Berberine

Berberine alkaloid

The clearest current evidence is for metabolic syndrome and type 2 diabetes or glucose control. Cholesterol and weight findings still look promising but now sit one tier lower, while fatty liver (NAFLD) and PCOS are more mixed. Poor oral bioavailability still explains why trials often pair berberine with absorption-focused formulations.

What the research says

Each row is a different health effect. A means the support looks strongest, B likely helpful, C mixed or modest, and — not enough human evidence yet.

A · Strong evidence of benefit
A
Metabolic syndrome & insulin resistance
Consistent improvements in insulin sensitivity and fasting insulin across 13 reviews. Effects hold up across type 2 diabetes, prediabetes, and metabolic syndrome populations.
27 papers · 12 research reviews
A
Type 2 diabetes & blood glucose
All 6 reviews positive. Lowers fasting glucose and long-term blood-sugar markers — comparable to metformin in some head-to-head trials. Held at B because only 3 reviews pass the quality filter.
21 papers · 6 research reviews
B · Likely helpful
B
Cholesterol and blood fats
Meaningfully lowers "bad" cholesterol (LDL) and triglycerides, with modest gains in "good" cholesterol (HDL). Effects are larger when baseline inflammation is high.
28 papers · 13 research reviews
B
Weight & body composition
3 of 9 reviews positive, 6 mixed. Modest 1–3 kg reductions where present. Best characterized as a secondary benefit of metabolic improvement, not a primary weight-loss agent.
23 papers · 8 research reviews
C · Mixed or limited evidence
C
NAFLD (fatty liver)
Large reductions in liver enzymes, liver fat, and metabolic markers across pooled trials. Effects appear at 1,000–1,500 mg/day for 12+ weeks.
14 papers · 3 research reviews
C
PCOS (polycystic ovary syndrome)
Comparable to metformin on testosterone, insulin sensitivity, and ovulation, with significantly fewer digestive side effects. Nearly doubles pregnancy rates when combined with conventional treatment.
8 papers · 3 research reviews

Quick facts

Dose, form and timing based on trials in the database.

Typical dose
500–1,500 mg/day split into 2–3 doses
Best taken
With meals (improves absorption and reduces stomach upset)
Form
Berberine HCl is standard. Dihydroberberine and bioavailability-enhanced forms (often combined with silymarin) absorb up to 5× better and appeared more often in positive trials
Common side effects
Digestive issues (constipation, diarrhea, abdominal discomfort) — typically mild, dose-dependent, and reduced when taken with meals
Drug interactions
Inhibits CYP3A4 — can elevate levels of statins, blood thinners, and many other prescription drugs. Check with a doctor if on any prescription medication
Dose range in trials
600–2,000 mg/day across the metabolic outcome trials reviewed

Quality-verified products

Products that pass third-party quality testing.

Product quality data coming soon

Product recommendations are being built from USP Verified, NSF Certified, and Labdoor test data. Products will only appear here after the supplement itself clears the evidence bar above — and only if the product passes third-party purity testing.

How we graded Berberine

Grades come from 57 unique research papers indexed from PubMed — including 27 meta-analyses, 18 systematic reviews, and 75 randomized trials. Sixty-three of 121 health-effect records were rated low-confidence due to combination products (berberine with silymarin, milk thistle, or Chinese medicine herbs where the contribution can't be isolated) or mixed human/preclinical review abstracts. Each supplement is graded by health effect using a certainty × effect matrix applied across PubMed evidence per health effect. Cochrane reviews and high-quality systematic reviews carry the most weight. From abstract-only data, "high certainty" is rare — most A grades come from moderate certainty plus consistent meaningful-positive evidence. See Methodology for full detail.

Read the full methodology → · Download all 57 citations (PDF)