Drug & supplement interaction

Cannabinol (cbn) + Atazanavir, Cobicistat

Atazanavir, Cobicistat brand name: Evotaz.

Moderate Interaction
Medically reviewed by · Updated September 2026
The bottom line Moderate

Atazanavir, Cobicistat falls into 2 drug categories that Cannabinol (cbn) can interact with; the most serious is rated moderate. Theoretically, CYP3A4 inhibitors might increase the levels and clinical effects of cannabinol.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions2
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Cannabinol (cbn) and Atazanavir, Cobicistat

These two interact in 2 distinct ways. Each one is explained separately below.

Why Are There 2 Interactions?

Cannabinol (cbn) interacts with whole categories of medication. Atazanavir, Cobicistat falls into 2 of those categories, so it can interact with Cannabinol (cbn) in 2 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS

1 of 2

Why this applies to Atazanavir, Cobicistat

Atazanavir, Cobicistat falls under CYTOCHROME P450 3A4 (CYP3A4) INHIBITORS — the group Cannabinol (cbn) interacts with.

Theoretically, CYP3A4 inhibitors might increase the levels and clinical effects of cannabinol.
In vitro research shows that CYP3A4 enzymes are involved in the 8-hydroxylation of cannabinol. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the key thing to know: in your Evotaz combo, the cobicistat piece is a deliberate booster that blocks the CYP3A4 enzyme. That's actually how it works, it slows the breakdown of atazanavir so HIV gets treated more effectively. The catch is that this same blocking action can also slow how your body clears CBN, since lab studies show CYP3A4 helps process it.

So the concern runs one direction: your CBN levels could climb higher than expected, possibly meaning more drowsiness, grogginess, or next-day sluggishness. To be clear, this is theoretical and only seen in test-tube research, never reported in real people. Still, because your HIV regimen is so important to keep steady, please check with your pharmacist or doctor before adding any cannabis product.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Watanabe K, Yamaori S, Funahashi T, Kimura T, Yamamoto I. Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes. Life Sci. 2007;80(15):1415-9. PubMed
Moderate

CYTOCHROME P450 2C9 (CYP2C9) INHIBITORS

2 of 2

Atazanavir, Cobicistat also falls under CYTOCHROME P450 2C9 (CYP2C9) INHIBITORS.

Theoretically, CYP2C9 inhibitors might increase the levels and clinical effects of cannabinol.
In vitro research shows that CYP2C9 enzymes are involved in the 11-hydroxylation of cannabinol. So far, this interaction has not been reported in humans.
Severity Moderate Likelihood Possible Evidence D

Interaction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.

Dr. Brian Staiger, PharmD, BCPS
Dr. Brian Staiger explains PharmD, Clinical Pharmacist

Here's the gist for Evotaz (atazanavir with cobicistat) and CBN: both atazanavir and the booster cobicistat block a liver enzyme called CYP2C9. Lab studies suggest CBN is partly cleared by that same enzyme. So in theory, taking Evotaz could slow down how your body breaks CBN down, letting it build up and hit you harder than expected. That might mean more drowsiness, dizziness, or grogginess from the CBN, not from your HIV medicine.

Importantly, this is only test-tube evidence and hasn't actually been seen in people. Your Evotaz keeps working the same either way. Still, because cannabis products vary a lot in quality and strength, please run any CBN product by your pharmacist or HIV provider before trying it.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Watanabe K, Yamaori S, Funahashi T, Kimura T, Yamamoto I. Cytochrome P450 enzymes involved in the metabolism of tetrahydrocannabinols and cannabinol by human hepatic microsomes. Life Sci. 2007;80(15):1415-9. PubMed

What These Ratings Mean

Every interaction above is graded three ways — here’s the key to each label.

Severity how clinically significant the interaction is
Major

Clinically significant. Avoid the combination, or use only under close professional supervision.

Moderate

Usually worth avoiding or managing — may need monitoring, a dose change, or timing apart.

Minor

Generally not serious. Be aware of it and mention it to your pharmacist.

Likelihood how strong the evidence is that the interaction actually happens in people
  • LikelyWell-controlled human studies have demonstrated the likely existence of this interaction.
  • ProbableInteraction has not been documented in well-controlled studies, however, the interaction has been demonstrated in some small human studies or in controlled animal studies in conjunction with multiple case reports.
  • PossibleInteraction has been documented in animal or in lab research, or the interaction has been documented in humans but is limited to case reports or conflicting clinical research exists.
  • UnlikelyInteraction has been demonstrated in animal or in lab research but has been shown not to occur in humans.
Evidence the quality of the studies behind the rating (graded A–D)
  • AHigh-quality meta-analysis (quantitative systematic review).
  • BCase-control study.
  • CConsensus.
  • DAnecdotal evidence.

These ratings are for information only. Never start, stop, or otherwise change your therapy before speaking with your provider.

Keep it in perspective

Cannabinol (cbn) Also Interacts With Other Medications

Cannabinol (cbn) has 388 moderate known drug interactions in our database — the Atazanavir, Cobicistat one above is among them. If you take anything else, check it against the full list below.

