Insulin aspart

also known as: NovoLog, NovoRapid, Fiasp, Kirsty

Novo Nordisk's rapid-acting insulin analog (NovoLog / NovoRapid, approved 2000) — the B28 proline → aspartate substitution destabilizes hexamer formation, and the ultra-rapid Fiasp formulation (2017) adds niacinamide and L-arginine for even faster absorption.

A rapid-acting recombinant human insulin analog (NovoLog in the US, NovoRapid internationally, Novo Nordisk, FDA-approved 2000) with proline at B28 replaced by aspartic acid to disrupt hexamer self-association; Fiasp (faster aspart, approved 2017) is the same molecule with niacinamide and L-arginine added to further accelerate subcutaneous absorption for tighter postprandial glucose control.

Mechanism of action

Insulin receptor agonism. The aspartate substitution at B28 introduces a negative charge that prevents hexamer self-association, allowing rapid dissociation into monomers after SC injection and faster absorption than regular human insulin. Fiasp adds niacinamide (to enhance early absorption via local vasodilation) and L-arginine (for formulation stability).

Primary uses

Type 1 diabetes mellitus (mealtime bolus)
Type 2 diabetes mellitus requiring prandial insulin
Insulin pump therapy (CSII)

Typical dosing

with meals (subcutaneous or IV)

Fully individualized dosing as with all mealtime insulins.

Regulatory status

FDA-approved 2000 as NovoLog (Novo Nordisk). Fiasp (faster aspart) approved 2017. Kirsty (biosimilar) approved more recently.

References

[fda-pi] FDA. NovoLog (insulin aspart) prescribing information. Novo Nordisk, updated 2024.
[fda-pi] FDA. Fiasp (insulin aspart faster-acting) prescribing information. Novo Nordisk, 2017.
[pubmed] Brange J, et al. "Monomeric insulins obtained by protein engineering and their medical implications." Nature, 1988;333:679-682.

Related peptides

Insulin lispro

The first FDA-approved rapid-acting insulin analog (Humalog, Lilly, 1996) — the B28–B29 position swap prevents hexamer self-association, producing faster subcutaneous absorption than regular human insulin.

Insulin glulisine

Sanofi's rapid-acting insulin analog (Apidra, 2004) — the third rapid-acting analog approved, differentiated by being zinc-free in formulation, which gives it slightly faster monomeric onset than lispro or aspart.

Regular human insulin

The original recombinant human insulin (Humulin R, 1982) — unmodified native sequence, short-acting kinetics driven by hexamer self-association; U-500 concentration for severely insulin-resistant patients.

Disclaimer

This entry is for educational purposes only and does not constitute medical advice. Dosing information reflects published regulatory or research data and is not a recommendation. Many compounds described here are not approved for human use in the United States. Consult a licensed medical professional before considering any peptide therapy.