NovoRapid Penfill is a rapid-acting insulin analogue containing insulin aspart, designed to manage blood glucose levels in individuals with diabetes mellitus. Each 3 mL cartridge delivers 300 units of insulin aspart (100 IU/mL). It starts to lower blood sugar within 10–20 minutes after subcutaneous injection, peaks in 1–3 hours, and lasts for 3–5 hours. Typically administered at the start of a meal or within 20 minutes after beginning to eat, NovoRapid Penfill is often used in combination with longer-acting insulins. It is compatible with Novo Nordisk insulin delivery systems like the NovoPen® and is available by prescription.