Drug & supplement interaction

Coleus + Erythromycin

Erythromycin brand names: Erythro S, PCE, E-Mycin, Erythro-ES, EryPed Chewable, and others.

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

Coleus has a moderate interaction with Erythromycin. Theoretically, taking coleus might decrease serum levels of drugs metabolized by CYP3A4.

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

Coleus and Erythromycin

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Erythromycin

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

Theoretically, taking coleus might decrease serum levels of drugs metabolized by CYP3A4.
In vitro research shows that coleus can activate the nuclear receptor, pregnane X receptor (PXR), which results in increased expression of CYP3A4. Although the clinical significance of this is not known, use caution when considering concomitant use of coleus and other drugs affected by these 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 with Coleus and erythromycin. Your body clears erythromycin partly through a liver enzyme called CYP3A4. In lab (test tube) studies, Coleus appears to flip on a switch that makes your body produce more of this enzyme. More enzyme could mean erythromycin gets broken down a bit faster, leaving less of it to fight your infection.

The worry would be a weaker antibiotic that doesn't fully clear the infection you're treating. That said, this is theoretical and based only on lab research, not on real people, so I wouldn't lose sleep over it. Still, since this is an active infection where you need the full benefit, it's worth a quick chat with your pharmacist or doctor before pairing them.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Ding, X. and Staudinger, J. L. Induction of drug metabolism by forskolin: the role of the pregnane X receptor and the protein kinase a signal transduction pathway. J Pharmacol Exp Ther 2005;312(2):849-856. PubMed
  2. Staudinger, J. L., Ding, X., and Lichti, K. Pregnane X receptor and natural products: beyond drug-drug interactions. Expert.Opin Drug Metab Toxicol 2006;2(6):847-857. 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

Coleus Also Interacts With Other Medications

Coleus has 29 major, 885 moderate known drug interactions in our database — the Erythromycin one above is one of them. If you take anything else, check it against the full list below.

Major 29 Moderate 885 No known interaction 1,916 (incl. Erythromycin)
Taking anything else?

Check Another of Your Medications Against Coleus

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

From our Q&A

Questions About Coleus or Erythromycin

These are real questions from readers, answered by the pharmacists at HelloPharmacist — written by a person, not generated from a database. Each one covers Coleus or Erythromycin, 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 Erythromycin

This page covers Coleus only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Erythromycin page lists 204 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), Arsenic (major), Beer (major) and Cesium (major).

By severity: 11 major · 153 moderate · 40 minor.

From our pharmacist’s overview on the Erythromycin page

“Erythromycin calls for more supplement caution than most antibiotics, and the reason is one liver enzyme, CYP3A4. Erythromycin both blocks that enzyme and is broken down by it, so grapefruit can push erythromycin levels up while St.”

Reviewed by 2 · Jul 18, 2026

Open the Erythromycin interaction page

One more smart check

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

We hold 803 real supplement products containing Coleus, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Coleus. Your product may carry other ingredients that interact with Erythromycin too, on top of Coleus — 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 Coleus and Erythromycin 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 Coleus
Top 25%

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

29 days ago today
Medication Erythromycin
Top 25%

#371 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 Coleus

What is Coleus?

Coleus
  • Weight management
  • Asthma and breathing
  • High blood pressure
  • Heart conditions
  • Glaucoma (eye pressure)
  • Exercise and body composition

Coleus is a plant from the mint family whose root contains a compound called forskolin, often marketed for weight loss, asthma, and heart health. While early lab and small human studies are interesting, solid proof that Coleus supplements help any of these conditions is limited. Talk to your pharmacist or doctor before using it, especially if you have heart problems or low blood pressure.

Read the full Coleus monograph & all interactions
Medication

About Erythromycin

What Is Erythromycin Used For?

Brand names: Erythro S, PCE, E-Mycin, Erythro-ES, EryPed Chewable, Eryc, Ery-Tab, Rythro Enca, Erythro E-C, Erythro Base, Ilosone, Ilotycin

Erythromycin treats bacterial infections caused by susceptible organisms. Oral and intravenous forms are used for upper and lower respiratory tract infections, skin and soft-tissue infections, pertussis (whooping cough), Legionnaires' disease, sexually transmitted infections (gonorrhea, syphilis, chlamydia), listeriosis, and other conditions. Erythrocin Lactobionate IV and erythromycin lactobionate injection are specifically for patients who cannot take oral medication or who need rapid, high blood levels due to severe infection — IV therapy should be switched to oral as soon as appropriate.

Erythromycin topical solution 2% and Ery 2% Pads (swabs) are indicated only for the topical treatment of acne vulgaris (acne) and are applied directly to the skin — they are not used for internal infections.

See full Erythromycin drug information
Keep checking

Other Drugs & Coleus

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

29Major
885Moderate
0Minor
1,915No known interaction
29 Major 885 Moderate 1,915 No interaction
Major

29 interactions

Moderate

885 interactions

Showing 60 of 885 moderate interactions — see all 885 on the Coleus page.

No interaction 1,915 drugs checked — show the list

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

Showing the 60 most looked-up of 1,915 medications checked with no known interaction — see the full Coleus list.

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

Can you take Coleus with Erythromycin?
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 Coleus and Erythromycin 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 Erythromycin and Coleus?

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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.