The United States is not experiencing an across-the-board insulin shortage, but several specific insulin products have been discontinued or are harder to find than they were a few years ago. The disruptions are concentrated in certain formulations, particularly pen-style delivery devices and older insulin types, rather than affecting every product on pharmacy shelves. If you or someone you know uses insulin, whether you’re affected depends largely on which brand and delivery method you rely on.
Which Insulin Products Are Affected
The biggest changes have come from Novo Nordisk, which permanently discontinued all formulations of Levemir, a long-acting insulin that millions of people relied on. Supply disruptions for the Levemir FlexPen began in January 2024, with the pen fully discontinued by April 2024. The Levemir vial followed, discontinued at the end of December 2024. If Levemir was part of your routine, it is no longer available once existing pharmacy stock runs out.
Novo Nordisk is also winding down production of its human insulin pens globally, transitioning human insulin to vial-only availability. That means people who preferred the convenience of a prefilled pen for older-generation human insulin will need to switch to vials and syringes or move to a different product.
Eli Lilly discontinued Humalog 3 mL vials in early 2024 but continues to supply the larger 10 mL vials of both Humalog and its generic equivalent, insulin lispro. Sanofi’s products have remained more stable. Lantus vials, Lantus SoloStar pens, and both sizes of Toujeo prefilled pens are all currently listed as available.
Why Manufacturers Are Pulling Back
The primary driver behind these disruptions is not a raw materials problem or a sudden spike in demand for insulin itself. Instead, manufacturers are reallocating production capacity toward GLP-1 medications, the class of drugs that includes treatments for type 2 diabetes and weight loss. Demand for these newer drugs has been enormous, and the companies that make insulin are the same ones racing to keep up with GLP-1 orders.
Novo Nordisk has been explicit about this tradeoff. A company spokesperson cited “capacity constraints” as the reason for transitioning human insulin pens to vials only, acknowledging that manufacturing resources are being redirected toward GLP-1 production. When a company that controls a large share of the insulin market shifts its priorities, the ripple effects are immediate.
The structure of the insulin market makes it especially vulnerable to these kinds of decisions. Three companies, Eli Lilly, Novo Nordisk, and Sanofi, control 96% of the global insulin market by volume and 99% by value. Biosimilar competitors exist but have struggled to gain significant market share. When one of the three major producers discontinues a product or exits a segment, there are very few alternative suppliers to fill the gap.
What This Means at the Pharmacy
For most people who use rapid-acting or long-acting analog insulins in standard vials or modern pen devices, supply has remained relatively steady. The products most likely to be difficult to find are discontinued formulations like Levemir, Humalog 3 mL vials, and human insulin pens from Novo Nordisk. If your pharmacy tells you a product is unavailable, it may not be a temporary backorder. It may be gone permanently.
Switching insulin products is not as simple as picking a different brand off the shelf. Different insulins have different onset times, peak activity windows, and durations. A change from Levemir to another long-acting insulin like Lantus or Toujeo, for example, may require dose adjustments and closer blood sugar monitoring during the transition. Your prescriber will need to write a new prescription, and your insurance formulary may cover the alternative differently.
Hospitals and health systems have formal shortage management protocols. Pharmacy teams track supply disruptions, identify alternative therapies, and coordinate switches across their patient populations. At the retail level, the process is less structured. You may find out about a discontinuation only when you show up to refill a prescription and your pharmacist tells you the product is no longer manufactured.
Insulin Rationing Persists
Supply disruptions are compounding a problem that predates these shortages. Research published in the Journal of General Internal Medicine compared insulin rationing behavior in 2017 and 2024 and found that people continue to skip doses, use less than prescribed, or delay refills to stretch their supply. Even with recent policy changes aimed at capping out-of-pocket insulin costs, rationing persists. When a familiar product disappears and the replacement costs more or requires prior authorization from an insurer, the risk of rationing increases.
The $35 monthly copay cap that took effect for Medicare patients in 2023 helped reduce costs for that population, but it does not apply to everyone. People with private insurance, high-deductible plans, or no insurance at all may still face significant expenses, especially if a shortage forces them onto a brand-name product that their plan covers less generously.
How Long Disruptions May Last
There is no single resolution date for insulin supply issues because the disruptions stem from deliberate business decisions rather than temporary manufacturing problems. Novo Nordisk’s global wind-down of human insulin pen production is expected to continue through 2026, with timelines varying by country. The European Medicines Agency lists an expected resolution date of end of 2026 for human insulin supply adjustments in Europe, meaning the transition away from certain formulations will stretch over the next year or more.
In the U.S., the products that have already been discontinued are not coming back. The question going forward is whether additional formulations will be cut as manufacturers continue shifting capacity toward GLP-1 drugs. If you currently use an insulin product that remains available, there is no immediate cause for alarm, but it is worth knowing which manufacturer makes your insulin and watching for announcements about changes to their product lineup. Your pharmacist is often the first to know when a product’s availability status changes.