In vitro and animal studies suggest that silybin may modulate glucose uptake in adipocytes (fat cells), and may inhibit gluconeogenesis (i.e., glucose biosynthesis) and glycogenolysis (i.e., glycogen breakdown) in a dose-dependent manner.[1]
In one randomized controlled trial (RCT) in people with type 2 diabetes, 200 mg of silymarin taken three times a day before meals resulted in a significant reduction in blood glucose and glycated hemoglobin (HbA1c) levels, compared to placebo.[2]
In a 1993 RCT in people with diabetes caused by liver cirrhosis, a daily intake of 600 mg of silymarin (divided into three doses) for 6 months was associated with a significant reduction in fasting glucose and mean daily glucose levels from the second month of treatment onwards, without any increase in episodes of hypoglycemia. Moreover, the treated patients experienced a significant decrease in mean insulin need during treatment, accompanied by a substantial drop in fasting insulinemia.[3]