Drug & supplement interaction

Coffee Charcoal + Ganciclovir

Ganciclovir brand names: Cytovene, Cytovene Injection.

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

Coffee Charcoal has a moderate interaction with Ganciclovir. 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 Ganciclovir

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

Moderate

ORAL DRUGS

Why this applies to Ganciclovir

Ganciclovir 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 concern with taking coffee charcoal alongside your oral ganciclovir (Cytovene). Like other charcoal-type products, coffee charcoal has a porous surface that can grab onto medications sitting in your gut. If it binds up your ganciclovir before your body can absorb it, less of the drug gets into your bloodstream. That could mean weaker protection against your CMV infection, which matters a lot when the goal is preventing something like vision-threatening eye disease.

The good news is this is a theoretical concern based on how charcoal behaves, not strong human studies. A simple fix is spacing them out by at least two hours. Please run this by your pharmacist or doctor first, since keeping your antiviral working well is the priority here.

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 Ganciclovir 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. Ganciclovir)
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 Ganciclovir

This page covers Coffee Charcoal only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Ganciclovir page lists 17 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), European Mandrake (moderate), Glucomannan (moderate), Guar Gum (moderate) and Gum Arabic (moderate).

By severity: 1 major · 7 moderate · 9 minor.

From our pharmacist’s overview on the Ganciclovir page

“Everything on this list threatens ganciclovir (Cytovene) the same way, by getting between the pill and your bloodstream. Ganciclovir fights cytomegalovirus in people whose immune systems are weakened, so a dose that only partly absorbs can let the virus regain ground and grow resistant.”

Reviewed by 2 · Jul 18, 2026

Open the Ganciclovir interaction page

How much people look this up

Where Coffee Charcoal and Ganciclovir 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

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

29 days ago today
Medication Ganciclovir
Top half

#1,282 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 Ganciclovir

What Is Ganciclovir Used For?

Brand names: Cytovene, Cytovene Injection

Ganciclovir injection (sold as Cytovene and generic products) is used in adults to treat CMV retinitis — a serious eye infection caused by cytomegalovirus — in people with weakened immune systems, including those with AIDS. It is also used to prevent CMV disease in adult transplant recipients who are at risk.

Zirgan (ganciclovir ophthalmic gel) is used to treat acute herpetic keratitis — a painful corneal ulcer caused by the herpes simplex virus — in adults and children aged 2 years and older.

See full Ganciclovir 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 Ganciclovir, 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 Ganciclovir supplement interactions › Every supplement checked against Ganciclovir, ranked by severity Ganciclovir 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 Ganciclovir Together: Common Questions

Can you take Coffee Charcoal with Ganciclovir?
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 Ganciclovir 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 Ganciclovir 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.