Insulin, Human Isophane (NPH) Shortage: What Providers and Prescribers Need to Know in 2026

This briefing is intended for physicians, nurse practitioners, physician assistants, and other prescribers managing patients on insulin, human isophane (NPH insulin). It covers the current supply landscape in 2026, clinical considerations for alternative insulins, and recommendations for proactive patient communication.

Current Supply Status (2026): What Prescribers Need to Know

As of 2026, standalone insulin isophane human (NPH) products — Humulin N and Novolin N — are not on the FDA Drug Shortages list. National supply from both Eli Lilly and Novo Nordisk has been maintained. However, prescribers should be aware of the following:

• ASHP 2024 shortage bulletin: ASHP issued a shortage bulletin in May 2024 for combination insulin NPH and regular human products (e.g., Humulin 70/30, Novolin 70/30). Standalone NPH was not included, but availability was impacted in some regions.
• Localized stockouts: Pharmacy-level stockouts of Humulin N or Novolin N, particularly pen formulations, have been reported across multiple regions. These are driven by demand-supply mismatches at the distributor level rather than manufacturing failures.
• Increased NPH demand from analog shortages: Shortages of glargine biosimilars (Semglee discontinued December 2025) and intermittent degludec (Tresiba) supply constraints have driven some patients and providers back toward NPH as an affordable backup.
• OTC availability: Walmart's ReliOn Novolin N (~$25/vial OTC) provides a consistent safety net for uninsured patients. However, this does not appear in pharmacy inventory systems and requires patients to go in person.

Clinical Considerations: NPH vs. Basal Insulin Analogs

The 2025 ADA Standards of Care acknowledge that attainment of fasting glucose goals can be achieved with human NPH insulin or long-acting insulin analogs. Long-acting analogs (U-100 glargine and detemir) are associated with reduced nocturnal hypoglycemia versus NPH in clinical trials. Longer-acting analogs (U-300 glargine and degludec) convey even lower nocturnal hypoglycemia risk.

Key clinical trade-offs for providers weighing NPH vs. analogs:

• Cost: NPH at Walmart costs as little as $25/vial OTC. Analogs cost $35+/month even with manufacturer savings programs. For uninsured or underinsured patients, NPH remains a clinically appropriate, cost-effective choice.
• Hypoglycemia risk: NPH has higher day-to-day variability and greater nocturnal hypoglycemia risk due to its pronounced peak at 4-12 hours. Monitor carefully, especially for patients at high hypoglycemia risk (elderly, renal impairment, irregular meals).
• Pharmacokinetic variability: Inadequate resuspension of NPH contributes to its higher day-to-day variability. Educate patients on proper rolling technique (10 gentle rolls to ensure uniform cloudiness) before each injection.
• Dosing schedule: NPH is typically given once or twice daily. Type 1 patients require 0.4-1.0 units/kg/day; Type 2 patients typically start at 0.1-0.2 units/kg/day. Twice-daily dosing may be necessary in Type 1 to provide adequate 24-hour basal coverage.

Switching from NPH to a Basal Insulin Analog: Prescribing Guidance

When a patient cannot obtain NPH and a switch to a long-acting analog is indicated:

• NPH → Insulin Glargine U-100 (Lantus, Basaglar): Start glargine at 80% of the total daily NPH dose given once daily. For patients on twice-daily NPH, sum the doses and start glargine at 80% of the total. Titrate based on fasting glucose.
• NPH → Insulin Detemir (Levemir): Start at the same unit dose. Some patients require twice-daily detemir for adequate 24-hour coverage. Note: Novo Nordisk is phasing out Levemir; it was fully discontinued in the US in late 2024.
• NPH → Insulin Degludec (Tresiba): For type 1, use 80% of total daily NPH dose; for type 2, start at the same total daily dose. Note ongoing Tresiba supply intermittency as of early 2026.

Patient Communication: What to Tell Your NPH Patients

Proactively communicate the following to patients on NPH insulin:

1. "If your pharmacy is out of your NPH insulin, call us before skipping a dose."
2. "Walmart sells Novolin N under the ReliOn brand for about $25 per vial without a prescription."
3. "If you can't find your brand, we can switch you to the other NPH brand or temporarily to a glargine product."

For a tool that helps your patients find NPH insulin in stock at pharmacies near them, consider directing them to medfinder. medfinder calls pharmacies on the patient's behalf to locate which ones have the medication in stock.