Berberine has attracted serious attention from researchers over the past two decades, and for good reason. This bright yellow alkaloid, extracted from plants like goldenseal, barberry, and Chinese goldthread (Coptis chinensis), produces effects that rival some pharmaceutical drugs in clinical trials. That’s a strong statement for a supplement, and the evidence backing it is surprisingly robust.

For thousands of years, berberine has been used in Traditional Chinese Medicine and Ayurvedic practice, primarily for gastrointestinal complaints. Modern research has expanded our understanding considerably, revealing mechanisms that affect blood sugar regulation, cholesterol metabolism, and inflammatory pathways throughout the body.

What makes berberine unusual among supplements is its ability to activate an enzyme called AMP-activated protein kinase (AMPK), sometimes called the body’s “metabolic master switch.” This same pathway is targeted by metformin, one of the most widely prescribed diabetes medications globally 1.

What is berberine?

Berberine is an isoquinoline alkaloid found in the roots, stems, and bark of several medicinal plants. The name comes from the genus Berberis (barberries), though it’s found in multiple plant families including Ranunculaceae (buttercups) and Rutaceae (citrus family). The compound itself is bright yellow and has a distinctly bitter taste.

Traditionally, berberine-containing plants have been used to treat diarrhoea, dysentery, and various infections. In fact, berberine remains an over-the-counter treatment for gastrointestinal issues in some Asian countries. Modern extraction and standardisation have made it available as a concentrated supplement.

The compound has remarkably broad pharmacological activity. Beyond metabolic effects, research has explored its potential in treating cardiovascular disease, certain cancers, neurological conditions, and bacterial infections. However, not all these applications have equal evidence behind them.

Evidence-based benefits of berberine

1. Blood sugar management in type 2 diabetes

This is where berberine has the strongest evidence. Multiple randomised controlled trials have compared berberine head-to-head with metformin and found comparable blood sugar-lowering effects 2.

A meta-analysis published in the Journal of Ethnopharmacology examined 14 randomised trials involving over 1,000 patients with type 2 diabetes. Berberine significantly reduced fasting blood glucose, postprandial blood glucose, and HbA1c (a marker of long-term blood sugar control) compared to placebo. When combined with standard diabetes medications, berberine produced additional reductions 3.

The mechanism appears to work through multiple pathways: berberine increases insulin sensitivity, promotes glucose uptake into cells, and slows carbohydrate breakdown in the gut. This multi-pronged approach may explain its effectiveness.

My take: The diabetes evidence is genuinely impressive for a supplement. However, berberine isn’t a replacement for proper medical care. If you’re managing diabetes, work with your doctor—berberine can interact with diabetes medications and cause dangerous hypoglycaemia if doses aren’t adjusted.

2. Cholesterol reduction

Berberine’s effect on blood lipids has been demonstrated in numerous clinical trials. A systematic review and meta-analysis examining 16 trials found that berberine significantly reduced total cholesterol, LDL (“bad”) cholesterol, and triglycerides, whilst modestly increasing HDL (“good”) cholesterol 4.

The doses used in these studies ranged from 600mg to 1,500mg daily, with treatment periods spanning 2 to 24 months. Importantly, adverse event rates were similar between berberine and control groups, suggesting reasonable tolerability.

Berberine appears to lower cholesterol through different mechanisms than statin drugs. It increases LDL receptor expression on liver cells (helping clear cholesterol from the blood) and may also reduce cholesterol absorption from the gut.

Worth noting: Berberine might be worth considering if you can’t tolerate statins, though the cholesterol-lowering effect is generally more modest. See our article on red yeast rice for another natural approach to cholesterol management.

3. Non-alcoholic fatty liver disease (NAFLD)

Non-alcoholic fatty liver affects roughly 25% of adults globally and is closely linked to obesity and insulin resistance. Given berberine’s metabolic effects, researchers have investigated its potential here.

A meta-analysis of 6 randomised controlled trials involving 501 patients with NAFLD found that berberine (300-500mg daily for 12-16 weeks) improved liver enzyme levels (ALT), blood sugar control, and lipid profiles 5.

The evidence is promising but limited. Sample sizes were small, treatment durations were short, and study quality varied. Lifestyle changes (diet and exercise) remain the cornerstone of NAFLD management, though berberine might offer additional support. For more on liver-supportive supplements, see our guide to health foods for fatty liver.

