Drug & supplement interaction

Cannabis + Rifampin

Rifampin brand names: Rifadin, Rimactane, Rifadin Injection, Rofactor.

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

Rifampin falls into 3 drug categories that Cannabis can interact with; the most serious is rated moderate. Theoretically, cannabis may increase the levels and adverse effects of CYP3A4 substrates.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Cannabis and Rifampin

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Cannabis interacts with whole categories of medication. Rifampin falls into 3 of those categories, so it can interact with Cannabis in 3 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) SUBSTRATES

1 of 3

Why this applies to Rifampin

Rifampin falls under CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES — the group Cannabis interacts with.

Theoretically, cannabis may increase the levels and adverse effects of CYP3A4 substrates.
In vitro research shows that cannabis can inhibit the activity of CYP3A4 enzymes, which might decrease the metabolism of CYP3A4 substrates. In vitro research also shows that cannabis extracts modestly inhibit the CYP3A4 metabolism of testosterone; extracts providing the specific cannabinoids CBD and cannabigerol (CBG) had stronger inhibitory effects than extracts containing THC and CBD.
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 idea on file: in lab dishes, cannabis can mildly block an enzyme called CYP3A4, and rifampin happens to be processed by that same enzyme. In theory, slowing that breakdown could let a bit more rifampin linger in your body, which might nudge up side effects like nausea, stomach upset, or stress on the liver.

That said, this is very weak evidence, only test-tube and animal data, not real people. And here's the twist worth knowing: rifampin is actually a powerful enzyme booster itself, so in real life it tends to overpower these effects and may even speed up how your body clears other things. I wouldn't lose sleep over this one, but since you're treating a serious infection like TB, please loop in your doctor or pharmacist before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Pellinen, P., Honkakoski, P., Stenback, F., Niemitz, M., Alhava, E., Pelkonen, O., Lang, M. A., and Pasanen, M. Cocaine N-demethylation and the metabolism-related hepatotoxicity can be prevented by cytochrome P450 3A inhibitors. Eur.J Pharmacol 1-3-1994;2 PubMed
  2. Treyer A, Reinhardt JK, Eigenmann DE, Oufir M, Hamburger M. Phytochemical comparison of medicinal cannabis extracts and study of their CYP-mediated interactions with coumarinic oral anticoagulants. Med Cannabis Cannabinoids. 2023;6(1):21-31. PubMed
Moderate

CYTOCHROME P450 3A4 (CYP3A4) INDUCERS

2 of 3

Rifampin also falls under CYTOCHROME P450 3A4 (CYP3A4) INDUCERS.

Theoretically, CYP3A4 inducers might reduce the levels and clinical effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP3A4 enzymes.
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: rifampin is one of the strongest "enzyme revvers" we have in medicine. It cranks up a liver enzyme called CYP3A4, which is one of the main systems that breaks down THC, the active compound in cannabis. So in this pairing, rifampin is the one doing the pushing, and cannabis is along for the ride.

What that likely means in real life is that your body could clear THC faster than usual, so you may notice less effect from your cannabis, whether you use it for relief or recreation. This isn't a dangerous combo, and the concern is mostly theoretical based on how the drugs work, not from strong studies. Keep taking your rifampin exactly as prescribed for your TB or infection, and chat with your pharmacist if your cannabis just doesn't seem to be working.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.
Moderate

CYTOCHROME P450 2C9 (CYP2C9) INDUCERS

3 of 3

Rifampin also falls under CYTOCHROME P450 2C9 (CYP2C9) INDUCERS.

Theoretically, drugs that are CYP2C9 inducers might decrease the effects of cannabis.
Delta-9-tetrahydrocannabinol (THC), an active constituent of cannabis, is a substrate of CYP2C9 enzymes.
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 this pairing: rifampin is one of the strongest 'enzyme revvers' we have. It speeds up liver enzymes, including CYP2C9, which is one of the enzymes that breaks down THC, the part of cannabis that gets you high. So when you take rifampin, your body may clear THC faster than usual. The practical result is that your cannabis might feel weaker or wear off sooner, and you may not get the relief or effect you're used to.

I want to be honest that this is a theoretical interaction, based on how these compounds are processed rather than solid studies in people, so the real-world impact is uncertain. It's also worth noting cannabis isn't changing how well your rifampin treats TB or meningitis. If you use cannabis regularly, just mention it to your doctor or pharmacist so they have the full picture.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Product information for Marinol. AbbVie. North Chicago, IL 60064. August 2017. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/018651s029lbl.pdf.

