Can you take Caffeine and Iron (ferrous bisglycinate) together?
Yes, with care — this combination needs a precaution.
Caffeine and Iron (ferrous bisglycinate) can be taken together, but the combination needs a precaution.
Why these two interactSources for why these two interact: Jumps to this entry in the sources and references list at the end of the page.
Polyphenols in coffee/tea inhibit non-heme iron absorption by up to 60%.
Inferred from a shared mechanism, not documented for this specific pair. The same explanation is applied to other combinations that work the same way.
What to do about itSources for what to do about it: Jumps to this entry in the sources and references list at the end of the page.
Take iron away from coffee and tea by at least 2 hours.
TimingSources for timing: Jumps to this entry in the sources and references list at the end of the page.
Separate Caffeine and Iron (ferrous bisglycinate) by at least 2 hours. Taking them in the same window is what causes the issue, not taking them on the same day.
The two items in this pair
Caffeine
- Category:
- supplement
- Typical timing:
- morning
- With food:
- either
- Half-life:
- 5 h
Iron (ferrous bisglycinate)
- Category:
- mineral
- Typical timing:
- morning
- With food:
- either
Check your whole routine, not just this pair
One pair rarely tells the whole story. DoseRoutine checks every combination in your stack at once — supplements, TRT, peptides, GLP-1s and prescriptions — and schedules the doses so timing conflicts like this one are handled automatically.
Frequently asked
Sources cited on this page
Specific documents referenced by the numbered markers above.
- Inhibition of non-haem iron absorption in man by polyphenolic-containing beverages(opens in a new tab)PubMed — National Library of Medicine · pubmed.ncbi.nlm.nih.gov/10999016/
- Effect of tea and other dietary factors on iron absorption(opens in a new tab)PubMed — National Library of Medicine · pubmed.ncbi.nlm.nih.gov/11029010/
- Iron — Fact Sheet for Health Professionals(opens in a new tab)NIH Office of Dietary Supplements · ods.od.nih.gov/factsheets/Iron-HealthProfessional/
Verify at
This assessment is mechanism-based. These publisher search links let you check it against the current evidence — they are not citations, so they are not numbered.
- PubMed: Caffeine + Iron (ferrous bisglycinate)(publisher search, opens in a new tab)National Library of Medicine · publisher search
- DailyMed label: Caffeine(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- DailyMed label: Iron (ferrous bisglycinate)(publisher search, opens in a new tab)U.S. National Library of Medicine · publisher search
- Cochrane Library(publisher search, opens in a new tab)Cochrane · publisher search
Related combinations
- Amantadine and CaffeineCaution
- Amphetamine Salts and CaffeineCaution
- Caffeine and Creatine MonohydrateNote
- Caffeine and L-TheanineComplementary
- Caffeine and LisdexamfetamineCaution
- Caffeine and MethylphenidateCaution
- Calcium and Iron (ferrous bisglycinate)Caution
- Iron (ferrous bisglycinate) and LevothyroxineCaution
Educational information only, not medical advice. DoseRoutine does not diagnose or treat. Talk to your prescriber before starting, stopping or combining anything — especially if you take prescription medication or are pregnant or breastfeeding.