The catch: Don’t expect dramatic results from berberine alone. Fatty liver requires comprehensive lifestyle intervention.

4. Weight management

Several trials have examined berberine’s effects on body weight and composition. A meta-analysis of 9 randomised controlled trials found that berberine supplementation reduced BMI and waist circumference, though absolute weight loss wasn’t always significant 6.

Subgroup analysis revealed the best results in participants with baseline BMI over 30, in women, with treatment lasting more than 12 weeks, and at daily doses exceeding 1 gram.

The weight loss mechanism likely relates to berberine’s effects on metabolism, insulin sensitivity, and possibly gut bacteria. However, the magnitude of weight loss is modest—don’t expect dramatic changes without dietary and exercise modifications.

Reality check: Berberine isn’t a weight loss miracle. Any benefit is likely small and works best alongside proper diet and exercise.

5. Polycystic ovary syndrome (PCOS)

PCOS is the most common endocrine disorder in women of reproductive age, characterised by hormonal imbalances, insulin resistance, and ovarian cysts. Given the metabolic overlap with type 2 diabetes, berberine has been studied as a potential treatment.

A systematic review of 9 randomised controlled trials in women with PCOS and insulin resistance found that berberine was comparable to metformin for improving insulin sensitivity, glucose metabolism, and reproductive hormone levels 7.

Interestingly, when berberine was combined with the standard PCOS medication cyproterone acetate, results were better than medication alone.

My assessment: For women with PCOS who experience gastrointestinal side effects from metformin (which is common), berberine might be a reasonable alternative to discuss with their doctor.

6. Colorectal adenoma prevention

Colorectal adenomas are benign polyps that can progress to colorectal cancer. Early removal through polypectomy reduces cancer risk by 76-90% 8, but recurrence remains a concern.

A meta-analysis of 3 randomised controlled trials involving 1,076 adults with a history of colorectal adenoma found that berberine supplementation reduced the recurrence rate 9.

This is intriguing preliminary evidence. Berberine may offer a chemoprevention option for people at elevated colorectal cancer risk, though more research is needed to confirm effectiveness and determine optimal dosing.

A word of caution: This doesn’t replace colonoscopy screening or polyp removal. It’s a potential adjunct therapy, not a primary prevention strategy.

7. Helicobacter pylori eradication

H. pylori infection affects nearly half the world’s population and is strongly linked to gastric ulcers and stomach cancer. Standard treatment involves “triple therapy”—two antibiotics plus a proton pump inhibitor—but eradication rates have declined due to antibiotic resistance.

A meta-analysis of 13 randomised controlled trials involving 2,048 patients found that adding berberine to triple therapy improved H. pylori eradication rates whilst reducing side effects, particularly nausea and diarrhoea 10.

In practice: If you’re being treated for H. pylori, berberine might improve your chances of successful eradication. The reduced side effects are a notable bonus given how unpleasant triple therapy can be.

Side effects of berberine

For most healthy adults using appropriate doses, berberine is generally well-tolerated. However, side effects do occur, particularly gastrointestinal complaints:

Digestive upset: Abdominal cramps, diarrhoea, flatulence, constipation, and stomach pain are the most common complaints, typically occurring at treatment initiation
Blood pressure changes: Berberine can lower blood pressure, which may cause dizziness in some individuals
Hypoglycaemia: When combined with diabetes medications, berberine may cause blood sugar to drop too low
Flu-like symptoms: Some users report general malaise
Cardiac effects: At high doses, berberine has been associated with cardiac effects in rare cases 11

Starting with a lower dose and gradually increasing can help minimise gastrointestinal side effects. Taking berberine with meals also improves tolerability.

Five important contraindications

1. Pregnancy and breastfeeding

Berberine should not be used during pregnancy or whilst breastfeeding. It can cross the placenta and may cause kernicterus (a type of brain damage) in newborns with jaundice. This is a serious concern, not a theoretical one.

2. Blood sugar-lowering medications

If you take metformin, insulin, or other diabetes medications, adding berberine without medical supervision could cause dangerous hypoglycaemia. Blood sugar levels need to be monitored closely, and medication doses may need adjustment.

3. Blood pressure medications

Berberine’s blood pressure-lowering effect can compound with antihypertensive medications, potentially causing hypotension (dangerously low blood pressure).