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

Cannabis Also Interacts With Other Medications

Cannabis has 2 major, 1,108 moderate, 25 minor known drug interactions in our database — the Rifampin one above is among them. If you take anything else, check it against the full list below.

Major 2 Moderate 1,108 Minor 25 No known interaction 1,695 (incl. Rifampin)
Taking anything else?

Check Another of Your Medications Against Cannabis

Covers the 2,830 medications we’ve checked against Cannabis. Pick one to open its full report.

From our Q&A

Questions About Cannabis or Rifampin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Cannabis or Rifampin, not necessarily both, but if one is close to what you were about to ask it will usually go further than a database entry can:

Not quite your question? Ask our pharmacists directly — it is free, there is no account required, and answers usually come back within 24 hours.

Everything else you take

See Every Supplement That Interacts With Rifampin

This page covers Cannabis only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Rifampin page lists 222 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), Apple (major), Asarabacca (major), Beer (major) and Grapefruit (major).

By severity: 9 major · 172 moderate · 41 minor.

From our pharmacist’s overview on the Rifampin page

“Rifampin (Rifadin) is the backbone of tuberculosis treatment, taken daily for months, which is plenty of time to pick up a juice habit or a probiotic without a second thought. With 222 supplement and food entries on file and 9 rated major, this list calls for real care, starting with the majors.”

Reviewed by 2 · Jul 18, 2026

Open the Rifampin interaction page

One more smart check

Taking Cannabis as Part of a Dietary Supplement Product? Check It for Interactions

We hold 21 real supplement products containing Cannabis, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Cannabis. Your product may carry other ingredients that interact with Rifampin too, on top of Cannabis — and those would not show on this page. Find your product and we’ll check every ingredient on its label:

How much people look this up

Where Cannabis and Rifampin 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 Cannabis
Top 25%

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

29 days ago today
Medication Rifampin
Steady interest

#1,452 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 Cannabis

What is Cannabis?

Cannabis
  • Chronic pain
  • Nausea and vomiting from chemotherapy
  • Muscle spasticity (e.g., multiple sclerosis)
  • Anxiety and stress
  • Sleep problems
  • Appetite stimulation

Cannabis contains many active compounds, mainly THC (which causes a 'high') and CBD (which does not). Some uses, such as chemotherapy-related nausea, certain seizure disorders, and muscle spasticity, have meaningful evidence, while many other popular uses are not well proven. It can cause real side effects and impairment, so talk to your doctor or pharmacist and follow your local laws before using it.

Read the full Cannabis monograph & all interactions
Medication

About Rifampin

What Is Rifampin Used For?

Brand names: Rifadin, Rimactane, Rifadin Injection, Rofactor

Rifampin treats all forms of tuberculosis (TB). It is almost always used in combination with other antibiotics — your doctor will build a multi-drug regimen tailored to your infection. Treatment usually runs for at least 6 months total.

Rifampin is also used to clear Neisseria meningitidis bacteria from the nose and throat in people who carry the germ without being sick themselves. It is not used to treat active meningococcal disease. The intravenous (IV) forms — Rifadin IV, Rifadin IV NOVAPLUS, and the injectable form of Rifampin — are specifically indicated when a patient cannot take the drug by mouth.

See full Rifampin drug information
Keep checking

Other Drugs & Cannabis

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

2Major
1,108Moderate
25Minor
1,694No known interaction
2 Major 1,108 Moderate 25 Minor 1,694 No interaction
Major

2 interactions

Moderate

1,108 interactions

Showing 60 of 1,108 moderate interactions — see all 1,108 on the Cannabis page.

Minor

25 interactions

No interaction 1,694 drugs checked — show the list

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

Showing the 60 most looked-up of 1,694 medications checked with no known interaction — see the full Cannabis list.

See the full Cannabis interactions page
See every supplement checked against Rifampin, 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
Cannabis monograph › Uses, safety, and every drug interaction in one place Rifampin supplement interactions › Every supplement checked against Rifampin, ranked by severity Rifampin 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 Cannabis and Rifampin Together: Common Questions

Can you take Cannabis with Rifampin?
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 3 interactions listed for Cannabis and Rifampin?
Rifampin belongs to more than one drug category, and Cannabis 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 Cannabis and Rifampin 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

Still Have a Question About Rifampin and Cannabis?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.