Fiasp® is now available on the Pharmaceutical Benefits Scheme (PBS) for the treatment of diabetes mellitus. Fiasp® is a novel formulation of insulin aspart containing the excipients nicotinamide (vitamin B3) and arginine hydrochloride.

Human insulin molecules naturally self-associate to form hexamers that are too large to readily cross capillary membranes. The rate-limiting step for absorption and onset of action following subcutaneous injection is, therefore, the conversion of these hexamers into smaller units. Nicotinamide increases the rate of dissociation of insulin hexamers into dimers and monomers, resulting in faster absorption. Arginine is an amino acid that has been added to stabilise the formulation.

As nicotinamide and arginine hydrochloride are considered excipients, the generic name for Fiasp® is simply insulin aspart. It is important to note that this formulation is not interchangeable with NovoRapid®. In comparison to NovoRapid®, Fiasp® has an onset of action that is around five minutes faster and a glucose-lowering effect that is 74% greater during the first 30 minutes. Clinical trials demonstrate that this results in improved postprandial blood glucose control without increasing the overall risk of hypoglycaemia. The total and maximum glucose-lowering effect of Fiasp® is similar to that of NovoRapid®.

To avoid confusion, the Australian Commission on Safety and Quality in Healthcare recommend all insulin orders specify the full brand name of the product to be administered.


  1. Fiasp® (Insulin aspart) Australian approved product information. Baulkham Hills: Novo Nordisk. Approved July 2017.
  2. Heise T, Zijlstra E, Nosek L, Rikte T, Eng L, Haahr H. Pharmacological properties of faster‐acting insulin aspart vs insulin aspart in patients with type 1 diabetes receiving continuous subcutaneous insulin infusion: a randomized, double‐blind, crossover trial. Diabetes Obes Metab. 2017; 19(2): 208-15.
  3. Kildegaard J, Buckley ST, Nielsen RH, Povlsen GK, Seested T, Ribel U, et al. Elucidating the mechanism of absorption of fast-acting insulin aspart: the role of niacinamide. Pharm Res. 2019; 36(3): 49.

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