NutriStack
Allopurinol and Iron, a caution.
The interaction between allopurinol and iron is primarily theoretical. In animal studies, allopurinol increased hepatic iron storage by inhibiting the ferritin-xanthine oxidase system responsible for iron mobilization from the liver. However, controlled human studies found no measurable effect of allopurinol on iron absorption, storage, or red cell incorporation. A reversible rise in serum iron with decreased iron-binding capacity was observed at high doses (500-600 mg/day) but normalized at standard doses (300 mg/day).
One pair, every claim cited. The two substances, the type, the mechanism, the recommendation, and the primary literature.
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What the row says.
Every entry follows the same shape: what is happening, the mechanism, the recommendation, and the primary literature.
At a glance
- Substances
- Allopurinol and Iron
- Pair type
- Caution
- Evidence (highest tier)
- Emerging
- Source citations
- 6 sources
- Stack Score effect
- −5 to your Stack Score (per scored caution row).
- Scope
- Supplement × Prescription
- Last verified
- May 30, 2026
Caution · Emerging evidence
Caution
What is happening. The interaction between allopurinol and iron is primarily theoretical. In animal studies, allopurinol increased hepatic iron storage by inhibiting the ferritin-xanthine oxidase system responsible for iron mobilization from the liver. However, controlled human studies found no measurable effect of allopurinol on iron absorption, storage, or red cell incorporation. A reversible rise in serum iron with decreased iron-binding capacity was observed at high doses (500-600 mg/day) but normalized at standard doses (300 mg/day).
Mechanism. Xanthine oxidase participates in iron mobilization from hepatic ferritin stores. Allopurinol inhibits xanthine oxidase, which theoretically could impair iron release from storage. In animal models, this led to increased hepatic iron deposition. In humans, the effect appears clinically insignificant at standard doses, possibly due to alternative iron mobilization pathways.
Recommendation. Standard iron supplementation is generally safe with allopurinol at typical doses (100-300 mg/day). If taking high-dose allopurinol (>300 mg/day), periodic monitoring of serum iron and ferritin may be prudent. No timing separation is typically needed. Inform your prescriber about concurrent iron supplementation.
Sources (6)
- Powell LW, Emmerson BT. Effect of allopurinol on iron mobilization. Gastroenterology. 1966;51:631-636. PMID 5927996
- Davis PS, Deller DJ. Allopurinol and iron metabolism in man. Blood. 1968;32(3):460-469. PMID 5681113
- Fischer JAJ, Cherian AM, Bone JN, Karakochuk CD. The effects of oral ferrous bisglycinate supplementation on hemoglobin and ferritin concentrations in adults and children: a systematic review and meta-analysis of randomized controlled trials. Nutrition Reviews. 2023. PMID 36728680
- Rehman T, Agrawal R, Ahamed F et al.. Optimal dose and duration of iron supplementation for treating iron deficiency anaemia in children and adolescents: A systematic review and meta-analysis. PLoS One. 2025. PMID 39951396
- Gutema BT, Sorrie MB, Megersa ND et al.. Effects of iron supplementation on cognitive development in school-age children: Systematic review and meta-analysis. PLoS One. 2023. PMID 37368919
- Hansen R, Sejer EPF, Holm C, Schroll JB. Iron supplements in pregnant women with normal iron status: A systematic review and meta-analysis. Acta Obstetricia et Gynecologica Scandinavica. 2023. PMID 37403900
Stack Score
How this pair moves the number.
Effect on the composite score
If both Allopurinol and Iron are in the same stack, this pair applies −5 to your Stack Score (per scored caution row).
The full algorithm, the clamping rules, and four worked stacks are documented at /methodology/stack-score.
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