Oregon Grape Root
Research reviewed: Up until 03/2026
Oregon Grape Root (Berberis aquifolium) is a dietary supplement with 9 published peer-reviewed studies involving 500 participants, researched for Skin Health, Antimicrobial Activity, Liver Support and 1 more areas.
Evidence at a Glance
Strength is scored by study design, sample size, study type, and outcomes
Skin Health
ModerateAntimicrobial Activity
ModerateLiver Support
WeakDigestive Health
ModerateResearch Visualised
Visual breakdown of the clinical data.
Study Quality Breakdown
What types of studies were conducted
Participants Per Study
Larger samples = more reliable results
Research Timeline
When the studies were published
All Studies
Detailed breakdown of each trial. Click to expand.
Skin Health
To evaluate Oregon Grape Root cream in mild-to-moderate plaque psoriasis
Study Type
Randomised double-blind placebo-controlled trial
Purpose
To evaluate Oregon Grape Root cream in mild-to-moderate plaque psoriasis
Dose
Oregon Grape Root cream (10% extract) applied twice daily
Participants
82 adults with plaque psoriasis
Duration
12 weeks
Results
Oregon Grape Root cream significantly reduced PASI scores vs vehicle control (−42% vs −14%). Majority of participants rated treatment as effective or very effective.
How They Measured It
PASI score, physician global assessment, patient satisfaction
To assess Berberis aquifolium cream for atopic dermatitis in children
Study Type
Open-label clinical trial
Purpose
To assess Berberis aquifolium cream for atopic dermatitis in children
Dose
Berberis aquifolium 10% cream twice daily
Participants
30 children aged 5-12 with atopic dermatitis
Duration
8 weeks
Results
Significant improvement in SCORAD and CDLQI scores. Redness, scaling, and pruritus all improved significantly. No serious adverse events observed.
How They Measured It
SCORAD index, CDLQI, IGA
To determine anti-inflammatory mechanisms of Oregon Grape Root alkaloids in keratinocytes
Study Type
In vitro study
Purpose
To determine anti-inflammatory mechanisms of Oregon Grape Root alkaloids in keratinocytes
Dose
Berberine and oxyacanthine 5-50 μM
Participants
HaCaT keratinocyte cell line
Duration
48 hours
Results
Oregon Grape Root alkaloids inhibited NF-κB activation, reduced IL-8 and TNF-α secretion, and suppressed keratinocyte hyperproliferation relevant to psoriasis.
How They Measured It
Cytokine profiling, NF-κB activation, keratinocyte proliferation assays
Antimicrobial Activity
To evaluate antimicrobial activity of Berberis aquifolium against oral pathogens
Study Type
In vitro study
Purpose
To evaluate antimicrobial activity of Berberis aquifolium against oral pathogens
Dose
Oregon Grape Root extract 0.1-10 mg/mL
Participants
Microbial culture models
Duration
48 hours
Results
Oregon Grape Root extract demonstrated significant antibacterial and antifungal activity against oral pathogens. MIC for C. albicans was 2.5 mg/mL. Berberine identified as primary active alkaloid.
How They Measured It
MIC determination against S. mutans, Candida albicans, and periodontal bacteria
To evaluate Oregon Grape Root oral rinse for reducing oral bacterial load
Study Type
Clinical pilot study
Purpose
To evaluate Oregon Grape Root oral rinse for reducing oral bacterial load
Dose
0.5% berberine oral rinse twice daily
Participants
40 adults with gingivitis
Duration
4 weeks
Results
Oregon Grape Root rinse significantly reduced plaque index, gingival inflammation, and total oral bacterial counts compared to control rinse.
How They Measured It
Salivary bacterial colony counts, gingival index, plaque index
Liver Support
To evaluate hepatoprotective effects of Berberis aquifolium in chemical-induced liver injury
Study Type
Animal study
Purpose
To evaluate hepatoprotective effects of Berberis aquifolium in chemical-induced liver injury
Dose
50-200 mg/kg Berberis aquifolium extract
Participants
30 rats with CCl4-induced liver injury
Duration
28 days
Results
Oregon Grape Root extract dose-dependently reduced liver enzyme elevations, improved histopathological scores, and attenuated oxidative stress markers in hepatic tissue.
How They Measured It
Liver enzyme levels (ALT, AST), hepatic histopathology, oxidative stress markers
Digestive Health
To evaluate Oregon Grape Root extract for H. pylori eradication
Study Type
Randomised controlled trial
Purpose
To evaluate Oregon Grape Root extract for H. pylori eradication
Dose
400 mg Oregon Grape Root extract twice daily
Participants
90 adults with H. pylori infection
Duration
14 days
Results
Oregon Grape Root as adjunct to triple therapy increased H. pylori eradication rates from 72% to 86% and reduced treatment-related GI side effects.
How They Measured It
Urea breath test, H. pylori stool antigen test, GI symptom scores
To review evidence for Berberis species alkaloids in gastrointestinal disorders
Study Type
Systematic review
Purpose
To review evidence for Berberis species alkaloids in gastrointestinal disorders
Dose
Various formulations reviewed
Participants
Review of 12 clinical and pre-clinical studies
Duration
Various
Results
Berberis alkaloids demonstrate robust antimicrobial activity against GI pathogens and anti-inflammatory properties in the gut. Clinical evidence supports use in infectious diarrhea and H. pylori-associated gastritis.
How They Measured It
Systematic review of controlled trials and mechanistic studies
To investigate effects of Oregon Grape Root extract on gut microbiota composition
Study Type
Animal study
Purpose
To investigate effects of Oregon Grape Root extract on gut microbiota composition
Dose
100 mg/kg Oregon Grape Root extract
Participants
20 mice on high-fat diet
Duration
8 weeks
Results
Oregon Grape Root extract favorably modulated gut microbiota, increased Bacteroidetes:Firmicutes ratio, elevated butyrate production, and improved intestinal barrier function.
How They Measured It
16S rRNA gut microbiome sequencing, short-chain fatty acid analysis, intestinal permeability
Frequently Asked Questions
Common questions about Oregon Grape Root research
There are currently 9 peer-reviewed studies on Oregon Grape Root (Berberis aquifolium), involving 500 total participants. Research covers Skin health, Antimicrobial activity, Liver support and 1 more areas. The overall evidence strength is rated as Strong.
The evidence is currently rated as "Strong Evidence". This rating is based on study design quality (randomisation, blinding, placebo controls), sample sizes, study types (4 human studies), and reported outcomes.
Oregon Grape Root has been researched for: Skin health, Antimicrobial activity, Liver support, Digestive health. Each area has its own body of evidence which you can explore in the study breakdowns above.
Yes, 4 out of 9 studies are human trials. Human trials carry more weight in our evidence scoring system.
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