A 12-week randomized, double-blind controlled trial conducted in Hong Kong investigated the effect of berberine supplementation on cardiovascular disease (CVD) risk factors and testosterone in men. Berberine, an isoquinoline plant alkaloid, possesses strong anti-lipidemic, anti-inflammatory, and cardioprotective properties, with previous literature suggesting its use for managing symptoms of CVD. Authors recruited male volunteers aged 20 to 65 years with hyperlipidemia, defined by (1) triglyceride levels > 150 mg / dl, (2) total cholesterol > 200 mg / dl, and/or (3) LDL cholesterol > 100 mg /dL. Participants were randomly allocated to receive the intervention – purified 500 mg berberine tablets – or a similar placebo material, both supplemented orally twice daily for the study duration. Primary outcomes measured included: lipids, triglycerides, HDL cholesterol, thromboxane A2, systolic and diastolic blood pressure, and serum testosterone, with body mass index (BMI) and waist-hip ratio (WHR) included as secondary outcomes. Researchers used an analysis of variance and generalized estimating equation (GEE) to assess differences between the berberine (n = 40) and placebo (n = 40) group at weeks 8 and 12. Study results were consistent with current evidence, showing a statistically significant lowering effect of berberine on total cholesterol (p = 0.0001) and perhaps also LDL cholesterol (p = 0.03). Other key findings include a null effect of berberine on thromboxane A2 and a possible increase in testosterone in men (p = 0.01). This study suggests that berberine might safely lower cholesterol and could influence specific sex hormones in men.