Drug & supplement interaction

Phellodendron + Nebivolol Hydrochloride, Valsartan

Nebivolol Hydrochloride, Valsartan brand name: Byvalson.

Moderate Interaction
The bottom line Moderate

Nebivolol Hydrochloride, Valsartan falls into 3 drug categories that Phellodendron can interact with; the most serious is rated moderate. Theoretically, phellodendron might have additive effects with antihypertensive drugs.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
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Interaction report

Phellodendron and Nebivolol Hydrochloride, Valsartan

These two interact in 3 distinct ways. Each one is explained separately below.

Why Are There 3 Interactions?

Phellodendron interacts with whole categories of medication. Nebivolol Hydrochloride, Valsartan falls into 3 of those categories, so it can interact with Phellodendron in 3 different ways. We’ve listed each one below — your overall risk is driven by the most serious of them (Moderate).

Moderate

ANTIHYPERTENSIVE DRUGS

1 of 3

Why this applies to Nebivolol Hydrochloride, Valsartan

Nebivolol Hydrochloride, Valsartan falls under ANTIHYPERTENSIVE DRUGS — the group Phellodendron interacts with.

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.
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

Byvalson combines two blood pressure medicines: nebivolol (a beta blocker) and valsartan (an ARB). Phellodendron contains berberine, which on its own may gently nudge blood pressure downward. So the concern here is simple addition: stacking a supplement that lowers blood pressure on top of two medicines that already do the same job.

If your pressure drops too far, you might feel dizzy, lightheaded, unusually tired, or wobbly when standing up quickly. I want to be honest though, this is a theoretical interaction based mostly on animal studies and how these things work, not strong human proof. It's worth a heads-up rather than alarm. Don't stop anything on your own. Check in with your pharmacist or doctor before adding phellodendron, and keep an eye on your home blood pressure readings.

References
  1. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
  2. Chun YT, Yip TT, Lau KL, and et al. A biochemical study on the hypotensive effect of berberine in rats. Gen Pharmac 1979;10:177-182. PubMed
  3. Lan J, Zhao Y, Dong F, et al. Meta-analysis of the effect and safety of berberine in the treatment of type 2 diabetes mellitus, hyperlipemia and hypertension. J Ethnopharmacol. 2015;161:69-81. PubMed
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 3

Nebivolol Hydrochloride, Valsartan also falls under 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.
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

Byvalson combines two medicines, and one of them, nebivolol (a beta blocker), is cleared from your body mainly by a liver enzyme called CYP2D6. Phellodendron contains berberine, which lab studies suggest can slow that same enzyme down. In theory, that could let nebivolol build up a bit higher than usual.

If that happened, you might notice stronger blood-pressure-lowering effects: dizziness, lightheadedness when standing, unusual tiredness, or a slower heart rate. Keep in mind this is a theoretical concern based on how berberine behaves in test tubes, not proven harm in people. The valsartan part isn't affected this way. Still, before adding phellodendron, check with your pharmacist or doctor, and let them know if you feel newly dizzy or sluggish.

References
  1. Chatterjee P, Franklin MR. Human cytochrome p450 inhibition and metabolic-intermediate complex formation by goldenseal extract and its methylenedioxyphenyl components. Drug Metab Dispos 2003;31:1391-7. PubMed
  2. 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
  3. 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
Moderate

CYTOCHROME P450 2C9 (CYP2C9) SUBSTRATES

3 of 3

Nebivolol Hydrochloride, Valsartan also falls under 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.
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 basic idea with Byvalson (which combines nebivolol, a beta-blocker, and valsartan, a blood pressure pill). Phellodendron contains berberine, and early research hints that berberine may slow down a liver enzyme called CYP2C9. The valsartan part of this combo is handled in part by that pathway, so in theory the herb could let a bit more of it linger in your system.

If that happened, you might notice your blood pressure running lower than usual, with effects like dizziness, lightheadedness, fatigue, or a slow pulse. I want to be honest though: this is theoretical, based on how the chemistry could behave, not on real patient reports. It may never cause a problem. Still, since blood pressure changes can sneak up on you, check with your pharmacist or doctor before adding this supplement.

References
  1. 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

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 1,159 moderate known drug interactions in our database — the Nebivolol Hydrochloride, Valsartan one above is among them. If you take anything else, check it against the full list below.

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.

Everything else you take

See Every Supplement That Interacts With Nebivolol Hydrochloride, Valsartan

This page covers Phellodendron only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Nebivolol Hydrochloride, Valsartan page lists 213 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: Activated Charcoal (major), American Hellebore (major), American Mistletoe (major), Indian Snakeroot (major) and Tyramine (major).

By severity: 5 major · 173 moderate · 35 minor.

From our pharmacist’s overview on the Nebivolol Hydrochloride, Valsartan page

“Nebivolol with valsartan (Byvalson) packs two blood pressure medicines into one pill, and I would treat this list with genuine care, especially its handful of serious entries. Most of the interactions tug on blood pressure itself, some deepening the drop until dizziness or fainting becomes a risk, others, tyramine among them, pushing p…”

Reviewed by 2 · Jul 18, 2026

Open the Nebivolol Hydrochloride, Valsartan 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 Nebivolol Hydrochloride, Valsartan 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 Nebivolol Hydrochloride, Valsartan 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%

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

29 days ago today
Medication Nebivolol Hydrochloride, Valsartan
Steady interest

#1,428 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
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
1,159Moderate
0Minor
1,670No known interaction
Moderate

1,159 interactions

Showing 60 of 1,159 moderate interactions — see all 1,159 on the Phellodendron page.

No interaction 1,670 drugs checked — show the list
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

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Pharmacist Counseling Corner

Taking Phellodendron and Nebivolol Hydrochloride, Valsartan Together: Common Questions

Can you take Phellodendron with Nebivolol Hydrochloride, Valsartan?
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.
Why are there 3 interactions listed for Phellodendron and Nebivolol Hydrochloride, Valsartan?
Nebivolol Hydrochloride, Valsartan belongs to more than one drug category, and Phellodendron interacts with each of those categories a little differently. We list every one so nothing is missed — your overall risk is driven by the most serious of them.
How serious is the Phellodendron and Nebivolol Hydrochloride, Valsartan 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

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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.