Does berberine help with weight loss?

In people with preexisting conditions that are related to metabolism (e.g., type II diabetes, PCOS, CVD, metabolic syndrome, NAFLD), berberine could potentially induce weight loss (as measured through BMI, body weight, waist circumference, and waist to hip ratio).^[1][2][3][4] However, the few studies in otherwise healthy participants did not echo these findings.^[5][4] Given the mechanisms by which berberine acts on metabolism, this might point to weight loss merely being a function of berberine’s regulation of metabolic factors, such as a decrease in the genes responsible for the body’s production of lipids and/or an increase in stored fatty tissue being used for energy.^[6] If so, then berberine may not be useful for weight loss in those without the matching genetic predisposition, since, for example, not all people who want to lose weight will meaningfully underexpress genes for fatty acid metabolism. While preclinical evidence on berberine for weight loss in those with metabolically related conditions is promising, the clinical evidence is still lacking in overall quality and consistent findings.^[7]