Loading…
Also known as Ferrous sulfate, Ferrous bisglycinate
Essential mineral forming the oxygen-binding core of haemoglobin and myoglobin; supplementation corrects iron-deficiency anaemia, a common cause of fatigue, particularly in menstruating women.
We link to relevant studies and leave interpretation to you and your healthcare professional.
Number of audited published findings for Iron by condition. Drill into a pair page for the full breakdown.
Where people report using it and what trials suggest
Common claims the trials do not support
Essential mineral with high-supplement risk if not deficient — testing before supplementing matters more than with most supplements.
Safety notes: Overdose is a leading paediatric poisoning risk. Screen for haemochromatosis. Constipation common; alternate-day dosing improves absorption.
Evidence grades reflect study quality and consistency, not marketing claims.
Summaries of published trial results for this compound, grouped by condition. Numbers are reported exactly as the researchers published them — we never calculate or convert.
How to read this table
In short: benefit is what was observed; evidence is how much you should trust the observation. A “Benefit seen” tag on a weak study counts for far less than the same tag on a meta-analysis.
| Outcome measured | What trials found | Effect size | People studied | Duration | Type of evidence | Study |
|---|---|---|---|---|---|---|
| maximal oxygen consumption | Iron supplementation showed no significant difference in maximal oxygen consumption compared to placebo or active therapy in 235 participants. (95% CI -0.15 to 0.37)No clear benefit | no number reported | 235 | — | Systematic review · 2018 | PMID 29626044 |
| self-reported fatigue | Iron supplementation reduced self-reported fatigue (SMD -0.38) compared to placebo or active therapy in 714 participants. (95% CI -0.52 to -0.23)Benefit seen | -0.38 SMD | 714 | — | Systematic review · 2018 | PMID 29626044 |
Associated conditions and community-reported outcomes, wrapped together on one page. Aggregates appear only once enough reports arrive.
How this compound is sold in the UK, and where our readers typically find it.
Retailer search links — we may earn commission on purchases at no cost to you. Commission never affects our evidence ratings.
| serum ferritin | Iron supplementation increased serum ferritin by 9.23 µmol/L compared to placebo or active therapy in 616 participants. (95% CI 6.48 to 11.97)Benefit seen | 9.23 µmol/L | 616 | — | Systematic review · 2018 | PMID 29626044 |
| serum haemoglobin concentration | Iron supplementation increased serum haemoglobin by 4.01 g/L compared to placebo or active therapy in 298 participants. (95% CI 1.22 to 6.81)Benefit seen | 4.01 g/L | 298 | — | Systematic review · 2018 | PMID 29626044 |
| timed methods of exercise testing | Iron supplementation showed no significant difference in timed exercise testing compared to placebo or active therapy.No clear benefit | no number reported | — | — | Systematic review · 2018 | PMID 29626044 |