Berberine benefits

How should the results of the meta-analyses be read?

Some of the findings below come from meta-analyses that also searched Chinese databases; the 2012 type 2 diabetes meta-analysis and the 2018 lipid meta-analysis reported low methodological quality in the included trials (random sequence generation, allocation concealment, blinding). ^{[4] [1]} A “significant decrease” therefore does not mean a clinically certain benefit. For each claim, who was studied and the quality are written separately.

Does berberine lower blood sugar in type 2 diabetes?

The meta-analysis by Guo and colleagues examined 46 RCTs comparing berberine, alone or together with standard treatments, with a control group. The mean difference for HbA1c was reported as −0.73 (95% CI −0.97 to −0.51); there were also decreases in fasting plasma glucose and 2-hour glucose, and in fasting insulin and HOMA-IR. ^[2] In another 2022 meta-analysis covering 37 trials and 3,048 patients, fasting glucose fell by 0.82 mmol/L, HbA1c by 0.63 percentage points and 2-hour glucose by 1.16 mmol/L. ^[3]

Limits: the 2012 meta-analysis pooling 14 RCTs (1,068 people) stated that methodological quality was generally low, samples small, the number of trials limited and the risk of bias unclear, and said that the evidence should be interpreted with caution. ^[1] The authors of the 2022 meta-analysis rated the certainty of the fasting glucose and HbA1c findings as “moderate” with GRADE (downgraded by one level for risk of bias). ^[3] Evidence grade: B (consistent direction across multiple meta-analyses; trial quality limited, certainty moderate at best).

Does berberine work as well as metformin?

No such conclusion can be drawn. In the 2012 meta-analysis, berberine did not show significantly better glycemic control when compared with oral antidiabetic drugs such as metformin, glipizide or rosiglitazone; a mild favorable effect of berberine on cholesterol was seen. When berberine was used together with the same drug, however, better glycemic control was found than with the drug alone. ^[1] A result of “not significantly better” does not show that it is “equivalent”; equivalence has not been separately proven. There are no data supporting that it replaces a drug in the treatment of a disease. Evidence grade: E (superiority not shown).

Does berberine lower cholesterol?

The 2018 meta-analysis by Ju and colleagues examined 2,147 participants in 16 RCTs. Total cholesterol fell by −0.47 mmol/L (95% CI −0.64 to −0.31), LDL cholesterol by −0.38 mmol/L (95% CI −0.53 to −0.22) and triglycerides by −0.28 mmol/L (95% CI −0.46 to −0.10); when used alone, HDL cholesterol rose by +0.08 mmol/L. The authors stated that, because of high clinical heterogeneity between trials and low methodological quality in most trials, the findings should be interpreted with caution, and that no serious adverse effects were reported. ^[4] Cardiovascular events (heart attack, stroke) were not examined as an outcome; only laboratory values were measured. Evidence grade: C.

Does berberine help with weight loss?

Asbaghi and colleagues reported in a meta-analysis pooling 12 RCTs that berberine lowered body weight by an average of 2.07 kg (95% CI −3.09 to −1.05), BMI by 0.47 kg/m², waist circumference by 1.08 cm and CRP by 0.42 mg/L; there was no significant effect on the liver enzymes ALT and AST. ^[5] In the meta-analysis in people with type 2 diabetes, the decrease in BMI had been reported as 1.07 kg/m². ^[2] The decreases are small. Evidence grade: C.

Does berberine work in PCOS?

In the 12-RCT meta-analysis by Xie and colleagues, the live birth rate with berberine was similar to placebo and metformin and lower compared with letrozole (RR 0.61; 95% CI 0.44–0.82); the authors concluded that there was no robust evidence that it improves live birth or other clinical outcomes. Compared with placebo and no treatment, berberine lowered total testosterone (8 RCTs, 577 people; mean difference −0.34) and the LH/FSH ratio (3 RCTs, 179 people; −0.44); compared with metformin, total cholesterol, waist circumference and waist-to-hip ratio were lower, and BMI did not differ. ^[6]

The 2024 meta-analysis covering 10 RCTs and 713 patients compared using berberine as adjuvant treatment together with Western medicine drugs against the drug alone: the ovulation rate (RR 1.41; 95% CI 1.26–1.60) and clinical pregnancy rate (RR 1.96; 95% CI 1.59–2.41) were higher; the authors stated that new trials are needed for a firm conclusion. ^[7] These two meta-analyses answer different questions (berberine alone or added to a drug), and the trials are small. Evidence grade: C for hormonal and metabolic indicators; E for live birth (no benefit shown).

Summary table