Drug & supplement interaction

Oregon Grape + Candesartan Cilexetil

Candesartan Cilexetil brand names: Atacand, Amias.

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

Oregon Grape has a moderate interaction with Candesartan Cilexetil. Theoretically, Oregon grape might increase the risk of hypotension when taken with antihypertensive drugs.

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

Oregon Grape and Candesartan Cilexetil

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

Moderate

ANTIHYPERTENSIVE DRUGS

Why this applies to Candesartan Cilexetil

Candesartan Cilexetil falls under ANTIHYPERTENSIVE DRUGS — the group Oregon Grape interacts with.

Theoretically, Oregon grape might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that berberine, a constituent of Oregon grape, can have hypotensive effects. Also, an analysis of clinical evidence suggests that taking berberine in combination with amlodipine (Norvasc) can lower systolic and diastolic blood pressure when compared with taking amlodipine alone.
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: candesartan already lowers your blood pressure by relaxing your blood vessels. Oregon grape contains berberine, which animal studies (and a small bit of human data with a different blood pressure pill) suggest may also nudge blood pressure down. Stack the two together and, in theory, your numbers could drop a little lower than expected.

If that happened, you might feel dizzy or lightheaded, especially when standing up quickly, or notice tiredness or a headache. To be clear, this is mostly theoretical and based on lab and animal work, so it's not a strong or certain effect. Still, if you're thinking about an Oregon grape supplement, check with your pharmacist or doctor first, and keep an eye on your blood pressure readings at home.

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

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 1,217 moderate known drug interactions in our database — the Candesartan Cilexetil one above is one of them. If you take anything else, check it against the full list below.

Moderate 1,217 No known interaction 1,613 (incl. Candesartan Cilexetil)
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 Candesartan Cilexetil

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 Candesartan Cilexetil, 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 Candesartan Cilexetil

This page covers Oregon Grape only. If you take other supplements — a multivitamin, a sleep aid, something for joints — the Candesartan Cilexetil page lists 138 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), Tyramine (major) and Adrafinil (moderate).

By severity: 4 major · 112 moderate · 22 minor.

Open the Candesartan Cilexetil 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 Candesartan Cilexetil 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 Candesartan Cilexetil 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%

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

29 days ago today
Medication Candesartan Cilexetil
Top 5%

#80 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 Candesartan

What Is Candesartan Used For?

Brand names: Atacand, Amias

Candesartan tablets are used to treat high blood pressure (hypertension) in adults and in children ages 1 to under 17. Lowering blood pressure reduces the risk of strokes and heart attacks.

Candesartan tablets are also used in adults with heart failure (NYHA class II–IV) with reduced heart pumping function to lower the risk of cardiovascular death and hospitalization from heart failure. Atacand is specifically studied for use alongside an ACE inhibitor for added benefit in heart failure.

See full Candesartan 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
1,217Moderate
0Minor
1,612No known interaction
1,217 Moderate 1,612 No interaction
Moderate

1,217 interactions

Showing 60 of 1,217 moderate interactions — see all 1,217 on the Oregon Grape page.

No interaction 1,612 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 1,612 medications checked with no known interaction — see the full Oregon Grape list.

See the full Oregon Grape interactions page
See every supplement checked against Candesartan Cilexetil, 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 Candesartan Cilexetil supplement interactions › Every supplement checked against Candesartan Cilexetil, ranked by severity Candesartan 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 Candesartan Cilexetil Together: Common Questions

Can you take Oregon Grape with Candesartan Cilexetil?
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 Oregon Grape and Candesartan Cilexetil 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 Candesartan Cilexetil and Oregon Grape?

Our pharmacists answer your medication & supplement questions — free.

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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.