The aim of this study is to evaluate the efficacy of a dietary supplementation with an extract from Cynara scolymus (Cs) on the glucose pattern in a group of patients with naïve impaired fasting glycaemia (IFG). A randomized, double-blind, placebo-controlled trial has been performed in 55 overweight subjects with IFG (fasting blood glucose [FBG]: 6.11 ± 0.56 mmol/l). These subjects were randomly assigned to supplement their diet with either an extract from Cs (600 mg/d) (26 subjects) or placebo (29 matched subjects) for 8 weeks. The decrease of FBG was the primary endpoint. The assessment of Homeostatic Metabolic Assessment (HOMA), glycosylated haemoglobin, A1c-Derived Average Glucose (ADAG), lipidic pattern and anthropometric parameters were the secondary endpoints. The within groups and percent changes from baseline were analyzed by the signed rank test. The comparison between groups was performed by Wilcoxon's two sample test. The supplemented group had significant decreases of: FBG (−9.6%), HOMA (−11.7%), glycosylated haemoglobin (−2.3%), ADAG (−3.1%) and lipidic pattern. The placebo group did not show any significant difference. Compared with the placebo, the supplemented group showed a significant difference in FBG, HOMA and lipidic pattern. These data demonstrate the efficacy of Cs extract on the reduction of glycometabolic parameters in overweight subjects with IFG. Copyright © 2013 John Wiley & Sons, Ltd.