The short answer
Not every multivitamin has been shown to reduce raltegravir levels. A small study of one product with a single 400 mg dose found no statistically significant change, but the results were too imprecise to cover all products or regimens. Mineral-containing multivitamins still need a product-specific timing review.
What this answer covers
Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
- Supplement or preparation
- Multivitamin
- Medication ingredient
- raltegravir
What did the direct multivitamin study find?
An original conference report tested a single 400 mg Isentress dose with one Forceval capsule without food. Among ten evaluable multivitamin observations, overall exposure and the 12-hour concentration were not statistically significantly different from raltegravir alone. However, the exposure confidence interval was very wide. The result offers limited information about that product, not proof that all multivitamins leave raltegravir unchanged.
Why is a mineral precaution still relevant?
Multivitamins can contain calcium, iron, magnesium, zinc or a mixture of these. NIH notes that the extent and significance of multivitamin binding interactions are uncertain and recommends caution with necessary polyvalent mineral supplements. The small neutral study does not override the separate antacid restrictions in the raltegravir label. Vitamins without relevant minerals should not automatically be treated as equivalent to a mineral-rich product.
What timing advice applies?
For necessary mineral supplements, U.S. NIH guidance places raltegravir at least two hours before or six hours after, with monitoring of virologic response. UK specialist guidance for 400 mg raltegravir recommends a different multivitamin interval. Neither supports a blanket instruction that every multivitamin must be six hours away in both directions. Ask your HIV pharmacist to specify the schedule for the ingredients and raltegravir formulation you actually use.
Does the study cover Isentress HD or prenatal vitamins?
No. The direct report tested one Forceval capsule with a single 400 mg dose, not the 1,200 mg once-daily regimen or every prenatal formula. It also measured concentrations rather than long-term HIV control. Bring the supplement facts panel and medication bottle to your review. Keep raltegravir on its prescribed schedule and resolve an inconvenient supplement plan with your pharmacist rather than changing the HIV dose.
Evidence and practical considerations
Absorption & effectiveness
Not every multivitamin has been shown to reduce raltegravir levels. A small study of one product with a single 400 mg dose found no statistically significant change, but the results were too imprecise to cover all products or regimens. Mineral-containing multivitamins still need a product-specific timing review.
- Exact scope
- Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily. 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
- Direct study used a single 400 mg dose with one Forceval capsule; only 10 evaluable multivitamin observations. Chronic coadministration and virologic outcomes were not established.
What remains uncertain
- Small conference report with wide confidence intervals. Neutral statistical findings do not prove equivalence, and ingredient-specific guidance remains relevant. A blanket six-hour rule for all multivitamins is not supported.
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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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: original prospective human pharmacokinetic conference report
croiconference.org · Source check Sep 10, 2026
Population: 15 healthy adults randomized, with 14 evaluable raltegravir-alone observations and 10 evaluable multivitamin observations after withdrawals.
Forceval coadministration produced exposure ratio 0.83 (90% CI 0.33-2.08), 12-hour concentration ratio 0.90 (0.60-1.35), and peak ratio 0.88 (0.32-2.38). None was statistically significantly different from raltegravir alone.
How this applies: Direct neutral evidence for the specific Forceval product with single-dose 400 mg raltegravir. It must not be expanded to all prenatal, mineral-rich or once-daily raltegravir combinations. Exact article scope: Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
Conference poster, not a peer-reviewed full journal report. Very wide confidence intervals and only 10 multivitamin observations do not establish equivalence. One product and single 400 mg dose; no 1,200 mg regimen, chronic clinical outcomes or universal multivitamin timing. Supported by an MSD investigator grant and study drug.
Source 4: 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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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 ↗
Absorption & effectiveness
One Forceval capsule with a single 400 mg raltegravir dose did not significantly alter exposure in ten evaluable healthy participants. Wide confidence intervals and the specific product and regimen prevent an all-multivitamin equivalence conclusion.
- Exact scope
- Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily. 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
- Direct study used a single 400 mg dose with one Forceval capsule; only 10 evaluable multivitamin observations. Chronic coadministration and virologic outcomes were not established.
What remains uncertain
- Small conference report with wide confidence intervals. Neutral statistical findings do not prove equivalence, and ingredient-specific guidance remains relevant. A blanket six-hour rule for all multivitamins is not supported.
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: original prospective human pharmacokinetic conference report
croiconference.org · Source check Sep 10, 2026
Population: 15 healthy adults randomized, with 14 evaluable raltegravir-alone observations and 10 evaluable multivitamin observations after withdrawals.
Forceval coadministration produced exposure ratio 0.83 (90% CI 0.33-2.08), 12-hour concentration ratio 0.90 (0.60-1.35), and peak ratio 0.88 (0.32-2.38). None was statistically significantly different from raltegravir alone.
How this applies: Direct neutral evidence for the specific Forceval product with single-dose 400 mg raltegravir. It must not be expanded to all prenatal, mineral-rich or once-daily raltegravir combinations. Exact article scope: Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
Conference poster, not a peer-reviewed full journal report. Very wide confidence intervals and only 10 multivitamin observations do not establish equivalence. One product and single 400 mg dose; no 1,200 mg regimen, chronic clinical outcomes or universal multivitamin timing. Supported by an MSD investigator grant and study drug.
Research assessment: · Open full citations ↗
Timing & monitoring
For necessary polyvalent mineral supplements, NIH recommends raltegravir at least 2 hours before or 6 hours after, with virologic monitoring. This is guidance rather than proof that every multivitamin interacts; antacid restrictions and formulation distinctions still apply.
- Exact scope
- Adult oral raltegravir tablets and multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily. 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
- Direct study used a single 400 mg dose with one Forceval capsule; only 10 evaluable multivitamin observations. Chronic coadministration and virologic outcomes were not established.
What remains uncertain
- Small conference report with wide confidence intervals. Neutral statistical findings do not prove equivalence, and ingredient-specific guidance remains relevant. A blanket six-hour rule for all multivitamins is not supported.
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: 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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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 2: 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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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 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 multivitamin products. Direct neutral evidence concerns one Forceval capsule with a single Isentress 400 mg dose fasting; it does not establish equivalence for prenatal products, other mixtures or Isentress HD 1,200 mg once daily.
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: 3dfbd32b9529ffc3
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?
Use the checker to explore your other combinations. Ask a pharmacist to review the exact products, amounts and medical conditions in your complete list.
Open the interaction checkerInformation, not medical advice. Do not change prescribed treatment based on this guide.