Herb & supplement monograph

Phellodendron Drug Interactions, Uses, Effectiveness, Safety & More

Medically reviewed by ·Updated July 2026
What is this page for?

First and foremost: how Phellodendron interacts with medications. The heart of this page is the interaction list — every drug Phellodendron is known to interact with, and how serious each one is.

But these pages have grown well beyond that into a full monograph — what Phellodendron is, what people use it for and how strong the evidence is, its safety and side effects, and answers to the questions we’re asked most — written and reviewed by the clinical staff at HelloPharmacist. It’s educational information from our licensed clinical databases, not medical advice, and we don’t sell or endorse products. Our editorial policy

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Phellodendron Drug Interactions: The Bottom Line

From the HelloPharmacist Editorial Team · Updated July 2026

Based on the available evidence, the overall risk of a clinically significant Phellodendron drug interaction appears low for most people, even though the list of possible interactions is long. None of the listed interactions are rated major, and nearly all are theoretical concerns tied to berberine, a compound in phellodendron bark.

Interactions deserving the most attention

The best-supported concerns involve transplant medicines: in one reported patient, berberine sharply raised blood levels of tacrolimus, and early human research suggests it may also slow the clearance of cyclosporine. Because berberine has lowered blood sugar in human studies, phellodendron could add to the effect of diabetes medications, including metformin. Additive effects on blood pressure, bleeding risk, and sedation are also possible, but these are based mostly on lab or animal findings.

What the rest of the list means

Most of this long list comes from one shared idea: berberine may slow enzymes the body uses to clear many common medications, which could raise their levels. Almost all of these interactions are predicted from lab, animal, or small preliminary studies rather than proven in people, so appearing on the list does not mean a combination will actually cause harm.

Check your medications against Phellodendron

Based on HelloPharmacist’s Phellodendron interaction data and reviewed under our editorial standards.

Interaction report

Drugs that interact with Phellodendron

1160 medications have a known interaction with Phellodendron, graded by severity. Select any drug for the full evidence-based detail.

2,830 drugs
Ado-trastuzumab EmtansineKadcyla
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Ado-trastuzumab Emtansine interaction Ado-trastuzumab Emtansine drug page: uses, dosage & side effects
AbciximabReoPro
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.

Read the full Phellodendron + Abciximab interaction
AbemaciclibVerzenio
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Abemaciclib interaction Abemaciclib drug page: uses, dosage & side effects
Abiraterone
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Abiraterone interaction Abiraterone drug page: uses, dosage & side effects
Abiraterone AcetateYonsa, Zytiga
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Abiraterone Acetate interaction Abiraterone Acetate drug page: uses, dosage & side effects
AbrocitinibCibinqo
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.

Read the full Phellodendron + Abrocitinib interaction Abrocitinib drug page: uses, dosage & side effects
AcalabrutinibCalquence
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acalabrutinib interaction Acalabrutinib drug page: uses, dosage & side effects
AcarboseGlucobay, Prandase, Precose
Moderate Antidiabetes Drugs

Theoretically, phellodendron may increase the risk of hypoglycemia when taken with antidiabetes drugs.

Read the full Phellodendron + Acarbose interaction Acarbose drug page: uses, dosage & side effects
AcebutololRhotral, Sectral
Moderate Antihypertensive Drugs

Theoretically, phellodendron might have additive effects with antihypertensive drugs.

Read the full Phellodendron + Acebutolol interaction Acebutolol drug page: uses, dosage & side effects
AcenocoumarolSintrom
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.

Read the full Phellodendron + Acenocoumarol interaction
AcepromazineAtravet
Moderate Cns Depressants

Theoretically, phellodendron might increase the sedative effects of CNS depressants.

Read the full Phellodendron + Acepromazine interaction
Acetaminophen, AspirinGemnisyn
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.

Read the full Phellodendron + Acetaminophen, Aspirin interaction
Acetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
Moderate Anticoagulant/antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.

Read the full Phellodendron + Acetaminophen, Aspirin, Caffeine interaction
Acetaminophen, Butalbital, CaffeineEsgic, Esgic Plus, Fiogesic, Fioricet, Repan, Tecnal +1 more
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Butalbital, Caffeine interaction Acetaminophen, Butalbital, Caffeine drug page: uses, dosage & side effects
Acetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Butalbital, Caffeine, Codeine interaction
Acetaminophen, Butalbital, CodeineBancap w/ Codeine
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Butalbital, Codeine interaction
Acetaminophen, Butalbital, Codeine PhosphatePhrenilin #3
Moderate Cns Depressants

Theoretically, phellodendron might increase the sedative effects of CNS depressants.

