Provider Briefing: Semglee Supply in 2026

The intermittent shortage of Semglee (Insulin Glargine-yfgn) has created real challenges for clinicians managing patients with Type 1 and Type 2 diabetes. When patients can't fill their basal insulin, the clinical consequences — from hyperglycemic episodes to emergency department visits — fall squarely on the care team.

This briefing provides an up-to-date overview of the Semglee supply situation, prescribing considerations, alternative options, and tools to help your patients maintain access to their insulin.

Timeline: How We Got Here

Semglee, manufactured by Viatris, was approved by the FDA in 2020 and designated as the first interchangeable biosimilar insulin in 2021. This designation allows pharmacists to substitute Semglee for Lantus at the point of dispensing without prescriber intervention — a significant milestone for insulin access.

Key timeline events:

• 2021: Semglee gains interchangeable biosimilar status. Market adoption begins.
• 2022–2023: Demand surges as PBMs and insurance plans shift formularies toward lower-cost biosimilar insulins. Supply chain strains emerge.
• 2023: Eli Lilly, Novo Nordisk, and Sanofi announce major insulin price reductions, reshaping the competitive landscape and demand patterns.
• 2024: The Inflation Reduction Act's $35 Medicare insulin copay cap takes full effect, increasing utilization across all insulin products.
• 2025–2026: Semglee supply stabilizes in some regions but remains inconsistent in others, particularly for the pen formulation. Additional biosimilars (e.g., Rezvoglar) enter the market.

Prescribing Implications

The supply variability for Semglee has several practical implications for prescribers:

Interchangeability at the Pharmacy

Because Semglee is interchangeable with Lantus, pharmacists can substitute between the two without a new prescription. However, this only applies to Lantus ↔ Semglee. Substitution to Basaglar, Levemir, or Toujeo requires a new prescription.

If you want to ensure your patient receives a specific product, write "Dispense as Written" (DAW) on the prescription. Otherwise, the pharmacist may substitute based on availability and formulary position.

When to Proactively Prescribe Alternatives

Consider writing prescriptions for alternative basal insulins when:

• Your patient has reported difficulty filling Semglee on multiple occasions
• The patient's insurance formulary has shifted away from Semglee
• You're prescribing for a new patient and want to ensure first-fill success
• The patient requires a concentrated formulation (Toujeo 300 units/mL) for high-dose needs

Dose Conversion Considerations

When switching between insulin glargine products (Semglee, Lantus, Basaglar), the dose is typically unit-for-unit. When switching to different basal insulins:

• Levemir (Insulin Detemir): Start at the same unit dose, but be aware some patients may need twice-daily dosing. Monitor closely.
• Toujeo (Insulin Glargine 300 units/mL): When switching from 100 units/mL glargine, the Toujeo dose is typically the same number of units, but patients may need a 10–15% dose increase in the first few weeks due to different pharmacokinetics.

Current Availability Picture

As of early 2026:

• Semglee vials are generally more available than pens.
• Semglee pens remain intermittently constrained, with regional variation.
• Lantus is widely available but at a higher price point.
• Basaglar has good availability and competitive pricing (Eli Lilly's $35/month cap applies).
• Levemir availability varies; Novo Nordisk has been managing its insulin portfolio.
• Toujeo is generally available for patients needing concentrated insulin.
• Rezvoglar (insulin glargine-aglr, by Eli Lilly) is a newer biosimilar option with growing availability.

Cost and Access Considerations

Understanding the cost landscape helps you guide patients effectively:

• Semglee cash price: $125–$350 per pen pack or vial
• With Viatris savings card: As low as $0–$35 copay for commercially insured patients
• Medicare patients: $35/month cap under the Inflation Reduction Act
• Uninsured patients: Viatris Patient Assistance Program — free insulin for qualifying patients
• Basaglar: Eli Lilly's $35/month program applies regardless of insurance status

For patients struggling with cost, refer them to our resource: how to save money on Semglee. For provider-specific cost guidance, see our provider's guide to helping patients save on Semglee.

Tools and Resources for Your Practice

Medfinder for Providers

Medfinder offers a provider-facing tool that allows your staff to check real-time Semglee availability at pharmacies in your patients' areas. This can be integrated into your prescribing workflow to route prescriptions to pharmacies that currently have stock.

Recommended Workflow Adjustments

• E-prescribe to specific pharmacies: Before sending, have your staff verify stock via Medfinder or a quick phone call.
• Include alternatives on the prescription: Some EHR systems allow you to note an alternative medication if the primary is unavailable.
• Educate patients on the interchangeability: Many patients don't know that Semglee and Lantus are interchangeable at the pharmacy. A brief explanation can prevent unnecessary callbacks.
• Flag insulin patients for proactive outreach: Identify patients on Semglee in your panel and proactively address potential supply issues at their next visit or via patient portal messages.

FDA and Manufacturer Resources

• FDA Drug Shortage Database: accessdata.fda.gov/scripts/drugshortages
• ASHP Drug Shortage Resource Center: For the latest clinical guidance on managing insulin shortages
• Viatris Medical Information: For product-specific supply updates

Looking Ahead

The insulin biosimilar market is maturing. With more products entering the market (Rezvoglar, and potentially others), competition should continue to improve both pricing and availability over time. However, the complexity of biologic manufacturing means that supply disruptions will likely remain a periodic challenge.

Key trends to watch:

• Additional insulin biosimilar approvals and launches
• PBM formulary decisions for 2026–2027 plan years
• Potential expansion of the $35 copay cap to commercial insurance
• Manufacturing capacity investments by Viatris and other biosimilar manufacturers

Final Thoughts

The Semglee shortage has been a disruptive force in diabetes care, but the tools and alternatives exist to keep patients safe and well-managed. By staying informed about supply trends, proactively prescribing alternatives when needed, and leveraging tools like Medfinder for Providers, you can minimize the impact on your patients.

For the patient-facing version of this update, share our Semglee shortage update for patients with your panel. And for a practical guide to helping patients locate their insulin, see how to help your patients find Semglee in stock.