Phentermine 15 mg is a medication that is generally advised to the people suffering from obesity to lose weight along with a better diet and proper regular physical exercise. It is also prescribed to the patients after complete medical examinations that are experiencing obesity due to diabetes, hypertension and other medical factors. The medication reductil accommodates sibutramine, which is an active ingredient which works by increasing the level of the two chemicals serotonin and noradrenaline found in the brain that control and regulate appetite.