botanic Choice's 100+ year track record in mineral supplementation provides assurance that their iron sourcing and quali”
See Today’s Price →What we like
- Iron supplement from natural supplement brand since 1910
- Mineral quality standards from century of supplement expertise
- Affordable at $11.99
- Tablet form with precise dosing
- No artificial additives or fillers
Watch out for
- Less Amazon review history than major brands
- Iron form not specified — check label for bisglycinate vs. sulfate
Read Full Analysis
Botanic Choice Iron 18mg Bisglycinate Chelate provides pregnancy-appropriate gentle iron at the most affordable price in this roundup. Best for: pregnant women on a budget who need additional iron supplementation beyond their prenatal vitamin.
Frequently Asked Questions
Is iron bisglycinate safe during pregnancy?
How much additional iron do I need if my prenatal has iron?
Can iron supplements cause miscarriage?
Should I take iron supplements in the first trimester?
Can I take iron supplements while breastfeeding?
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