US FDA Approves Garzulys — Third Insulin Aspart Biosimilar Enters the Market

The US FDA has approved Garzulys (insulin aspart-fsan), a rapid-acting insulin biosimilar to Novo Nordisk's NovoLog, developed by Meitheal Pharmaceuticals as U.S. regulatory agent under license from BLA holder Emerge Bioscience. The approval covers both adult and pediatric patients with diabetes mellitus, for glycemic control, and is approved in both subcutaneous and intravenous formulations.

Why it matters:
Garzulys becomes the third insulin aspart biosimilar to reach the U.S. market referencing NovoLog, following Merilog (approved February 2025) and Kirsty (approved July 2025). For clinicians, this continues a meaningful shift: rapid-acting insulin, once dominated by a handful of branded originators, now has a genuinely competitive biosimilar landscape — a trend with real potential to ease cost pressure for patients who rely on mealtime insulin.

Important clinical note: Garzulys has not received an FDA interchangeability designation. That distinction matters at the pharmacy counter — without it, a pharmacist generally cannot automatically substitute Garzulys for NovoLog without a prescriber's explicit authorization, unlike an interchangeable biosimilar. With three similarly-named insulin aspart biosimilars now on the market (Garzulys, Kirsty, Merilog), look-alike/sound-alike confusion at prescribing and dispensing is a real and growing risk worth being deliberate about.

Bottom line for practice: if you're prescribing rapid-acting insulin, it's worth confirming which specific aspart product a patient is actually using — brand name, biosimilar name, and manufacturer — rather than assuming "insulin aspart" is interchangeable shorthand across all three products on shelves today.