Drug & supplement interaction

Oregon Grape + Morphine Sulfate

Morphine Sulfate brand names: MS Contin, Kadian, Avinza, Morphabond, Arymo ER.

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

Morphine Sulfate falls into 3 drug categories that Oregon Grape can interact with; the most serious is rated moderate. Theoretically, Oregon grape might increase the sedative effects of CNS depressants.

Read the full interaction report
SeverityModerate
LikelihoodPossible
Interactions3
EvidenceD
What do Severity, Likelihood & Evidence mean?
Know someone taking this? Share
Facebook Post Reddit Email
On this page
Interaction report

Oregon Grape and Morphine Sulfate

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

Why Are There 3 Interactions?

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

Moderate

CNS DEPRESSANTS

1 of 3

Why this applies to Morphine Sulfate

Morphine Sulfate falls under CNS DEPRESSANTS — the group Oregon Grape interacts with.

Theoretically, Oregon grape might increase the sedative effects of CNS depressants.
Animal research suggests that berberine, a constituent of Oregon grape, can have sedative effects.
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 simple version: morphine is already a strong opioid that slows down your brain and body, causing drowsiness, slowed breathing, and sometimes confusion. Oregon grape contains berberine, and in animal studies that compound showed mild sedative effects of its own. So the worry is that stacking the two could add up and make you sleepier or more sluggish than morphine alone would.

I'll be honest with you, this is a theoretical concern based on lab and animal research, not human cases, so it's likely a modest effect at most. Still, because morphine's heaviest risk is breathing that slows too much, it's worth a quick check. Before adding Oregon grape, talk with your pharmacist or doctor so they can keep an eye on your sedation.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Janbaz KH, Gilani AH. Studies on preventive and curative effects of berberine on chemical-induced hepatotoxicity in rodents. Fitoterapia 2000;71:25-33.. PubMed
  2. Shanbhag, S. M., Kulkarni, H. J., and Gaitonde, B. B. Pharmacological actions of berberine on the central nervous system. Jpn.J Pharmacol 1970;20(4):482-487. PubMed
  3. Peng, W. H., Hsieh, M. T., and Wu, C. R. Effect of long-term administration of berberine on scopolamine-induced amnesia in rats. Jpn J Pharmacol 1997;74(3):261-266. DOI
  4. Sabir M and Bhide NK. Study of some pharmacological actions of berberine. Ind J Physiol & Pharmac 1971;15(3):111-132.
Moderate

CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES

2 of 3

Morphine Sulfate also falls under CYTOCHROME P450 2D6 (CYP2D6) SUBSTRATES.

Theoretically, Oregon grape might increase serum levels of drugs metabolized by CYP2D6.
In vitro research and preliminary clinical evidence suggest that berberine, a constituent of Oregon grape, can inhibit cytochrome P450 2D6 (CYP2D6).
Severity Moderate Likelihood Possible Evidence B

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 honest picture: this concern is mostly theoretical for morphine. The worry on file is that berberine, found in Oregon grape root, may block an enzyme called CYP2D6. But morphine isn't really cleared by CYP2D6 in a meaningful way. It's mostly handled by a different process (glucuronidation through UGT enzymes), so blocking CYP2D6 isn't likely to make morphine build up the way it might with some other opioids.

So I wouldn't expect a big change in how morphine works from this combo. Still, opioids carry real risks like drowsiness, slowed breathing, and constipation, so if you ever feel unusually sleepy or foggy, take it seriously. Before adding concentrated Oregon grape supplements, just run it by your pharmacist or doctor to be safe.

Contact Dr. Brian directly if you have additional questions on this interaction
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

P-GLYCOPROTEIN SUBSTRATES

3 of 3

Morphine Sulfate also falls under P-GLYCOPROTEIN SUBSTRATES.

Theoretically, Oregon grape might increase serum levels of drugs that are P-glycoprotein (P-gp) substrates.
In vitro research suggests that Oregon grape extracts inhibit P-gp efflux.
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 morphine and Oregon grape. Your body uses a kind of cellular pump called P-glycoprotein to move morphine around and help limit how much gets into your system. The berberine in Oregon grape can, at least in lab dishes, slow that pump down. If that happened in real life, a bit more morphine could stay in your body, which in theory might mean stronger effects: more drowsiness, dizziness, constipation, and slowed breathing.

