Know2eat

Oregon grape

Mahonia aquifolium

Herbs & Botanicals

What oregon grape may help with

Ranked by how strong the human evidence is — best supported first.

Best supportedSkin structure and hydrationLimited evidence· 2 sources

Then, in order

About Oregon grape

Root and stem bark of a Pacific Northwest shrub, sold as a berberine-containing alternative to goldenseal and as a topical cream for psoriasis.

The only human evidence of substance is topical: several trials of a 10% Mahonia cream in plaque psoriasis report modest improvement, generally less than standard therapy. Oral use rests on berberine content, which brings berberine’s interaction profile with it and none of berberine’s own trial data at the doses supplied.

Sold as
Topical cream, Root tincture, Capsule, Dried root
Standardised to
Topical products commonly 10% extract; oral products rarely state alkaloid content — a product without this marker may not resemble what was studied.
Also known as
Berberis aquifolium, Mountain grape, Holly-leaved barberry

What the research used

The amounts, forms and durations published trials of Oregon grape actually administered.

These are the amounts published trials administered — not a recommendation, and not a dose to copy. Trial participants were screened, supervised and given a characterised preparation. What is in a retail bottle is frequently not what was studied, and the amount that suits one person is not general advice.

  • Studied for Plaque psoriasis, topical

    10 %

    Limited

    Topical cream applied twice daily · 4–12 weeks

    Applied to skin rather than swallowed, so the number is a concentration, not an intake. Trials were small and several were funded by the cream’s manufacturer.

  • Studied for Oral use

    500 mg

    Not enough

    Root extract capsule

    Oral trial dosing is not established for Oregon grape. Retail amounts are carried over from other berberine-containing herbs rather than from any study of this plant.

This is general information about food, not medical advice. It cannot diagnose, treat or replace guidance from a clinician who knows your history.

When it was taken

Each window says whether a trial compared it against an alternative, or whether it is convention and pharmacology. Most timing advice is the second kind.

None of the timings below were directly compared in a trial. They reflect how the research happened to dose, or what the pharmacology implies — which is not the same as a timing being better.

  • Any time

    Not enough

    Topical trials applied it twice daily; no oral timing has been examined.

    Timing was not directly compared. This reflects convention or how the compound behaves in the body, not a trial showing this window works better.

The evidence in depth

Best supported: Limited

What each association actually rests on, and the papers behind it. A rating describes the state of the research, not how promising the supplement sounds. How we rate evidence.

Skin structure and hydration

Skin Health
Limited evidence

Some trials of a topical Mahonia cream report reduced plaque severity in mild to moderate psoriasis, with effects smaller than conventional therapy. The studies are small and mostly manufacturer-supported.

Limited evidence. Early human work, or mostly lab and animal research.

View the 2 sources

Deep research mode adds each paper’s own conclusion and stated limitations.

Blood glucose response

Blood Sugar & Metabolic Health
Not enough evidence

There is not enough human research on Oregon grape and blood glucose. Claims are inferred from berberine research using isolated berberine at doses this plant material does not supply.

Not enough evidence. Not enough human research to say anything useful yet.

No source is attached to this association yet, so it is rated not enough evidenceby default. It is listed because people commonly ask about it — not because there is evidence for it.

Things to know

Interactions, contraindications and dose limits, most serious first. Concentrated extracts interact with medication in ways the whole plant does not, so this section carries more weight here than it does on a food page.

  • Interaction

    Berberine-type drug interactions

    Interacts withCiclosporin, statins, CYP3A4 and P-glycoprotein substrates

    The berberine in Oregon grape inhibits CYP3A4 and P-glycoprotein, which can raise levels of many prescription drugs including ciclosporin, some statins and calcium channel blockers.

  • Avoid

    Pregnancy, breastfeeding and newborns

    As with any berberine-containing plant, it is contraindicated in pregnancy and breastfeeding because of the risk of bilirubin displacement and kernicterus in infants.

  • Worth knowing

    Skin irritation with the cream

    Burning, itching and rash at the application site are the commonly reported effects of topical Mahonia preparations.

  • Worth knowing

    Sold without pre-market review

    Neither the oral nor the topical supplement version is assessed by a US regulator for efficacy or safety before sale.

Evidence ratings on this page: 1 limited evidence, 1 not enough evidence.

Supplements are sold in the US without pre-market review of efficacy or safety. Nothing on this page is a recommendation to take Oregon grape, or a dose to follow.