Read the full Phellodendron + Acetaminophen, Butalbital, Codeine Phosphate interaction
Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interaction
Acetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more
Moderate Cns Depressants

Theoretically, phellodendron might increase the sedative effects of CNS depressants.

Read the full Phellodendron + Acetaminophen, Caffeine, Codeine interaction
Acetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Caffeine, Codeine, Salicylamide interaction
Acetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Caffeine, Dihydrocodeine interaction
Acetaminophen, Caffeine, IsomethepteneMigralam
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Caffeine, Isometheptene interaction
Acetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Caffeine, Pyrilamine interaction
Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interaction
Acetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interaction
Acetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Dextromethorphan interaction
Acetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu
Moderate Dextromethorphan (robitussin Dm, Others)

Theoretically, phellodendron may increase serum levels of dextromethorphan.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interaction
Acetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief
Moderate Cytochrome P450 2d6 (cyp2d6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interaction
Acetaminophen, Chlorpheniramine, Dextromethorphan, PseudoephedrineChildren's Tylenol Cold Plus Cough, Tylenol Cold Ex Strength
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Dextromethorphan, Pseudoephedrine interaction
Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, SalicylamideRhinogesic GG
Moderate Cytochrome P450 3a4 (cyp3a4) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP3A4.

Read the full Phellodendron + Acetaminophen, Chlorpheniramine, Guaifenesin, Phenylephrine, Salicylamide interaction
Read The List Like a Pharmacist

What Severity, Likelihood & Evidence Mean

Severity — How Serious It Can Be

  • Major. Clinically significant; generally best avoided, or used only under direct professional supervision.
  • Moderate. May need monitoring, a dose adjustment, or separating the times you take each one.
  • Minor. Generally not clinically significant, but still worth noting and mentioning to your pharmacist.
  • No known interaction. Checked against our sources with nothing documented — not the same as proven safety.

Likelihood — How Well It’s Documented

  • Likely. Well-controlled human studies have demonstrated the likely existence of this interaction
  • Probable. 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.
  • Possible. 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
  • Unlikely. Interaction has been demonstrated in animal or in lab research but has been shown not to occur in humans.

Where This Data Comes From

  • Interaction records are evidence-graded and sourced from the Natural Medicines database (TRC Healthcare), the same reference used by pharmacists and hospitals.
  • Each drug listed above links to the full report for that exact Phellodendron combination — clinical detail, likelihood, evidence level, and citations.
  • Content is reviewed by licensed HelloPharmacist pharmacists — see our data sources and editorial standards.
The big picture

The kinds of drugs Phellodendron affects

Every type of medication (drug category) Phellodendron is known to interact with. Open any category for the detail — or search your exact drug in the checker above.

All 14 drug categories Phellodendron interacts with
Anticoagulant/antiplatelet DrugsAntidiabetes DrugsAntihypertensive DrugsCns DepressantsCyclosporine (neoral, Sandimmune)Cytochrome P450 2c9 (cyp2c9) SubstratesCytochrome P450 2d6 (cyp2d6) SubstratesCytochrome P450 3a4 (cyp3a4) SubstratesDextromethorphan (robitussin Dm, Others)Losartan (cozaar)Metformin (glucophage)Midazolam (versed)Pentobarbital (nembutal)Tacrolimus (prograf)
Anticoagulant/Antiplatelet Drugs

Theoretically, phellodendron might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.
Phellodendron contains berberine. In vitro and in vivo research suggest that berberine can inhibit platelet aggregation. Theoretically, phellodendron might also inhibit platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, phellodendron may increase the risk of hypoglycemia when taken with antidiabetes drugs.
Phellodendron contains berberine. Clinical research shows that berberine may lower blood glucose levels. Theoretically, phellodendron might also lower blood glucose levels.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, phellodendron might have additive effects with antihypertensive drugs.
Phellodendron contains berberine. Animal research suggests that berberine can have hypotensive effects. Also, a clinical study suggests that taking berberine in combination with amlodipine can lower systolic and diastolic blood pressure when compared with amlodipine alone. Theoretically, phellodendron might also reduce blood pressure.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, phellodendron might increase the sedative effects of CNS depressants.
Phellodendron contains berberine. Animal research suggests that berberine may have sedative effects. Theoretically, phellodendron might also have CNS depressants effects.

