Berberine

We evaluated 160 human studies on Berberine, including 45 randomised controlled trials and 33 meta-analyses or systematic reviews; the controlled studies include 4,809 participants in total. As of 9 October 2026.

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1. What Is Berberine? Occurrence, Origin and Forms

Berberine is a plant alkaloid from the barberry family (Berberidaceae). It occurs mainly in the bark, roots and rhizomes of several Berberis and Coptis species and is used in traditional Chinese and Ayurvedic medicine. In studies it is usually tested as a salt or as a plant extract.

Berberine occurs in barberries (Berberis), in Coptis species and in goldenseal (Hydrastis canadensis), as well as in Phellodendron. The highest levels are found in root, rhizome and bark, not in the fruit.

Berberine is obtained by extraction from root, rhizome or bark; in studies and in commerce it is usually supplied as a salt, for example as hydrochloride or sulfate. What is tested includes the pure substance, plant extracts and combinations with substances intended to change its absorption.

Forms and Preparations Studied

• Berberine hydrochloride
• Berberine sulfate
• Berberine citrate
• Dihydroberberine (derivative)
• Plant extracts from barberry bark, Coptis or goldenseal
• Combination products with absorption enhancers

Not covered on this page:

• Other alkaloids from the same plants, such as berbamine or palmatine
• Blood-sugar-lowering drugs such as metformin
• Barberry fruit and foods made from it, such as juice or jam

2. What Does Berberine Do? Results by Area

How to read the table: counted are human studies whose results concern the area. “High” means at least one meta-analysis and two controlled studies showing improvement, or at least three controlled studies of which three quarters show improvement, with at least 300 participants in total. “Moderate” means at least two controlled studies showing improvement, as a majority, or one meta-analysis alongside controlled studies. “Low” means one controlled study showing improvement. Where an area has no controlled study, the strength of evidence is at most “low” (result “reviews only” or “observational data only”). Everything else is “unclear”. A study counts as showing improvement when at least half of its outcomes in this area improved. Reviews of combination products do not count as meta-analyses; results that only describe side effects or shares of users do not count as an effect. The same study is counted only once.

3. What the Studies Show in Detail

Berberine, Blood Sugar and Insulin: Human Studies

In diabetes and related metabolic disorders, fasting glucose decreased more strongly in meta-analyses on berberine and barberry preparations than under the control 14182737. HbA1c also improved in meta-analyses and in a placebo-controlled study in prediabetes 141861. The HOMA index also improved in several studies 14183761. Postprandial glucose improved in several studies 273661, and insulin levels improved in several studies 171861. Some of the findings come from combination products of berberine with milk thistle (silymarin), probiotics or other nutraceuticals; these results belong to the mixture 51516. Individual investigations found no confirmed difference in fasting glucose 175964, in HbA1c 1721 or in the HOMA index 17. Compared with metformin, HbA1c under barberry root extract did not differ 54. The strength of evidence is high, but the forms, doses and populations tested are inconsistent, and most studies lasted only a few months.

Further studies in this area: 18 21 22 27 28 29 30 35 36 37 54 56 57 59 61 63 64 65 77 79 85 86 94 95 96 98 103 107 112 113 114 115 117 123 125 126 128 129 131 133 134 135 136 137

Berberine and Blood Lipids: Human Studies

LDL cholesterol, total cholesterol and triglycerides fell more with berberine and barberry preparations than in the control groups in several meta-analyses 118202737. In a large placebo-controlled study, LDL cholesterol and apolipoprotein B fell more than with placebo 40. HDL cholesterol improved in some meta-analyses 3537, but remained unchanged in others 1820212759; in one study in rheumatoid arthritis, it fell with barberry extract compared with placebo 56. The forms tested were predominantly berberine salts and plant extracts from barberry bark, coptis or goldenseal, partly as a pure substance, partly in combination preparations with absorption aids; absorption differs between these forms. Individual randomized studies found no difference in blood lipids in NAFLD and with antipsychotics 5964. Combination preparations of berberine with milk thistle (silymarin) or with red yeast rice, policosanol and other additives also lowered blood lipids; however, this does not prove an effect of berberine alone 461516. The strength of evidence is high, but many studies do not state the exact form and dose, and the follow-up periods are mostly short.

