Alternatives to Humulin N If You Can't Fill Your Prescription

Missing a dose of insulin is never acceptable — but what do you do when you've checked several pharmacies and nobody has Humulin N? The good news is that there are alternatives, both within the same NPH insulin class and in newer basal insulin classes. This guide walks through your options and what to discuss with your healthcare provider.

Important note: Never switch insulin types, brands, or doses without first consulting your doctor or pharmacist. Different insulins have different onset, peak, and duration profiles. An improper switch can cause dangerous hypoglycemia or hyperglycemia.

Option 1: Novolin N (The Closest Alternative)

Novolin N, made by Novo Nordisk, contains the exact same active ingredient as Humulin N: insulin isophane human (NPH). Both are intermediate-acting human insulins with the same 100 units/mL concentration, similar onset (1-3 hours), peak (4-12 hours), and duration (12-18 hours).

Novolin N is also available over the counter, and Walmart carries it under the ReliOn brand at approximately $25 per 10 mL vial — no prescription required. This makes it the most accessible emergency alternative to Humulin N for most patients.

Despite their pharmacological similarity, some patients experience subtle differences between NPH insulin brands. Always let your doctor know you switched and monitor your blood sugar more closely than usual during the transition.

Option 2: Basaglar (Insulin Glargine) — Long-Acting Analog

Basaglar (insulin glargine) is a long-acting basal insulin made by Eli Lilly. Unlike NPH insulin, Basaglar has no pronounced peak — it provides a relatively flat, steady insulin release over approximately 24 hours. This makes it easier to dose once daily and often reduces the risk of nocturnal hypoglycemia compared to NPH.

Basaglar is covered by the Eli Lilly Insulin Value Program, which caps monthly costs at $35 for commercially insured patients and those paying cash. It requires a prescription. If you're on Humulin N twice daily, your doctor will need to recalculate your dose when switching to Basaglar.

Option 3: Lantus (Insulin Glargine) — Long-Acting Analog

Lantus is the original insulin glargine, approved in 2000 and made by Sanofi. Like Basaglar, it is a once-daily long-acting insulin with a flat, peakless action profile lasting approximately 24 hours. Lantus biosimilars — including Semglee and Rezvoglar — are also FDA-approved and interchangeable with Lantus, potentially offering lower costs.

Lantus and Basaglar are generally considered clinically equivalent but are NOT considered interchangeable with each other by the FDA — a pharmacist cannot automatically substitute one for the other without prescriber approval. Both require a prescription.

Option 4: Tresiba (Insulin Degludec) — Ultra-Long-Acting

Tresiba (insulin degludec) is an ultra-long-acting basal insulin made by Novo Nordisk. It provides blood sugar control for up to 42 hours with an extremely flat action profile, which makes it very forgiving if you occasionally miss a dose or take it at different times.

Tresiba is generally used once daily and has among the lowest hypoglycemia rates of all basal insulins studied in clinical trials. It is more expensive than NPH or Basaglar without manufacturer assistance, but Novo Nordisk offers a savings program. Requires a prescription.

Comparison: Humulin N vs. Alternatives

Here's a quick overview of how these alternatives compare to Humulin N:

Novolin N: Same drug class, OTC available, lowest-cost option, similar dosing schedule. Best direct replacement.

Basaglar or Lantus: Once-daily, peakless, lower hypoglycemia risk than NPH. Requires prescription and dose recalculation.

Tresiba: Ultra-long-acting, very stable, lowest hypoglycemia risk. Best for patients who need flexibility. Requires prescription.

What to Tell Your Doctor When Requesting an Alternative

When you call your doctor about a Humulin N shortage, be prepared to share:

Your current dose (units per injection) and how many times per day you inject

How many days of Humulin N you have remaining

Which pharmacies near you do have available alternatives

Your most recent A1C and blood sugar levels if available

This information helps your doctor make the safest recommendation quickly — which is especially important in an urgent situation.

The Bottom Line

If you can't find Humulin N at your pharmacy, Novolin N is your most accessible same-class alternative and can be purchased OTC at Walmart. For a longer-term switch, Basaglar, Lantus, or Tresiba are all effective basal insulins — but require a new prescription and dose adjustment. Before exploring alternatives, try using medfinder to check pharmacies near you first. You can also read our guide: How to Find Humulin N In Stock Near You.