Likelihood Possible Evidence D
Cyclosporine (Neoral, Sandimmune)

Theoretically, phellodendron might increase blood levels of cyclosporine.
Phellodendron contains berberine. Preliminary clinical research shows that berberine can reduce metabolism of cyclosporine and increase serum levels, likely through inhibition of cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporine. Theoretically, phellodendron might also reduce the metabolism of cyclosporine.

Likelihood Possible Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2C9.
Phellodendron contains berberine. Preliminary clinical research shows that berberine can inhibit CYP2C9. Theoretically, phellodendron might also inhibit CYP2C9.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, phellodendron might increase serum levels of drugs metabolized by CYP2D6.
Phellodendron contains berberine. In vitro research and preliminary clinical evidence show that berberine can inhibit CYP2D6. Theoretically, phellodendron might also inhibit CYP2D6.

Likelihood Possible Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

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.

Likelihood Possible Evidence D
Dextromethorphan (Robitussin Dm, Others)

Theoretically, phellodendron may increase serum levels of dextromethorphan.
Phellodendron contains berberine. Preliminary clinical research shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan. Theoretically, phellodendron may also inhibit the metabolism of dextromethorphan.

Likelihood Possible Evidence D
Losartan (Cozaar)

Theoretically, phellodendron might reduce the therapeutic effects of losartan by decreasing its conversion to its active form.
Phellodendron contains berberine. Preliminary clinical research suggests that berberine can inhibit cytochrome P450 2C9 (CYP2C9) activity and reduce metabolism of losartan. Theoretically, phellodendron might also inhibit the metabolism of losartan.

Likelihood Possible Evidence D
Metformin (Glucophage)

Theoretically, phellodendron might increase the therapeutic and adverse effects of metformin.
Phellodendron contains berberine. In vitro and animal studies show that berberine can increase the systemic exposure and half-life of metformin, potentially increasing metformin's effects and side effects. This interaction seems to be most apparent when berberine is administered 2 hours prior to metformin. Taking berberine and metformin at the same time does not appear to increase systemic exposure to metformin. It is unclear if phellodendron might have this same effect.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, phellodendron might reduce metabolism of midazolam, which might increase the risk of severe adverse effects.
Phellodendron contains berberine. Preliminary clinical research shows that berberine can inhibit cytochrome P450 3A4 (CYP3A4) activity and reduce metabolism of midazolam. Theoretically, phellodendron might also inhibit the metabolism of midazolam.

Likelihood Possible Evidence D
Pentobarbital (Nembutal)

Theoretically, phellodendron might increase the sedative effect of pentobarbital.
Phellodendron contains berberine. Animal research shows that berberine can prolong pentobarbital-induced sleeping time. Theoretically, phellodendron might increase the sedative effects of pentobarbital.

Likelihood Possible Evidence D
Tacrolimus (Prograf)

Theoretically, phellodendron might increase blood levels of tacrolimus.
Phellodendron contains berberine. In a 16-year-old patient with idiopathic nephrotic syndrome who was being treated with tacrolimus 6.5 mg twice daily, intake of berberine 200 mg three times daily increased the blood concentration of tacrolimus from 8 to 22 ng/mL. Following a reduction of the tacrolimus dose to 3 mg daily, blood levels of tacrolimus decreased to 12 ng/mL. It is unclear if phellodendron might have this same effect.

Likelihood Possible Evidence D
Monograph

Phellodendron: Uses, Safety & Side Effects

Medically reviewed by · Reviewed July 2026 ·
The bottom line

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.

Phellodendron
Scientific name
Phellodendron amurense
Family
Rutaceae
Part used
Bark (cortex)
Common forms
Capsules, tablets, powders, tinctures, and dried bark used in teas or decoctions; often combined with other herbs
People commonly use it for
  • Digestive complaints and diarrhea
  • Inflammation and joint discomfort
  • Stress and weight management (in combination products)
  • Skin conditions (topical, traditional)
  • Antimicrobial support

Popular and traditional uses — not proof it works. See “Uses & effectiveness” below for the evidence.

Safety at a glance
OverallUse caution

Generally used short-term in traditional medicine, but human safety data are limited.

PregnancyBest avoided

Berberine-containing herbs may not be safe in pregnancy, so avoid use.

BreastfeedingLikely Unsafe

When used orally. The berberine constituent of phellodendron and other harmful constituents can be transferred to the infant through breast milk.

