Solution for injection. The insulin aspart, or "NovoRapid", in NovoRapid 10mL vial is a rapid-acting insulin used to treat diabetes mellitus. Diabetes mellitus is a condition where your pancreas does not produce enough insulin to control your blood sugar (glucose) level. Extra insulin is therefore needed. NovoRapid lowers your blood sugar level after injection. When injected under your skin, NovoRapid has a faster onset of action than soluble human insulin. It takes effect within 10 to 20 minutes. Usually, the maximum effect will occur between 1-3 hours after injection and the effect may last for up to 5 hours.