How to choose
Get tested first. Because too much iron is harmful and the symptoms of low iron overlap with many other things, a ferritin blood test is the honest starting point. If you do need iron, focus on the elemental iron per dose, choose a gentler form (like ferrous bisglycinate) if your stomach is sensitive, and take it for absorption — with vitamin C, away from calcium, coffee, and tea. See our guide to the best time to take iron and iron supplements.
Emerging evidence supports every-other-day dosing for many people — similar benefit with fewer side effects. Confirm third-party testing and run any product through the Supplement Trust Scorecard. Iron isn't right for everyone, so check with a clinician, especially in pregnancy or with a health condition.
Frequently asked questions
Which iron supplement is easiest on the stomach?
Ferrous bisglycinate and lower elemental-iron doses tend to be gentler than high-dose ferrous sulfate, which commonly causes constipation, nausea, and cramping. Taking iron every other day, or with food (accepting slightly lower absorption), can also reduce side effects.
Should women take iron every day?
Not unless they need it. Iron supplements are for treating or preventing a diagnosed deficiency, not a routine 'just in case.' Research also suggests every-other-day dosing can absorb as well as daily dosing with fewer side effects. A ferritin test and a clinician's advice should guide it.
What helps iron absorb better?
Vitamin C (like a glass of orange juice) boosts absorption, while calcium, coffee, and tea reduce it — so space iron away from them. Taking iron on a relatively empty stomach absorbs best but can be harder on the gut.