Read the full breastfeeding detail

Pregnancy & breastfeeding ratings are from Natural Medicines (Therapeutic Research Center). Safety guidance is general; always confirm with your pharmacist or doctor for your situation.

Jump to a section

Overview

Phellodendron comes from the bark of the Amur cork tree (Phellodendron amurense), a deciduous tree native to China, Korea, and Japan. In traditional Chinese medicine the bark is known as Huang Bai and has been used for hundreds of years.

The bark is usually dried and made into teas, powders, tinctures, capsules, or tablets. It is often combined with other herbs in formulas rather than used alone. Some modern supplements pair Phellodendron with magnolia bark and market the blend for stress or weight management.

How it works

Phellodendron bark contains plant alkaloids, most notably berberine, along with compounds such as palmatine and jatrorrhizine. In laboratory studies, berberine shows antimicrobial, anti-inflammatory, and antioxidant activity, and it may affect blood sugar and fat metabolism.

It is important to understand that these mechanisms are mostly based on test-tube and animal research. The amounts and effects seen in a lab dish do not always match what happens in the human body, so these proposed actions should be viewed as possible rather than proven.

Effectiveness

Does Phellodendron work?

Here’s what the research actually shows for each use — graded by Natural Medicines and reviewed by .

Evidence overview · 10 uses evaluated
10 Insufficient evidence
How to read these evidence grades

Natural Medicines’ 7-point scale. We show each rating’s label word-for-word.

1EffectiveStrong, consistent evidence it works.
2Likely EffectiveGood evidence, though not yet conclusive.
3Possibly EffectiveSome evidence suggests a benefit.
4Possibly IneffectiveSome evidence it may not help.
5Likely IneffectiveFairly strong evidence it doesn’t help.
6IneffectiveStrong evidence it doesn’t work.
7Insufficient Reliable Evidence to RateToo little research to say either way.

For Phellodendron, current evidence isn’t strong enough to rate any specific use. The conditions it has been studied for are listed below.

Also studied for 10 conditions — evidence insufficient to rate
Insufficient Reliable Evidence To Rate Acne
Rating & evidence shown verbatim from Natural Medicines

It is unclear if topical phellodendron is beneficial in patients with acne.

Insufficient Reliable Evidence To Rate Benign prostatic hyperplasia (BPH)
Rating & evidence shown verbatim from Natural Medicines

Oral phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Diabetes
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral phellodendron for diabetes, there is insufficient reliable information about the clinical effects of phellodendron for this purpose.

Insufficient Reliable Evidence To Rate Diabetic foot ulcers
Rating & evidence shown verbatim from Natural Medicines

Topical phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Obesity
Rating & evidence shown verbatim from Natural Medicines

Oral phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Osteoarthritis
Rating & evidence shown verbatim from Natural Medicines

Oral phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Peptic ulcers
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral phellodendron for peptic ulcers, there is insufficient reliable information about the clinical effects of phellodendron for this purpose.

Insufficient Reliable Evidence To Rate Stress
Rating & evidence shown verbatim from Natural Medicines

Oral phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Insufficient Reliable Evidence To Rate Tuberculosis
Rating & evidence shown verbatim from Natural Medicines

Although there has been interest in using oral phellodendron for tuberculosis, there is insufficient reliable information about the clinical effects of phellodendron for this purpose.

Insufficient Reliable Evidence To Rate Wound healing
Rating & evidence shown verbatim from Natural Medicines

Topical phellodendron has only been evaluated in combination with other ingredients; its effect when used alone is unclear.

Source & disclaimer. Effectiveness ratings and evidence summaries are provided by Natural Medicines (Therapeutic Research Center) and shown as licensed. Where Natural Medicines hasn’t rated a use, HelloPharmacist’s pharmacists may add their own reviewed rating and evidence (each such entry is labeled). This is educational information, not medical advice — talk with your pharmacist or doctor before starting, stopping, or changing a supplement.

Safety & precautions

Phellodendron has a long history of traditional use, but rigorous human safety data are limited. Because it contains berberine, people with certain health conditions should be careful and check with a healthcare professional first.

There have been reports linking some Phellodendron-containing combination products to liver problems. People with liver disease, those taking medicines processed by the liver, and anyone with low blood sugar or blood pressure concerns should use caution.

Pregnancy: Avoid. Berberine-containing herbs are generally not considered safe during pregnancy. Breastfeeding: Avoid. Berberine can transfer to infants and may cause harm, so do not use while nursing. Always speak with your pharmacist or doctor before starting Phellodendron, especially if you take other medications.

