The present study aims to evaluate physicochemical characteristics and the effectiveness of pharmacological effects of a Glimepiride generic product, compared to its originator Amarel a sulfonylurea used to treat type 2 diabetes mellitus. Two doses 2 and 4 mg per day were tested on male albino rats diabetics with alloxan. Body weights, glycemia, HbA1c, lipid profile, total protein, the activity of certain enzymes and some renal parameters were determined. The results showed that physicochemical characteristics are compliant with standards of the American Pharmacopeia compared with the used reference substance. However, the biological study revealed a dosedependent effect of Amarel on body weights, blood glucose and lipid profile of rats during and after the treatment, which was not obtained with the generic. Total protein and enzymes activities of serum transaminases, amylase and lipase were almost identical in groups treated with 4 mg of originator and generic. The 2 mg dose has not exerted the expected therapeutic effect. These results show that the studied generic exhibited less efficacy than the originator despite compliance of physicochemical characteristics. A supply of the generic with the aqueous extract of a local medicinal plant (Zygophyllum cornutum) was performed where the results of measuring blood glucose before and after sacrifice of rats were similar to those of healthy controls. No significant difference was recorded for renal parameters in all treated groups.