NHS Greater Glasgow & Clyde Area Drug and Therapeutics Committee
Greater Glasgow and Clyde Medicines
Medicines Update

Fast acting insulin aspart

Fast acting Insulin aspart (Fiasp®) has been accepted by the SMC and added to the Formulary. It is a modified formulation of insulin aspart with the property of more rapid absorption of insulin from subcutaneous injection site than standard insulin aspart (Novorapid®). The insulin absorption is stated to closely match the normal postprandial insulin release in non diabetics. 


Key messages

  • Fiasp and other insulins should be prescribed by brand
  • Fiasp, insulin aspart is not interchangeable with Novorapid® insulin aspart because of different absorption profiles.
  • Patients should be advised of non interchangeability and to routinely check labels prior to injecting.


The advantage of Fiasp is that it can be injected up to 20 minutes after starting a meal allowing for greater flexibility with meal times, meal size and insulin administration. There is some evidence that Fiasp is associated with lower postprandial glucose levels and improved glycaemic control compared to other rapid acting insulin.


Adverse effects in trials were no different to insulin aspart (Novorapid). 


In patients with type 1 diabetes, it is used in conjunction with longer acting basal insulin. As there is no price difference from Novorapid, the product is likely to become popular for patients on basal bolus insulin regimes. Though licensed for patients with Type 2 diabetes, demand is not anticipated as basal bolus regimes are rare for this patient group.


All insulin should be prescribed by brand on prescriptions and prescribing charts in all care settings to avoid dispensing and administration errors. This is particularly important with the introduction of concentrated and biosimilar insulins; the MHRA recommend brand prescribing for all biosimilars. The brand name should be included in all communications between the GP and secondary care.