Moderate 388 No known interaction 2,442 (incl. Atazanavir, Cobicistat)
Taking anything else?

Check Another of Your Medications Against Cannabinol (cbn)

Covers the 2,830 medications we’ve checked against Cannabinol (cbn). Pick one to open its full report.

Everything else you take

See Every Supplement That Interacts With Atazanavir, Cobicistat

This page covers Cannabinol (cbn) only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Atazanavir, Cobicistat page lists 152 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Grapefruit (major), St. John's Wort (major), Acacia Rigidula (moderate) and Adrafinil (moderate).

By severity: 3 major · 107 moderate · 42 minor.

From our pharmacist’s overview on the Atazanavir, Cobicistat page

“Evotaz (atazanavir with cobicistat) treats HIV, and its effectiveness depends on steady blood levels, so I read this list of 152 supplements and herbs carefully rather than casually. Only three carry a major rating, but those three deserve your attention first: St.”

Reviewed by 2 · Jul 18, 2026

Open the Atazanavir, Cobicistat interaction page

How much people look this up

Where Cannabinol (cbn) and Atazanavir, Cobicistat Sit Against Everything Else

Out of every supplement and medication people look up on HelloPharmacist, here is where these two land this week — and which way each has been moving.

Supplement Cannabinol (cbn)
Top half

#468 of 1,452 supplements looked up here in the last 7 days

29 days ago today
Medication Atazanavir, Cobicistat
Top 25%

#373 of 2,830 medications looked up here in the last 7 days

29 days ago today

Position among everything looked up on this site, not a measure of how commonly either one is used or how important it is. A supplement can climb this list because of a news story. It counts every request to the page, automated ones included, and nothing here identifies anyone.

Supplement

About Cannabinol (cbn)

What is Cannabinol (cbn)?

  • Sleep support
  • Relaxation
  • Pain or discomfort
  • Appetite-related concerns

Cannabinol (CBN) is a minor cannabinoid found in the cannabis plant, often marketed as a 'sleep' aid, but solid human research is very limited. Because it comes from cannabis and product quality varies widely, talk with your pharmacist or doctor before trying it, and avoid it during pregnancy and breastfeeding.

Read the full Cannabinol (cbn) monograph & all interactions
Medication

About Atazanavir and Cobicistat

What Is Atazanavir and Cobicistat Used For?

Brand name: Evotaz

Evotaz (atazanavir/cobicistat) is used to treat HIV-1 infection. It must always be taken together with other antiretroviral medicines — it is not a complete regimen on its own. It is approved for adults and for pediatric patients who weigh at least 35 kg.

In patients who have been on HIV treatment before (treatment-experienced), how well Evotaz works depends on how much resistance to protease inhibitors the virus has already developed. Your prescriber will review this before starting you on Evotaz.

See full Atazanavir and Cobicistat drug information
Keep checking

Other Drugs & Cannabinol (cbn)

Browse every other medication we’ve checked against Cannabinol (cbn) — both the ones with a known interaction and the ones without. Select any drug for the full detail.

0Major
388Moderate
0Minor
2,441No known interaction
388 Moderate 2,441 No interaction
Moderate

388 interactions

Showing 60 of 388 moderate interactions — see all 388 on the Cannabinol (cbn) page.

No interaction 2,441 drugs checked — show the list

We also checked Cannabinol (cbn) against these medications and found no known interaction in our sources. Open any page to confirm.

Showing the 60 most looked-up of 2,441 medications checked with no known interaction — see the full Cannabinol (cbn) list.

See the full Cannabinol (cbn) interactions page
See every supplement checked against Atazanavir, Cobicistat, ranked by severity
Sources

Sources & How We Checked

Interaction details are evidence-graded and sourced from the Natural Medicines database. The medication overview comes from MedlinePlus.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

Keep exploring
Cannabinol (cbn) monograph › Uses, safety, and every drug interaction in one place Atazanavir, Cobicistat supplement interactions › Every supplement checked against Atazanavir, Cobicistat, ranked by severity Atazanavir and Cobicistat drug information › The full plain-English guide to this medication Supplement interaction checker › Check any supplement or product against your medications Browse medications A–Z › Every drug we've checked against herbs & supplements Ask a pharmacist › Free, personal answer from our licensed team
Pharmacist Counseling Corner

Taking Cannabinol (cbn) and Atazanavir, Cobicistat Together: Common Questions

Can you take Cannabinol (cbn) with Atazanavir, Cobicistat?
There is a moderate interaction, so it may be acceptable with monitoring or timing changes — but check with your pharmacist first. Read the full details on this page and confirm with your pharmacist before combining them.
Why are there 2 interactions listed for Cannabinol (cbn) and Atazanavir, Cobicistat?
Atazanavir, Cobicistat belongs to more than one drug category, and Cannabinol (cbn) interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Cannabinol (cbn) and Atazanavir, Cobicistat interaction?
We rate it Moderate. This combination may require monitoring, a dose adjustment, or separating the times you take each one. Consult your pharmacist before using them together.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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This information is for education only and is not a substitute for professional medical advice. Always check with your pharmacist or doctor before starting, stopping, or combining supplements and medications.