The short answer
Iron supplements may interfere with raltegravir absorption, but an exact iron-specific effect has not been quantified in the sources reviewed. U.S. NIH guidance recommends taking raltegravir at least 2 hours before or 6 hours after necessary mineral supplements, with treatment-response monitoring. Confirm the schedule with your HIV pharmacist.
What this answer covers
Adult oral raltegravir tablets and oral iron supplements. Advice is based on potential polyvalent-mineral binding and exact-drug guidelines, not a retrieved isolated-iron pharmacokinetic or virologic outcome trial.
- Supplement or preparation
- Iron
- Medication ingredient
- raltegravir
Why is iron included in interaction guidance?
Raltegravir can interact with polyvalent minerals in the digestive tract. Iron is included in the NIH supplement guidance because binding may reduce the amount of HIV medicine absorbed. The directly inspected label studies concern antacids, rather than a stand-alone iron supplement trial. That distinction matters: a precaution for iron should not be described as a measured percentage reduction in raltegravir levels or as inevitable loss of viral suppression.
Which timing recommendation should I use?
U.S. NIH guidance advises raltegravir at least two hours before or six hours after a necessary polyvalent mineral supplement, with virologic monitoring. UK specialist guidance for 400 mg raltegravir uses a two-hour interval either side for iron. These recommendations differ, and neither is a direct comparison proving an ideal iron schedule. Your HIV pharmacist should reconcile the advice for your regimen rather than assuming any two-hour gap is equivalent.
Does an iron-containing multivitamin count?
Iron may be supplied alone, in a prenatal product or in a multivitamin that also contains calcium, magnesium or zinc. The complete mixture needs review because different ingredients can bring different instructions. The amount stated as an iron salt is not the same as elemental iron. No specific ferrous salt or daily iron dose was established as universally safe with raltegravir in the sources reviewed.
How can I manage prescribed iron treatment?
Tell your HIV team why you need iron and bring the product label, amount and usual dose times. A pharmacist can build a schedule that preserves both treatments and plan appropriate viral-load follow-up. Do not stop raltegravir or adjust its dose on your own. If iron causes stomach problems or the proposed gap is difficult to maintain, ask for the schedule to be reviewed rather than abandoning either medicine.
Evidence and practical considerations
Absorption & effectiveness
Iron supplements may interfere with raltegravir absorption, but an exact iron-specific effect has not been quantified in the sources reviewed. U.S. NIH guidance recommends taking raltegravir at least 2 hours before or 6 hours after necessary mineral supplements, with treatment-response monitoring. Confirm the schedule with your HIV pharmacist.
- Exact scope
- Adult oral raltegravir tablets and oral iron supplements. Advice is based on potential polyvalent-mineral binding and exact-drug guidelines, not a retrieved isolated-iron pharmacokinetic or virologic outcome trial. with Adult oral raltegravir tablets: Isentress 400 mg twice daily versus Isentress HD 1,200 mg once daily
- Medication form and route
- Adult oral raltegravir tablets: Isentress 400 mg twice daily versus Isentress HD 1,200 mg once daily; oral mineral, supplement or antacid within stated preparation scope
- Timing or duration
- Guidance applies during ongoing supplement use; no exact iron salt, dose or duration was established in a retrieved raltegravir-iron trial.
What remains uncertain
- Direct iron-specific evidence is limited. U.S. NIH and UK pharmacy timing recommendations differ. An order-independent two-hour interval is not a universal rule, and antacid studies cannot supply an iron-specific effect size.
Factors that may matter: Exact mineral ingredients, preparation and elemental amount; Isentress 400 mg twice daily versus Isentress HD 1,200 mg once daily; Food and direction of administration when applicable; Concurrent mineral products, adherence and viral-load monitoring.
Read the supporting source summaries
Source 1: current manufacturer U.S. regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People using oral raltegravir; adult 400 mg twice-daily Isentress and 1,200 mg once-daily Isentress HD regimens are distinguished.
Aluminum/magnesium antacids are not recommended even with staggered dosing. Calcium carbonate antacid requires no adjustment with 400 mg twice daily but is not recommended with 1,200 mg once daily. With the once-daily regimen, a 12-hour gap still left markedly reduced trough levels.
How this applies: Explicit salt-to-active-moiety bridge for exact RxNorm raltegravir. Each article preserves the 400 mg twice-daily versus 1,200 mg once-daily distinction and does not extend these tablet data to pediatric chewable tablets or suspension. Exact article scope: Adult oral raltegravir tablets and oral iron supplements. Advice is based on potential polyvalent-mineral binding and exact-drug guidelines, not a retrieved isolated-iron pharmacokinetic or virologic outcome trial.
The adult tablet regimens are not interchangeable. These exact antacid studies do not establish effects of all dietary mineral salts, zinc, iron or vitamin-only products. Healthy and HIV-positive study conditions differ; reductions in drug concentrations do not directly quantify treatment failures.
Source 2: U.S. expert clinical treatment guideline
clinicalinfo.hiv.gov · Source check Sep 10, 2026
Population: Adults and adolescents receiving integrase inhibitor regimens for HIV.
Bictegravir mineral directions depend on cation and food. If raltegravir must be used with polyvalent mineral supplements, give it at least 2 hours before or 6 hours after and monitor virologic response. Multivitamin chelation magnitude is uncertain. Raltegravir antacid rules are separate: avoid Al/Mg, and distinguish calcium carbonate 400 mg twice daily from 1,200 mg once daily. Do not coadminister bictegravir with St. John’s wort.
How this applies: Exact-drug management guidance. Bictegravir sodium and raltegravir potassium are interpreted through their labels’ active-moiety equivalents. Calcium/iron food exceptions for bictegravir do not transfer to raltegravir. Exact article scope: Adult oral raltegravir tablets and oral iron supplements. Advice is based on potential polyvalent-mineral binding and exact-drug guidelines, not a retrieved isolated-iron pharmacokinetic or virologic outcome trial.
Expert recommendations include predicted interactions where exact-pair clinical studies are absent. A suggested supplement schedule does not supersede the distinct antacid avoidance instructions. No universal safe dose or virologic risk percentage is established.
Source 3: specialist pharmacy patient guidance
hivpa.org · Source check Sep 10, 2026
Population: People prescribed Isentress 400 mg twice daily; UK pharmacy guidance.
Advises avoiding aluminum/magnesium antacids, four-hour separation either side for calcium/magnesium supplements and multivitamins, and two-hour separation either side for iron/zinc.
How this applies: Documents a genuine guideline difference so an existing two-hour suggestion is not described as wholly invented. The consumer article states its U.S. NIH basis and directs regimen-specific reconciliation with the HIV pharmacist. Exact article scope: Adult oral raltegravir tablets and oral iron supplements. Advice is based on potential polyvalent-mineral binding and exact-drug guidelines, not a retrieved isolated-iron pharmacokinetic or virologic outcome trial.
Patient guidance, not a comparative timing trial. The schedules differ from the U.S. NIH 2-hours-before/6-hours-after supplement recommendation. Its 400 mg scope does not establish instructions for Isentress HD 1,200 mg once daily. The 2026 URL folder is not the clinical review date.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current exact-drug labeling and guidance checked; original human studies and neutral findings assessed. Current statements adjudicated with formulation, food and directional timing corrections. Article written; clinical sign-off not recorded. | |
| Research summary published |
Article revision: 9b1565d6fd4b3b97
This guide brings together the evidence records used by our interaction checker. Each finding retains its own preparation limits, research date, and source summaries.
Full citations require verification. Reading this answer and the source summaries does not.
Taking other supplements or medications?
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Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.