Further studies in this area: 18 20 21 22 27 29 30 34 35 37 38 40 46 56 59 62 64 65 70 73 74 86 92 95 96 103 107 114 125 131 132 136 137

Berberine and Body Weight: Human Studies

Meta-analyses of randomized trials found a decrease in body weight, BMI and waist circumference with berberine compared with the control 2124; another confirmed this for BMI and waist circumference 27. In women with polycystic ovary syndrome, weight, BMI and waist circumference improved with berberine hydrochloride, metformin and myo-inositol; berberine showed the greater changes in comparison 65. The mixture of Berberis aristata and silymarin lowered BMI, waist circumference and abdominal fat in a placebo-controlled study 66. No difference in weight or BMI was found in a meta-analysis of barberry preparations in diabetes and in a study in fatty liver 1459. In schizophrenia under antipsychotics, weight and waist circumference increased more with barberry root extract than with placebo 64. The forms examined range from berberine hydrochloride through plant extracts from barberry bark and root to combination preparations with milk thistle, soy isoflavones or mulberry leaf extract; results on mixtures cannot be transferred to berberine alone. The findings apply to the respective form and preparation examined, and many meta-analyses gave no information on the form, purity or dose of berberine.

Further studies in this area: 40 54 56 59 64 65 79 86 109 110 119 125

Berberine and Polycystic Ovary Syndrome: Human Studies

In polycystic ovary syndrome, a randomized study compared berberine hydrochloride with metformin and myo-inositol: testosterone, free androgen index and SHBG improved in all groups, most markedly with berberine 65. An overview of systematic reviews found improvements in most endpoints with berberine in PCOS, but rated the quality of the reviews as predominantly low 29. The strength of evidence is moderate: there are two meta-analyses and one controlled study, but the form examined is inconsistent and partly not specified in detail. It remains open how the different berberine forms and their differing bioavailability affect the results.

Further studies in this area: 128

Berberine and Blood Pressure: Human Studies

Several meta-analyses found no difference from the control in either systolic or diastolic blood pressure 18192127. In a placebo-controlled study in fatty liver, the systolic pressure of pulse wave analysis fell with berberine compared with the baseline value; for vascular stiffness, no difference from placebo was found 55. A placebo-controlled study with barberry root extract in schizophrenia under antipsychotics also found no difference in blood pressure 64. The forms examined range from pure berberine substance through plant extracts from barberry bark or root to combination preparations with absorption aids. A mixed preparation of barberry extract with berberine, red yeast rice, milk thistle and guggul improved the vascular response (endothelial reactivity); this finding belongs to the mixture 53. The strength of evidence for an effect on blood pressure is unclear, and forms, preparations and comparison groups differ greatly.

Further studies in this area: 64 136

Berberine and Gut Microbiome: Human Studies

In a network meta-analysis of randomized trials on small intestinal bacterial overgrowth (SIBO), berberine alone achieved the highest rank for eradication of the overgrowth in uncomplicated SIBO 8. A systematic review of randomized trials describes an altered, not consistently favorable composition of the gut flora with berberine in diabetes, elevated blood lipids, intestinal polyps, mental illnesses and Parkinson's disease 22. Neither paper names the form examined; the underlying human studies are captured here only through these reviews, so the strength of evidence is unclear. Several further review articles describe a favorable influence on the gut microbiota by berberine, partly only as pure substance without a more detailed specification of form 107131, partly in mixtures with rifaximin, low-FODMAP diet, oregano oil, peppermint oil, garlic derivatives, vitamins and magnesium 105 or with herbal formulas, acupuncture, inulin, quinoa and linseed oil 113; these results of the mixtures are not evidence for berberine alone. What remains open are the exact form and dose examined, the transferability to individual patient groups and the value of berberine compared with established treatments.

