Supplements and Bictegravir.
Bictegravir is an HIV integrase strand transfer inhibitor (INSTI): it blocks integration of viral DNA into the host genome. INSTIs bind polyvalent metal ions, which is why mineral supplements can reduce their absorption.
Bictegravir is an HIV integrase strand transfer inhibitor (INSTI). The class blocks the step where viral DNA is spliced into the host genome, and it is the backbone of UK first-line therapy. It carries one supplement interaction that is unusually concrete for this field. Integrase inhibitors work by binding the two magnesium ions in the enzyme's active site, and the same chemistry lets them bind polyvalent metal ions in the gut: calcium, magnesium, iron, zinc and aluminium. Ordinary mineral supplements can therefore cut absorption sharply, and the measured falls are large rather than marginal. Taken fasted at the same time, dolutegravir exposure drops by about 39 percent with a calcium supplement and 54 percent with iron, and bictegravir by about 33 percent and 63 percent. The remedy is timing rather than avoidance: these minerals are usually still appropriate, they just may not be taken together. The right gap differs between drugs, so it belongs with the HIV pharmacist rather than a general rule, and raltegravir is the exception where spacing alone may not be enough. Taking the dose with food removes the need for separation for some of these medicines but not all. Separately, the class is not metabolically uniform: raltegravir is not a CYP substrate at all, dolutegravir is mainly glucuronidated, while bictegravir and elvitegravir are genuine CYP3A substrates, so a CYP3A-active supplement is a real concern for some members and not others. St John's Wort is contraindicated with bictegravir and elvitegravir, needs a dose adjustment with dolutegravir, and is explicitly permitted with raltegravir, which is a sharper split than any other antiretroviral class. Because of that partner-drug exposure, the CYP3A-active supplements are excluded across the class rather than drug by drug: curcumin, quercetin, resveratrol, schisandra, berberine, boswellia and bergamot extract. Immune-active herbs (echinacea, andrographis, elderberry, cordyceps, astragalus) are excluded as a precaution on antiretroviral therapy regardless of CD4 count.
Below are the 7 documented pairs we have explicitly assessed against Bictegravir in the Distil database: 7 amber. The pairs cluster around 1 mechanism: Mineral chelation (absorption). Every call is cited to either a clinical reference (PMID) or the British National Formulary. Anything not on this list is either still to be assessed or beyond our database scope. The checker beneath surfaces assessments by supplement, and the missing-item form at the bottom of the page routes any uncatalogued supplement into our next curation pass.
Documented interactions
Last reviewed 31 August 2026. Each interaction below lists the evidence its assessment drew on: some rest on studies of the exact pair, others on mechanism evidence, where a citation may support one part of the reasoning rather than the exact combination. The evidence line on each entry says which.
Mineral chelation (absorption)
Amber Does Calcium interact with ?
Calcium can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Iron interact with ?
Iron can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Magnesium interact with ?
Magnesium can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does Magnesium Glycinate interact with ?
Magnesium glycinate can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does Magnesium L-Threonate interact with ?
Magnesium L-threonate can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Limited human data, based on case reports and a known mechanism.
Amber Does Zinc interact with ?
Zinc can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
Amber Does Zinc Bisglycinate interact with ?
Zinc bisglycinate can bind to Bictegravir in the gut, and taking them at the same time may sharply reduce how much of your HIV medicine you absorb, which in turn may reduce how well it works. Bictegravir is usually taken at least 2 hours BEFORE a magnesium or aluminium antacid, and taking it 2 hours after is not equivalent. Taking it with food at the same time is the other option. The gap that is right for you depends on which HIV medicine you take, so please check it with your HIV pharmacist before you start.
Evidence: Supported by human study data.
What this list does not say. Pairs not flagged here are not implicitly safe. They are either not yet in our database, or fall outside our inclusion scope (food-supplement interactions only; for drug-drug interactions, the BNF is authoritative). Use the checker below to surface any supplement, and submit a missing item if you take something we have not catalogued.
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How we grade severity, choose what's in scope, and what we exclude.
Every call on this page is reasoned. We publish the full rubric for severity tiers, the medication inclusion logic, the evidence grades we accept, and what we deliberately leave out. About three thousand words. Worth reading once if you use this tool more than occasionally.
Read the full methodologyA full supplement review, built around you, not a generic stack.
The free checker answers one interaction question at a time. A Distil report reviews the bigger picture: your goals, diet, medications, current supplements and any blood results you provide, then shows what appears worth keeping, changing, adding or leaving out.
- what your diet already covers, so you are not adding a capsule for something food is already handling
- which evidence-graded compounds are worth considering for your goals, and which were considered but left out
- what to keep, change or stop from what you already take, plus the order to introduce anything new
- how your medications and complete supplement stack fit together, with daily timing and a clear point for reassessment
The interaction check is one section of the full report. You also get the reasoning behind each recommendation and the evidence references used.
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