Drug & supplement interaction

Coffee Charcoal + Efavirenz

Efavirenz brand name: Sustiva.

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

Coffee Charcoal has a moderate interaction with Efavirenz. Coffee charcoal can reduce the absorption of orally administered drugs and should be separated from oral drug administration by at least two hours.

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

Coffee Charcoal and Efavirenz

Here is the interaction we found between these two, with the evidence behind it.

Moderate

ORAL DRUGS

Why this applies to Efavirenz

Efavirenz falls under ORAL DRUGS — the group Coffee Charcoal interacts with.

Coffee charcoal can reduce the absorption of orally administered drugs and should be separated from oral drug administration by at least two hours.
Severity Moderate Likelihood Probable Evidence D

Interaction 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..

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

Here's the thing to know about charcoal-type products like coffee charcoal: they work by binding things in your gut. The catch is they don't just grab onto fluid or irritants. They can also grab onto medications sitting in your stomach, including your efavirenz (Sustiva), before your body has a chance to absorb it.

If less efavirenz gets in, you may end up with lower levels in your blood. With an HIV medication, that's a real concern, because keeping steady drug levels is what keeps the virus suppressed and helps prevent resistance. This caution is based on how charcoal behaves in general (theoretical), not on a specific study with efavirenz. A simple fix is spacing them out, ideally at least two hours apart. Please check with your pharmacist or doctor before combining them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.

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

Coffee Charcoal Also Interacts With Other Medications

Coffee Charcoal has 2,021 moderate known drug interactions in our database — the Efavirenz one above is one of them. If you take anything else, check it against the full list below.

Moderate 2,021 No known interaction 809 (incl. Efavirenz)
Taking anything else?

Check Another of Your Medications Against Coffee Charcoal

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

Everything else you take

See Every Supplement That Interacts With Efavirenz

This page covers Coffee Charcoal only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Efavirenz page lists 159 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 · 117 moderate · 39 minor.

From our pharmacist’s overview on the Efavirenz page

“Efavirenz (Sustiva) is an HIV medicine, so an interaction that weakens it can cost more than a bad day; it can invite viral resistance. That makes this a list to treat with genuine care.”

Reviewed by 2 · Jul 18, 2026

Open the Efavirenz interaction page

How much people look this up

Where Coffee Charcoal and Efavirenz 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 Coffee Charcoal
Top half

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

29 days ago today
Medication Efavirenz
Top half

#1,330 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 Coffee Charcoal

What is Coffee Charcoal?

  • Diarrhea
  • Inflammatory bowel conditions
  • Irritable bowel syndrome (IBS)
  • Mild digestive upset
  • Wound and skin care (topical, traditional)

Coffee charcoal is made by roasting green coffee beans until they turn black, creating a charcoal-like material used traditionally for diarrhea and digestive complaints. Scientific evidence supporting its benefits is very limited, and it should not replace proven treatments. Talk with your pharmacist or doctor before using it, especially if you have a chronic gut condition.

Read the full Coffee Charcoal monograph & all interactions
Medication

About Efavirenz

What Is Efavirenz Used For?

Brand name: Sustiva

Efavirenz is used to treat HIV-1 (human immunodeficiency virus type 1) infection. It is always used together with other antiretroviral medicines — never on its own.

It is approved for adults and for children who are at least 3 months old and weigh at least 3.5 kg (about 7.7 lbs). Both the capsule and tablet forms are approved for this use.

See full Efavirenz drug information
Keep checking

Other Drugs & Coffee Charcoal

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

0Major
2,021Moderate
0Minor
808No known interaction
2,021 Moderate 808 No interaction
Moderate

2,021 interactions

Showing 60 of 2,021 moderate interactions — see all 2,021 on the Coffee Charcoal page.

No interaction 808 drugs checked — show the list

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

Showing the 60 most looked-up of 808 medications checked with no known interaction — see the full Coffee Charcoal list.

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

Can you take Coffee Charcoal with Efavirenz?
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.
How serious is the Coffee Charcoal and Efavirenz 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 Efavirenz and Coffee Charcoal?

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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.