Further studies in this area: 131

Berberine, Tolerability and Interactions: Human Studies

Randomized controlled trials on oral berberine 4055 and on an extract from barberry root (Berberis integerrima) compared with metformin 54 found no accumulation of side effects. Serious adverse events as well as kidney or liver toxicity also did not occur with oral berberine 61. A randomized controlled trial on the micellar formulation berberine LipoMicel showed no differences in liver and kidney values and in tolerability 62. For combination preparations of berberine with red yeast rice, policosanol, coenzyme Q10 and further components, randomized controlled trials found no differences in adverse events 4149, serious side effects 47 or discontinuations due to muscle pain 48. An overview of the Armolipid Plus mixture describes the tolerability as excellent 38. The strength of evidence is overall unclear: the controlled trials are mostly small and short, and several concern combination preparations. Possible interactions with blood pressure-lowering agents are addressed in an overview of several medicinal plants, including berberine 32. Thus, robust statements on rare or longer-term side effects, on interactions and on the comparison between the different forms such as berberine hydrochloride, berberine sulfate, berberine citrate, dihydroberberine or plant extracts remain open.

Further studies in this area: 61 62 69 72 76 80 81 83 85 90 92 94 95 99 104 107 109 115 130 132 137 138

Berberine: Further Outcomes in Studies

In a large placebo-controlled study in fatty liver and obesity, berberine lowered high-sensitivity C-reactive protein, but not liver fat content 40. A randomized study in fatty liver also found no difference in liver enzymes 59. In a randomized study in gum inflammation, plaque and gum bleeding improved under a mouth rinse with berberine hydrochloride, as well as under chlorhexidine and saline solution 50. In bacterial vaginosis, a vaginal gel made from barberry extract in a metronidazole base led in a randomized study to a better response than metronidazole gel alone 43. A combination product of berberine, curcumin, inositol, banaba and chromium picolinate also reduced inflammation markers in a placebo-controlled study in impaired blood sugar 42. Results of the mixtures cannot be transferred to berberine alone. The strength of evidence is high, but many studies do not name the exact form and dose, and the comparison conditions differ greatly.

Further studies in this area: 31 33 34 40 43 44 46 50 55 57 58 59 60 62 63 67 68 69 71 72 75 77 78 79 81 82 84 87 88 89 90 91 94 95 96 98 99 100 101 102 103 106 107 108 111 116 118 120 121 122 124 125 126 127 131 133

4. How Is Berberine Dosed? Preparation, Dose and Duration in Studies

Mainly berberine salts such as berberine hydrochloride, berberine sulfate and berberine citrate were tested, as well as plant extracts from barberry bark, coptis or goldenseal, sometimes as a pure substance, sometimes in combination preparations with absorption enhancers. Individual studies used dihydroberberine or a micellar formulation. Absorption differs between these forms, and many studies do not state the exact form and dose.

5. Is Berberine Safe? Side Effects in Studies

In a large placebo-controlled study, adverse events occurred with berberine about as often as with placebo 40, and another study described berberine as well tolerated 55. A barberry root extract led to no study discontinuation due to side effects compared with metformin 54. Serious adverse events as well as kidney or liver toxicity did not occur with oral berberine 61.

6. What Remains Open: Limits of the Evidence

• Many studies do not state the exact form, purity and dose of berberine tested.
• The follow-up periods are mostly short, so long-term effects and rare side effects remain open.
• Results for combination preparations cannot be transferred to berberine alone.
• Bioavailability differs greatly between the forms, which makes comparison of the studies difficult.
• Data on interactions with medications and on comparison of the forms with each other are still pending.

7. Bottom Line: What Is Established About Berberine

Berberine is a plant alkaloid from barberry and Coptis species, which in studies is mostly tested as a salt or plant extract. In people with elevated blood lipids, impaired blood sugar or overweight, several meta-analyses showed improvements in LDL cholesterol, triglycerides, fasting glucose, HbA1c and body weight 1141820242737. For blood pressure, however, several meta-analyses found no difference 192127.

In a large placebo-controlled study, adverse events under berberine did not occur more frequently than under placebo 40; two smaller studies observed no serious side effects 5561. However, the informative value is limited by the fact that the forms, doses and populations tested are inconsistent, many studies do not name the exact form, and the observation periods are short. Results of combination products of berberine with milk thistle (silymarin), red yeast rice or policosanol do not prove an effect of berberine alone 461516.