Drug & supplement interaction

Phellodendron + Dexamethasone

Dexamethasone brand names: Decadron, Hexadrol, Dexone, Ozurdex, Dexycu, and others.

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

Phellodendron has a moderate interaction with Dexamethasone. Theoretically, phellodendron might increase 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

Phellodendron and Dexamethasone

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

Moderate

CYTOCHROME P450 3A4 (CYP3A4) SUBSTRATES

Why this applies to Dexamethasone

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

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.
Phellodendron contains berberine. In vitro research and preliminary clinical research show that berberine moderately inhibits CYP3A4. Theoretically, phellodendron might also inhibit CYP3A4.
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

Your body relies on a liver enzyme called CYP3A4 to help clear dexamethasone. Phellodendron contains berberine, which lab and early human studies suggest can slow that same enzyme down a bit. If that happens, dexamethasone could hang around longer and build up, meaning its effects (and side effects) may feel a little stronger than expected.

In real life that might look like more fluid retention, mood or sleep changes, higher blood sugar, or stomach upset. I want to be honest though: this is a theoretical concern based on how berberine behaves in the lab, not a proven problem in people. It's worth a quick chat with your pharmacist or doctor before combining them, but please don't stop either one on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Wu X, Li Q, Xin H, Yu A, Zhong M. Effects of berberine on the blood concentration of cyclosporin A in renal transplanted recipients: clinical and pharmacokinetic study. Eur J Clin Pharmacol 2005;61:567-72. PubMed
  2. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  3. Guo, Y., Chen, Y., Tan, Z. R., Klaassen, C. D., and Zhou, H. H. Repeated administration of berberine inhibits cytochromes P450 in humans. Eur J Clin Pharmacol 2012;68(2):213-217. PubMed
  4. Hermann, R. and von, Richter O. Clinical evidence of herbal drugs as perpetrators of pharmacokinetic drug interactions. Planta Med 2012;78(13):1458-1477. 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

Phellodendron Also Interacts With Other Medications

Phellodendron has 1,161 moderate known drug interactions in our database — the Dexamethasone one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,161 No known interaction 1,669 (incl. Dexamethasone)
Taking anything else?

Check Another of Your Medications Against Phellodendron

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

From our Q&A

Questions About Phellodendron or Dexamethasone

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

This page covers Phellodendron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Dexamethasone page lists 221 supplements it has a documented interaction with, worst first, each one explained.

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

By severity: 4 major · 182 moderate · 35 minor.

From our pharmacist’s overview on the Dexamethasone page

“People take dexamethasone for serious reasons, a chemotherapy course, an autoimmune flare, brain swelling, so I want anyone on it to give its 221 supplement interactions genuine attention, starting with the four rated major. Grapefruit and St.”

Reviewed by 2 · Jul 18, 2026

Open the Dexamethasone interaction page

One more smart check

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

We hold 393 real supplement products containing Phellodendron, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Phellodendron. Your product may carry other ingredients that interact with Dexamethasone too, on top of Phellodendron — 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 Phellodendron and Dexamethasone 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 Phellodendron
Top 25%

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

29 days ago today
Medication Dexamethasone
Top 25%

#514 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 Phellodendron

What is Phellodendron?

Phellodendron
  • Digestive complaints and diarrhea
  • Inflammation and joint discomfort
  • Stress and weight management (in combination products)
  • Skin conditions (topical, traditional)
  • Antimicrobial support

Phellodendron is a traditional Chinese medicine bark (Huang Bai) that contains berberine and other plant compounds with antimicrobial and anti-inflammatory activity in lab studies. Human evidence for most uses is limited, and it is often sold in combination with other herbs, making its individual effects hard to judge. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Phellodendron monograph & all interactions
Medication

About Dexamethasone

What Is Dexamethasone Used For?

Brand names: Decadron, Hexadrol, Dexone, Ozurdex, Dexycu, Hemady, Dextenza

Dexamethasone is mainly used to calm inflammation and overactive immune responses. Depending on the product, it treats allergic conditions, skin diseases, adrenal and other hormone disorders, and certain bowel diseases.

Some uses belong only to specific products. Hemady tablets are used with other anti-myeloma medicines for adults with multiple myeloma. Dextenza (an eye insert) treats eye inflammation and pain after eye surgery and eye itching from allergic conjunctivitis. Ozurdex (an eye implant) treats macular edema after retinal vein occlusion, non-infectious uveitis of the back of the eye, and diabetic macular edema. Maxidex and dexamethasone sodium phosphate eye drops treat steroid-responsive inflammation of the front of the eye.

See full Dexamethasone drug information
Keep checking

Other Drugs & Phellodendron

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

0Major
1,161Moderate
0Minor
1,668No known interaction
1,161 Moderate 1,668 No interaction
Moderate

1,161 interactions

Showing 60 of 1,161 moderate interactions — see all 1,161 on the Phellodendron page.

No interaction 1,668 drugs checked — show the list

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

Showing the 60 most looked-up of 1,668 medications checked with no known interaction — see the full Phellodendron list.

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

Can you take Phellodendron with Dexamethasone?
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 Phellodendron and Dexamethasone 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 Dexamethasone and Phellodendron?

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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.