Side effects

Reported side effects are not well documented but may include stomach upset, nausea, diarrhea, or cramping, especially at higher amounts. Some people may have allergic reactions.

A more serious concern is the possibility of liver injury, which has been reported with some products containing Phellodendron. Stop using it and seek medical care if you notice yellowing of the skin or eyes, dark urine, severe stomach pain, or unusual tiredness.

Phellodendron: Reported Adverse Effects

Documented safety reports on Phellodendron from the evidence-graded Natural Medicines (TRC Healthcare) database, shown word-for-word from the licensed record.

Reports by condition
Antidepressant-induced sexual dysfunction Genitourinary

Orally, a combination product containing extracts of phellodendron plus magnolia has been associated with one report of sexual dysfunction in one clinical trial. However, it is unknown if this is related to phellodendron or some other factor.

  1. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.
  2. Kalman DS, Feldman S, Feldman R, et al. Effect of a proprietary magnolia and phellodendron extract on stress levels in healthy women: a pilot, double-blind, placebo-controlled clinical trial. Nutr J 2008;7:11.
Cluster headache Neurologic/CNS

Orally, a combination product containing extracts of phellodendron plus magnolia has been associated with single reports of shaking hands, perilabial numbness, fatigue, and headache in clinical research. However, it is unknown if this is related to phellodendron or some other factor.

  1. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.
  2. Kalman DS, Feldman S, Feldman R, et al. Effect of a proprietary magnolia and phellodendron extract on stress levels in healthy women: a pilot, double-blind, placebo-controlled clinical trial. Nutr J 2008;7:11.
Dyspepsia Gastrointestinal

Orally, a combination product containing extracts of phellodendron plus magnolia has been associated with one report of heartburn in one clinical trial. However, it is unknown if this is related to phellodendron or some other factor.

  1. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.
  2. Kalman DS, Feldman S, Feldman R, et al. Effect of a proprietary magnolia and phellodendron extract on stress levels in healthy women: a pilot, double-blind, placebo-controlled clinical trial. Nutr J 2008;7:11.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

Adverse-effects data: Natural Medicines, Therapeutic Research Center

Dosing

There is no well-established, standardized dose of Phellodendron for any health condition. Products vary widely in strength and may contain other herbs, which makes general dosing advice difficult.

If you choose to use it, follow the directions on the product label and do not exceed the recommended amount. Because quality and content can differ between brands, it is best to talk with a pharmacist or doctor before starting, and to choose products from reputable manufacturers.

Pregnancy & Breastfeeding

Phellodendron & Breastfeeding

Likely Unsafe

When used orally. The berberine constituent of phellodendron and other harmful constituents can be transferred to the infant through breast milk.

  1. Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate 1993;63:201-8.
DISCLAIMER: This tool is intended for informational purposes only, and should not be interpreted as specific medical advice. Patients should consult with a qualified healthcare provider before making decisions about therapies and/or health conditions.

© 2026 Therapeutic Research Center

Pregnancy & lactation ratings: Natural Medicines, Therapeutic Research Center

References & further reading

The 22 references that drive our Phellodendron monograph and interaction data, from the evidence-graded Natural Medicines (TRC Healthcare) database. Citations with a link open the study on PubMed or the publisher’s site.

  1. Chan E. Displacement of bilirubin from albumin by berberine. Biol Neonate 1993;63:201-8. PubMed
  2. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
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  4. Garrison R, Chambliss WG. Effect of a proprietary Magnolia and Phellodendron extract on weight management: a pilot, double-blind, placebo-controlled clinical trial. Altern Ther Health Med 2006;12:50-4.
  5. Zhang Y, Li X, Zou D, et al. Treatment of type 2 diabetes and dyslipidemia with the natural plant alkaloid berberine. J Clin Endocrinol Metab 2008;93:2559-65. PubMed
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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.

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

Brand directory

Brands that make products with Phellodendron

114 brands in our database make a supplement containing Phellodendron.

