Supplements and Cobicistat.
Cobicistat, sold under the brand name Tybost, is a pharmacokinetic booster: it has no antiviral activity of its own and is given to raise the exposure of another antiretroviral by inhibiting CYP3A4.
Cobicistat is a pharmacokinetic booster. It has no antiviral activity of its own. It is given because it is a strong inhibitor of CYP3A4, which slows the clearance of the antiretroviral it is paired with and holds that drug at a useful level on a once-daily dose. That makes the supplement picture unusual, because the interaction runs in both directions. A supplement that induces CYP3A4, St John's Wort above all, lowers the booster and the boosted drug together, which risks loss of virological control. A supplement that inhibits CYP3A4, such as curcumin, quercetin, resveratrol, schisandra, berberine, boswellia or bergamot, stacks on top of an inhibition that is already deliberate and near-maximal. And because the booster suppresses CYP3A4 generally, supplements that are themselves CYP3A4 substrates can reach higher levels than they otherwise would, which is the reverse of the usual concern. St John's Wort is contraindicated. Immune-active herbs (echinacea, andrographis, elderberry, cordyceps, astragalus) are excluded as a precaution on antiretroviral therapy regardless of CD4 count. Any supplement decision belongs with the HIV team.
We have not yet completed an explicit assessment of supplement interactions with Cobicistat in the Distil database. That is different from saying nothing exists. We surface this distinction deliberately: the Distil checker tells you when we have explicitly assessed a pair and when we have not, because both are useful information. If you take Cobicistat alongside a supplement, the checker below will surface anything already in our database, and the missing-item form at the bottom of the page routes uncatalogued pairs into our next curation pass.
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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Something missing?
If a supplement or medication you take isn't in our autocomplete, tell us. We go through what people flag every week and add what's missing.