The important caveat: this is based only on test-tube research, not on people, so we really don't know if it matters in practice. Morphine is still a strong opioid, though, so it's worth a quick chat with your pharmacist or doctor before adding Oregon grape, rather than making any changes on your own.

Contact Dr. Brian directly if you have additional questions on this interaction
References
  1. Fan Y, Zhou Z, Zhang L. Effect of Oregon grape root extracts on P-glycoprotein mediated transport in in vitro cell lines. J Pharm Pharm Sci 2024;26:11927. 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

Oregon Grape Also Interacts With Other Medications

Oregon Grape has 1,218 moderate known drug interactions in our database — the Morphine Sulfate one above is among them. If you take anything else, check it against the full list below.

Moderate 1,218 No known interaction 1,612 (incl. Morphine Sulfate)
Taking anything else?

Check Another of Your Medications Against Oregon Grape

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

From our Q&A

Questions About Oregon Grape or Morphine Sulfate

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

This page covers Oregon Grape only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Morphine Sulfate page lists 172 supplements it has a documented interaction with, worst first, each one explained.

The most serious there right now: 1,4-butanediol (major), Activated Charcoal (major), Beer (major), Gamma-hydroxybutyrate (ghb) (major) and Kava (major).

By severity: 8 major · 138 moderate · 26 minor.

From our pharmacist’s overview on the Morphine Sulfate page

“With morphine sulfate (MS Contin, Kadian, Avinza), an opioid powerful enough to slow breathing on its own, this list warrants genuine respect. Of the 172 supplements and foods on file, 8 carry a major rating, and most of those pile extra sedation onto a drug that already sedates.”

Reviewed by 2 · Jul 18, 2026

Open the Morphine Sulfate interaction page

One more smart check

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

We hold 740 real supplement products containing Oregon Grape, each one broken down to its full ingredient list — and combination products often carry several ingredients besides Oregon Grape. Your product may carry other ingredients that interact with Morphine Sulfate too, on top of Oregon Grape — 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 Oregon Grape and Morphine Sulfate 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 Oregon Grape
Top 25%

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

29 days ago today
Medication Morphine Sulfate
Top half

#1,014 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 Oregon Grape

What is Oregon Grape?

Oregon Grape
  • Psoriasis (topical)
  • Eczema and other skin conditions
  • Digestive upset
  • Mild skin infections
  • General 'detox' or tonic use

Oregon grape is a shrub whose root contains berberine and related compounds. The strongest (though still modest) evidence is for topical creams that may slightly ease psoriasis; evidence for other uses is limited. Talk with your pharmacist or doctor before using it, and avoid it during pregnancy and breastfeeding.

Read the full Oregon Grape monograph & all interactions
Medication

About Morphine

What Is Morphine Used For?

Brand names: MS Contin, Kadian, Avinza, Morphabond, Arymo ER

Morphine is used for pain that is severe enough to need an opioid and that other treatments cannot control well. It is meant for people who have not done well on, or cannot tolerate, other options.

Some uses depend on the product. Morphine sulfate tablets treat acute pain in adults and in children weighing at least 50 kg, and chronic pain in adults. Morphine oral solution (2 mg/mL and 4 mg/mL) treats acute and chronic pain in adults and acute pain in children 2 years and older. The 20 mg/mL oral solution is only for opioid-tolerant adults. Extended-release capsules and tablets, including MS Contin, are for severe, persistent pain that needs daily, long-term opioid treatment. Duramorph and preservative-free morphine injection can be given by vein, or into the epidural or intrathecal space (around the spinal cord). Infumorph and Mitigo are only for continuous epidural or intrathecal infusion for intractable chronic pain.

See full Morphine drug information
Keep checking

Other Drugs & Oregon Grape

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

0Major
1,218Moderate
0Minor
1,611No known interaction
1,218 Moderate 1,611 No interaction
Moderate

1,218 interactions

Showing 60 of 1,218 moderate interactions — see all 1,218 on the Oregon Grape page.

No interaction 1,611 drugs checked — show the list

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

Showing the 60 most looked-up of 1,611 medications checked with no known interaction — see the full Oregon Grape list.

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

Can you take Oregon Grape with Morphine Sulfate?
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 Oregon Grape and Morphine Sulfate?
Morphine Sulfate belongs to more than one drug category, and Oregon Grape 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 Oregon Grape and Morphine Sulfate 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 Morphine Sulfate and Oregon Grape?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.