Product directory

Supplement products with Phellodendron

393 products in our database contain Phellodendron. Open any to see its full ingredient list and every drug interaction we check.

intraMAX 2.0 Peach Mango Flavor by Drucker Labs Liquid 32 fl. Oz. · 946 mL Off market View ingredients & interactions Jet Lag Rapid Reset by Elevate Recovery Supplements Capsule 60 Capsule(s) Off market View ingredients & interactions Levare by Ultimaxx Tablet Or Pill 90 Tablet(s) · 600 mg Off market View ingredients & interactions Liporexall PM by Savant Nutrition Capsule 60 Capsule(s) Off market View ingredients & interactions Menopause Formula by VitaCeutical Labs Capsule 30 Vegetarian Capsule(s) Off market View ingredients & interactions Menopause Formula by Vitamer Laboratories Capsule 30 Vegetarian Capsule(s) Off market View ingredients & interactions Menopause Formula by Vitamer Laboratories Capsule 30 Vegetarian Capsule(s) Off market View ingredients & interactions Menopause Support Formula by Anabolic Laboratories Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Menopause Support Formula by Anabolic Laboratories Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Metabolic Management Pack by Douglas Laboratories Other (e.g. Tea Bag) 60 Pack(s) Off market View ingredients & interactions Metabolic Management Pack by Douglas Laboratories Other (e.g. Tea Bag) 30 Pack(s) Off market View ingredients & interactions Metabolic Management Pack by Douglas Laboratories Other (e.g. Tea Bag) 60 Pack(s) Off market View ingredients & interactions Metabolic Management Pack by Douglas Laboratories Other (e.g. Tea Bag) 60 Pack(s) Off market View ingredients & interactions Multi Complex Evening by Thorne FX Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Multi-Vitamin Elite - P.M. by Thorne Capsule 90 Capsule(s) Off market View ingredients & interactions Multi-Vitamin Elite P.M. by Thorne Capsule 90 Capsule(s) Off market View ingredients & interactions Multi-Vitamin Elite P.M. by EXOS Performance Nutrition Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Multi-Vitamin Elite P.M. by EXOS Performance Nutrition Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Multi-Vitamin Elite P.M. by EXOS Performance Nutrition Capsule 90 Vegetarian Capsule(s) Off market View ingredients & interactions Natural Cortisol Balance by Life Extension Capsule 30 Vegetarian Capsule(s) Off market View ingredients & interactions Natural Glucocil by Neuliven Health Softgel Capsule 120 Easy-to-Swallow Softgel(s) Off market View ingredients & interactions Natural Glucocil by Neuliven Health Softgel Capsule 120 Easy To Swallow Softgel(s) Off market View ingredients & interactions Nature's Cortisol Formula by Nature's Sunshine Capsule 90 Capsule(s) Off market View ingredients & interactions Night by Life Time Fitness Capsule 90 Capsule(s) Off market View ingredients & interactions
Pharmacist Counseling Corner

Phellodendron: Common Questions

What is Phellodendron used for, and does it work?
People use Phellodendron for a range of reasons, but according to the Natural Medicines database the current clinical evidence is insufficient to confirm it works for the specific conditions it has been studied for. See the graded list on this page, and talk to your pharmacist or doctor before relying on it for any condition.
Does Phellodendron interact with prescription medications?
Yes. We list 1160 medications with a known interaction with Phellodendron. Use the checker above to see how Phellodendron interacts with a specific drug.
How are Phellodendron interactions rated?
Each interaction is graded major, moderate, or minor based on how clinically significant it is and the strength of the evidence behind it. Major interactions are the most serious and are best avoided, or used only under close professional supervision.
Is it safe to take Phellodendron with my medications?
It depends on the specific medication. Some combinations are fine, while others call for monitoring, timing changes, or should be avoided. Check your exact drug above and confirm with your pharmacist or doctor before starting, stopping, or changing anything.
Where does this Phellodendron interaction information come from?
Our interaction data is built on the Natural Medicines database — an evidence-graded reference for vitamins, herbs, and supplements — and is reviewed by licensed HelloPharmacist pharmacists, who may add clinical context.
What is Phellodendron used for?
It is a traditional Chinese medicine bark used for digestive problems, inflammation, skin conditions, and as an antimicrobial. More recently it appears in supplements for stress and weight, but solid human evidence is limited.
Is Phellodendron the same as berberine?
No. Phellodendron is the bark of the Amur cork tree, and berberine is one of the main active compounds it contains. Berberine is also found in other plants like goldenseal and barberry.
Is Phellodendron safe to take?
It has a long history of traditional use, but human safety data are limited and some products have been linked to liver problems. Use caution and check with your pharmacist or doctor first.
Can I take Phellodendron while pregnant or breastfeeding?
No. It contains berberine, which is generally considered unsafe during pregnancy and breastfeeding, so it is best to avoid it.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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