The short answer
Calcium supplements can be used with dolutegravir when the schedule follows the product instructions. For TIVICAY tablets, calcium may be taken at the same time with food. When fasting, take dolutegravir at least two hours before or six hours after the supplement.
What this answer covers
Oral dolutegravir tablets with calcium supplements. The controlled experiment used calcium carbonate; instructions for calcium antacids and other components of combination HIV tablets must be checked separately.
- Supplement or preparation
- calcium
- Medication ingredient
- dolutegravir
Why is timing important?
A study enrolled twenty-four healthy adults into calcium or iron groups. Calcium carbonate taken with fasting dolutegravir lowered total drug exposure by about 39%. The tested 1,200 mg calcium-carbonate amount supplied about 480 mg elemental calcium, so the two numbers should not be confused.
What did food or spacing change?
The study tested a moderate-fat meal and a schedule with dolutegravir two hours before calcium. Both counteracted the decrease seen during simultaneous fasting administration. It did not study long-term viral suppression or directly compare every possible separation interval.
What schedule should I use?
The current TIVICAY instructions allow calcium supplements together with food. If fasting, the two-hours-before or six-hours-after instruction applies to dolutegravir. Check whether your product is a supplement, an antacid or a combination HIV medicine; a calcium rule alone does not cover the whole regimen.
Does this apply to every calcium dose?
The label gives general calcium-supplement instructions, but the experiment did not measure every salt or dose. Show the pharmacist the elemental amount and any added iron, magnesium or zinc. There is no reason to change your prescribed HIV dose yourself to offset a supplement.
Evidence and practical considerations
Absorption & effectiveness
Calcium supplements can be used with dolutegravir when the schedule follows the product instructions. For TIVICAY tablets, calcium may be taken at the same time with food. When fasting, take dolutegravir at least two hours before or six hours after the supplement.
- Exact scope
- Oral dolutegravir tablets with calcium supplements. The controlled experiment used calcium carbonate; instructions for calcium antacids and other components of combination HIV tablets must be checked separately. with Dolutegravir, exact RxCUI 1433868, IN. TIVICAY contains dolutegravir sodium expressed as dolutegravir active-moiety strength in its label. This provides the explicit salt-to-IN bridge. Oral tablets are the primary scope; no automatic extrapolation to another integrase inhibitor or a different combination regimen. TIVICAY PD is not interchangeable milligram for milligram.
- Medication form and route
- oral
What remains uncertain
- Single-dose healthy-adult pharmacokinetics using one calcium salt and dose. Broader labeled scheduling does not imply the same numerical effect for every product or a proven rate of treatment failure.
Factors that may matter: exact preparation and dose; food and administration order; complete antiretroviral regimen.
Read the supporting source summaries
Source 1: regulatory prescribing information
dailymed.nlm.nih.gov · Source check Sep 10, 2026
Population: People prescribed oral dolutegravir, including tablet and pediatric suspension formulations with separate dosing instructions.
Specifies dolutegravir two hours before or six hours after named mineral products; calcium/iron supplements have a simultaneous-with-food exception for TIVICAY. St. John’s wort co-use is to be avoided because a dosing recommendation cannot be established.
How this applies: Restricted to the preparation and conditions described in this article.
The table includes both measured and predicted interactions. It does not quantify every mineral salt, product or botanical extract. Formulations and combination tablets require their own instructions.
Source 2: primary human pharmacokinetic trial
accp1.onlinelibrary.wiley.com · Source check Sep 10, 2026
Population: Twenty-four healthy adults enrolled in an open-label crossover trial; twenty-one completed the planned study.
Fasting simultaneous dosing reduced dolutegravir AUC by 39% with calcium and 54% with iron. A meal or giving dolutegravir two hours first counteracted the decrease.
How this applies: Restricted to the preparation and conditions described in this article.
Single-dose pharmacokinetics, not a long-term HIV outcome trial. Does not compare all calcium/iron salts or test the six-hours-after schedule directly. Industry-funded study; authors reported employment and stock options.
Source 3: government clinical guideline
clinicalinfo.hiv.gov · Source check Sep 10, 2026
Population: Adults and adolescents receiving antiretroviral therapy.
Supports product-specific spacing and the calcium/iron food exception; says not to coadminister St. John’s wort with dolutegravir.
How this applies: Restricted to the preparation and conditions described in this article.
Clinical guidance combines measured and predicted effects. The DTG supplement instructions specifically discuss calcium and iron; the zinc heading is not a zinc-only human experiment.
Research assessment: · Open full citations ↗
Review and change history
- Publication status
- Published research summary
- Clinical review
- Not yet recorded
| Date | Update |
|---|---|
| Article prepared | |
| Current prescribing instructions and original research checked. Article written with product-specific timing and explicit limits of the evidence. | |
| Research summary published |
Article revision: 7260eec6df780070
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.