Is iron worth taking for tiredness if you're not anaemic?

Iron can meaningfully reduce fatigue even without anaemia, but mainly when ferritin (iron stores) is low. A randomised trial of 144 non-anaemic women with unexplained tiredness found that those taking 80 mg elemental iron daily for four weeks saw their fatigue score drop notably more than those on placebo — particularly among women whose ferritin was ≤20 µg/L 1.

The practical takeaway: it's the iron-store level, not the haemoglobin (the anaemia marker), that seems to matter most. Women with low-normal or depleted ferritin appeared to get the most benefit 1. For people with genuinely normal stores, the evidence doesn't support supplementing — and iron taken without a real deficiency can cause harm, including iron overload.

A few things worth knowing before trying it:

• Get ferritin tested first — that's the number that determines whether this is likely to help
• Common side effects include constipation, nausea, and dark stools
• Take it in the morning on an empty stomach with vitamin C, away from tea, coffee, and calcium