Insulin, Regular, Human Shortage: What Providers and Prescribers Need to Know in 2026

For primary care physicians, endocrinologists, and diabetes educators managing patients on regular human insulin, 2026 brings a set of critical product changes that require proactive communication and prescription updates. This guide summarizes the current formulation status, clinical implications of switching, and how to counsel your patients effectively.

Current Product Status: What Has Changed

Eli Lilly has made the following commercial decisions affecting Humulin R:

Humulin R 100 units/mL, 3 mL multi-dose vial: Permanently discontinued. ASHP tracking began January 2024.

Humulin R U-500, 20 mL vial: Discontinued by Lilly in late 2025.

Humulin R 100 units/mL, 10 mL vial: Available. Primary Humulin R formulation.

Humulin R U-500 KwikPen: Available. This is now the only U-500 delivery option.

Novolin R (Novo Nordisk), 10 mL vial + FlexPen: Available. Not affected by Lilly's changes.

Clinical Considerations: Patients on U-100 Regular Insulin

For patients using U-100 regular insulin (most common), the transition from a 3 mL vial to a 10 mL vial or Novolin R is clinically straightforward:

No dose adjustment is required. Concentration is identical (100 units/mL).

The same syringes are used. Patients using U-100 syringes for Humulin R can use them for Novolin R.

Counsel patients on updated storage expiration. Opened 10 mL Humulin R vials should be used within 28 days at room temperature; opened Novolin R vials within 42 days.

Clinical Considerations: Patients on U-500 Regular Insulin

Patients on Humulin R U-500 vials must transition to the U-500 KwikPen. Key clinical considerations:

The KwikPen uses a different delivery mechanism than syringes used with vials. Patient education on pen use is essential.

The Humulin R U-500 KwikPen delivers doses in 5-unit increments. Patients previously drawing up variable doses in a syringe need specific counseling.

Update prescriptions to specify the KwikPen presentation. Avoid ambiguous prescription language that might confuse pharmacists.

When to Consider Transitioning to a Rapid-Acting Analog

The current disruption may be a good opportunity to reassess whether patients on regular human insulin are the best-served by their current regimen. Rapid-acting analogs (insulin lispro, aspart, glulisine) offer:

Faster onset (10–15 minutes vs. 30–60 minutes) for greater flexibility with meals

Lower post-prandial glucose variability in many patients

Lower cost now available: generic insulin lispro from Lilly at ~$25/vial; $35/month maximum via Insulin Value Program

That said, some patients have been stable on regular insulin for decades and may not benefit from the switch. Cost, patient preference, and glycemic patterns should guide the decision.

Key Formulary and Insurance Considerations

Medicare Part D: $35/month per insulin product cap under the Inflation Reduction Act. Applies to all covered insulins including Humulin R and Novolin R.

Lilly Insulin Value Program: Caps Humulin R at $35/month, with or without insurance. Contact: insulinaffordability.com or 1-833-808-1234.

Novo Nordisk My Insulin Rx: $35 for up to 3 vials or 2 pen packs of Novolin R. Does not require insurance.

Novo Nordisk Patient Assistance Program: Free medication for qualifying uninsured/low-income patients.

Communicating With Patients About This Transition

Proactive communication is key. Consider:

Sending a notice to all patients currently prescribed Humulin R 3 mL vials

Updating prescriptions proactively to specify available formulations

Directing patients to medfinder if they're struggling to locate their formulation at a nearby pharmacy

Prescribers: medfinder for providers offers a structured way to help your patients find in-stock insulin without placing the burden on your staff.

See also our provider-specific guide: How to Help Your Patients Find Insulin, Regular, Human in Stock.