Iron: which form, what each one does, and the dose that worked
Iron comes in many forms, and what it does depends on the form. Every result below names the form it came from. Pick the form you take to see its own studies, products and what the biohackers say about it. This page is educational, not medical advice.
What it does, by goalMembersThe top 5 of 13 goals
2 of these 46 human studies gave iron by drip, not by mouth.
| Goal | What the studies show | Studies | Dose that worked |
|---|---|---|---|
| Improved in studies Ferrous sulfate: 4 of 6 improved, 1 no effect | 6 | ferrous sulfate 300 mg | |
| Improved in studies Ferrous gluconate: 1 of 4 improved, 1 no effect · Bisglycinate: 1 of 2 improved · Heme iron: 1 of 1 improved · Ferrous sulfate: 4, all no effect · Ferrous fumarate: 2, both no effect · 1 by drip, injection or inhaler | 13 | ferrous gluconate 75 mg · bisglycinate 24 mg | |
| Improved in studies Ferrous gluconate: 1 of 2 improved · Bisglycinate: 1 of 1 improved · Ferrous sulfate: 2 studies, 1 no effect · 1 by drip, injection or inhaler | 5 | ferrous gluconate 15 mg · bisglycinate 24 mg | |
| Improved in studies Ferrous sulfate: 2 of 3 improved · Ferrous fumarate: 1 study, no clear result | 4 | ferrous sulfate 80 mg | |
| Improved in studies Heme iron: 1 of 3 improved | 3 | – | |
| Improved in studies Ferrous sulfate: 1 of 1 improved · Polysaccharide iron: 2, both no effect | 3 | ferrous sulfate 600 mg | |
| Too few studies Ferrous sulfate: 1 of 3 improved, 1 no effect | 3 | ferrous sulfate 325 mg | |
| Too few studies Ferrous sulfate: 2, both no effect · Ferrous fumarate: 1 study, no clear result · 1 by drip, injection or inhaler | 3 | – | |
| Too few studies Ferrous sulfate: 2 studies, 1 no effect | 2 | – | |
| Too few studies Ferrous sulfate: 2 studies, no clear result | 2 | – | |
| Too few studies Ferrous sulfate: 1 study, no clear result | 1 | – | |
| Too few studies Heme iron: 1 study, no clear result | 1 | – | |
| No effect in studies Ferrous sulfate: 1 of 3 improved, 1 no effect | 3 | ferrous sulfate 7.5 mg |
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Products – highest ranked firstMembersThe top 3 of 23
Dose and safetyThe dose that worked and the upper limit
The doses that worked, by form, in the studies taken by mouth: bisglycinate 24 mg, ferrous sulfate 7.5 to 600 mg, ferrous gluconate 15 to 75 mg, heme iron 18 mg a day.
The upper limit for adults is 45 mg of iron a day, counted as the iron itself, not the weight of the compound; above it, members see a note and are told they can take less.
Biohacker panelMembersWhich forms of iron our 10 biohackers name
Members see which forms the panel backs, and what each biohacker said. Start My 7-Day Free Trial →
Questions people askMembersAnswered from the figures on this page
Which form of iron is best?
Answer for members.
How much iron a day?
Answer for members.
Can I take iron with my meds?
Answer for members.
Members see the answers, checked against their own meds and goals. Start My 7-Day Free Trial →
Educational, not medical advice. Figures come from the human studies on PubMed we have graded; a study counts for a form when it names the form it used. Updated as new studies arrive. How we grade →