Insulin aspart. Molecular model of the drug insulin aspart (C256.H381.N65.O79.S6). This drug, sold under the brand name Novolog, is a rapid-acting human insulin analogue used to lower blood glucose. It is used to improve glycaemic control in adults and children with diabetes mellitus. Atoms are represented as spheres and are colour-coded: carbon (grey), hydrogen (white), nitrogen (blue), oxygen (red) and sulfur (yellow).