4. Cyclosporine

Berberine slows the metabolism of cyclosporine (an immunosuppressant used after organ transplants), increasing blood levels and the risk of toxicity. This combination should be avoided.

5. Cytochrome P450 interactions

Berberine inhibits several cytochrome P450 enzymes that metabolise many common medications. This can increase drug levels and side effects. Medications with potential interactions include:

Antibiotics: Clarithromycin, erythromycin
Antiarrhythmics: Quinidine
Benzodiazepines: Alprazolam, clonazepam
Calcium channel blockers: Amlodipine, diltiazem, nifedipine, verapamil
Statins: Atorvastatin, lovastatin, simvastatin
HIV medications: Atazanavir, darunavir, indinavir
Immunosuppressants: Cyclosporine, tacrolimus
Hormones: Oestradiol, testosterone

If you take any prescription medications, consult your doctor or pharmacist before starting berberine.

Dosage and how to take berberine

Clinical trials have typically used doses of 900-1,500mg daily, divided into two or three doses. Berberine has a short half-life (about 5 hours), so splitting the dose maintains more stable blood levels.

A common approach is 500mg three times daily, taken with meals or shortly after eating. Starting with a lower dose (such as 500mg once daily) and gradually increasing helps minimise digestive side effects.

For blood sugar management, timing doses with meals makes physiological sense, as berberine can help moderate postprandial glucose spikes.

Should you try berberine?

Berberine is one of the more evidence-backed supplements available, particularly for metabolic conditions like type 2 diabetes and high cholesterol. The research quality is higher than many supplements receive, with numerous randomised controlled trials and meta-analyses.

That said, it’s not without limitations. Effects are generally modest, gastrointestinal side effects are common, and drug interactions are numerous. For people managing diabetes or taking multiple medications, medical supervision is essential.

If you’re interested in natural approaches to blood sugar or cholesterol management, berberine deserves consideration—but as part of a comprehensive approach that includes diet, exercise, and appropriate medical care. See also our articles on chromium, fenugreek, and bitter melon for other supplements with blood sugar-related evidence, and our guide to diabetic bladder dysfunction for information on how diabetes affects urinary health.

References

Yin J, Xing H, Ye J. Efficacy of berberine in patients with type 2 diabetes mellitus. Metabolism. 2008;57(5):712-717. PubMed
Dong H, Wang N, Zhao L, Lu F. Berberine in the treatment of type 2 diabetes mellitus: a systemic review and meta-analysis. Evid Based Complement Alternat Med. 2012;2012:591654. PubMed
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
Asbaghi O, Ghanbari N, Shekari M, et al. The effect of berberine supplementation on obesity parameters, inflammation and liver function enzymes: A systematic review and meta-analysis of randomized controlled trials. Clin Nutr ESPEN. 2020;38:43-49. PubMed
Zhu X, Bian H, Gao X. The Potential Mechanisms of Berberine in the Treatment of Nonalcoholic Fatty Liver Disease. Molecules. 2016;21(10):1336. PMC
Ilyas Z, Perna S, Al-Thawadi S, et al. The effect of Berberine on weight loss in order to prevent obesity: A systematic review. Biomed Pharmacother. 2020;127:110137. PubMed
Li MF, Zhou XM, Li XL. The Effect of Berberine on Polycystic Ovary Syndrome Patients with Insulin Resistance (PCOS-IR): A Meta-Analysis and Systematic Review. Evid Based Complement Alternat Med. 2018;2018:2532935. PMC
Winawer SJ, Zauber AG, Ho MN, et al. Prevention of colorectal cancer by colonoscopic polypectomy. N Engl J Med. 1993;329(27):1977-1981. PubMed
Chen YX, Gao QY, Zou TH, et al. Berberine versus placebo for the prevention of recurrence of colorectal adenoma: a multicentre, double-blinded, randomised controlled study. Lancet Gastroenterol Hepatol. 2020;5(3):267-275. PubMed
Yang Y, Ye Y, Chen X, et al. Berberine combined with triple therapy versus triple therapy for Helicobacter pylori eradication: A meta-analysis of randomized controlled trials. Medicine (Baltimore). 2018;97(46):e13186. PMC
Neag MA, Mocan A, Echeverría J, et al. Berberine: Botanical Occurrence, Traditional Uses, Extraction Methods, and Relevance in Cardiovascular, Metabolic, Hepatic, and Renal Disorders. Front Pharmacol. 2018;9:557. PubMed