Provider Briefing: The Insulin Aspart Supply Disruption

If your patients are reporting difficulty filling Insulin Aspart prescriptions, the data confirms what they're experiencing. Insulin Aspart remains on the ASHP drug shortage list as of early 2026, driven by a confluence of manufacturer discontinuations, biosimilar market transitions, and distribution challenges.

This briefing covers what you need to know to manage your patients through this period — from the timeline of events to prescribing alternatives and practice workflow adjustments.

Timeline: How We Got Here

Understanding the sequence of events helps frame the current situation:

• April 2024 — Fiasp FlexTouch 100 units/mL pen shortages begin, with Novo Nordisk citing manufacturing constraints. ASHP lists Insulin Aspart as in shortage.
• Late 2024 — Novo Nordisk announces plans to discontinue older NovoLog delivery forms and cut list prices by up to 75%, effective January 1, 2026. Unbranded biologic versions slated for discontinuation by end of 2025.
• February 2025 — FDA approves Merilog (insulin aspart-szjj, Sanofi), the first biosimilar to NovoLog.
• July 2025 — FDA approves Kirsty (insulin aspart-xjhz, Biocon/Viatris), the first interchangeable biosimilar to NovoLog.
• December 31, 2025 — Novo Nordisk discontinues NovoLog 10 mL vials, 3 mL PenFill cartridges, and 3 mL FlexPens.
• January 1, 2026 — Novo Nordisk's reduced pricing takes effect for Fiasp and remaining NovoLog products.

Prescribing Implications

Discontinued Forms

The following NovoLog presentations are no longer manufactured:

• 10 mL multiple-dose vials
• 3 mL FlexPen prefilled pens
• 3 mL PenFill cartridges

Prescriptions written for these forms will increasingly go unfilled. Update standing prescriptions to specify NovoLog FlexTouch, Fiasp FlexTouch, or a biosimilar to avoid pharmacy-level rejections.

Biosimilar Considerations

Kirsty (insulin aspart-xjhz) — As an interchangeable biosimilar, Kirsty can be substituted at the pharmacy level without prescriber intervention in most states. Patients may receive it automatically if their pharmacy stocks it. Clinical equivalence to NovoLog has been established through FDA-mandated switching studies.

Merilog (insulin aspart-szjj) — As a biosimilar without interchangeability designation, Merilog requires a prescription written specifically for it (or state laws that permit biosimilar substitution). Consider proactively writing prescriptions for Merilog if Kirsty is not available at your patients' pharmacies.

Therapeutic Alternatives

If Insulin Aspart is unavailable in any form, the following rapid-acting insulin analogs are clinically appropriate substitutes with comparable efficacy and safety profiles:

• Insulin Lispro (Humalog, Admelog, Lyumjev) — most widely available alternative; 1:1 dose conversion
• Insulin Glulisine (Apidra) — similar pharmacokinetic profile; available as vials and SoloStar pens

A 1:1 unit conversion is standard when switching between rapid-acting analogs. Recommend increased self-monitoring of blood glucose (SMBG) for 1-2 weeks post-switch. For patients on insulin pumps, verify pump compatibility with the new insulin formulation.

Current Availability Picture

Supply status as of early 2026:

• NovoLog FlexTouch pens — Available but intermittent constraints reported at high-volume pharmacies
• Fiasp FlexTouch and vials — Available; Novo Nordisk has prioritized Fiasp production
• Kirsty — Market launch underway; availability varies by region and pharmacy
• Merilog — Available at select pharmacies; distribution expanding
• Insulin Lispro products — No current shortage; widely available
• Insulin Glulisine (Apidra) — No current shortage; available at most pharmacies

Independent and specialty pharmacies tend to have better stock availability than large chain pharmacies during shortage periods.

Cost and Access Considerations

Affordability has improved significantly:

• Medicare Part D — $35/month insulin cap under the Inflation Reduction Act applies to all covered insulins, including Insulin Aspart and biosimilars
• Novo Nordisk price cuts — List prices reduced up to 75% as of January 2026 for Fiasp and remaining NovoLog products
• NovoCare Savings Card — Commercially insured patients may pay as low as $25 per prescription
• Patient Assistance Program (PAP) — Free insulin for uninsured patients meeting income criteria (≤400% FPL) through NovoCare
• Discount cards — GoodRx, SingleCare, and similar platforms offer generic insulin aspart for approximately $74-$100 per vial

For patients experiencing cost barriers, consider directing them to our savings guide: How to save money on Insulin Aspart in 2026.

Tools and Resources for Your Practice

Medfinder for Providers

Medfinder offers real-time pharmacy stock data that your staff can use to direct patients to pharmacies with Insulin Aspart in stock. This can reduce call-backs from patients unable to fill prescriptions and improve medication adherence during the shortage.

NovoCare Provider Resources

Novo Nordisk provides prescriber tools at novomedlink.com, including product availability updates, sample requests, and patient savings enrollment assistance.

ASHP Shortage Updates

Monitor the current shortage status at the ASHP Drug Shortages Resource Center for manufacturer-level supply updates.

Looking Ahead

The Insulin Aspart market is in transition. The convergence of manufacturer discontinuations, aggressive price reductions, and new biosimilar entrants is creating short-term disruption but should result in a more competitive, affordable landscape by late 2026.

Key developments to watch:

• Kirsty and Merilog distribution expansion — as supply scales up, pharmacy-level availability should improve throughout 2026
• Formulary updates — payers are incorporating biosimilars into preferred drug lists, which may affect which products your patients can access at lowest cost
• Additional biosimilar approvals — other manufacturers have insulin aspart biosimilars in their pipelines

Final Thoughts

The Insulin Aspart shortage requires proactive practice management. Review active prescriptions for discontinued forms, familiarize your team with biosimilar options, and direct patients to resources like Medfinder for Providers and NovoCare.

For a patient-facing version of this information, share our shortage update for patients. For guidance on helping patients find their medication, see our provider's guide to helping patients find Insulin Aspart.