Alternatives to Insulin Glargine If You Can't Fill Your Prescription

Running out of Insulin Glargine is a medical emergency waiting to happen. If your pharmacy is out of stock and you can't quickly locate your usual product, your doctor may recommend a safe alternative. This guide explains your options — and what to ask your healthcare provider before making any switch.

Important: Never switch insulin types or doses without talking to your doctor first. Different insulin products have different concentrations, action profiles, and dose equivalences. Even switching between U-100 glargine products requires confirmation from your care team.

Option 1: Switch to a Different Insulin Glargine Product (Easiest)

If one glargine product is unavailable, others may be in stock at your pharmacy or a nearby one. The following products all contain insulin glargine at 100 units/mL (U-100) and are generally dose-equivalent:

• Lantus (insulin glargine) — Brand by Sanofi; widely available as 10 mL vials and SoloStar prefilled pens
• Basaglar (insulin glargine) — Eli Lilly's KwikPen format; good availability; $35/month Lilly program
• Rezvoglar (insulin glargine-aglr) — FDA-interchangeable biosimilar by Eli Lilly; growing availability
• Langlara (insulin glargine-aldy) — Newest FDA-approved interchangeable biosimilar (May 4, 2026); entering the market
• Generic Insulin Glargine — Available from Winthrop and other manufacturers; often lowest cost with GoodRx coupons

Since all U-100 glargine products have the same active ingredient and concentration, switching between them is usually a 1:1 unit dose. However, always confirm with your pharmacist or doctor that the product you are receiving is indeed U-100, not U-300 (Toujeo).

Option 2: Switch to Toujeo (Insulin Glargine U-300)

Toujeo contains the same active ingredient (insulin glargine) but at 300 units/mL — three times as concentrated as standard products. This is NOT a 1:1 dose switch. When switching from U-100 glargine to Toujeo, some patients may need a dose adjustment. Toujeo provides a longer, smoother action profile and may cause less nocturnal hypoglycemia than U-100 glargine in some patients. Your doctor must oversee this switch.

Option 3: Switch to Insulin Detemir (Levemir)

Insulin Detemir (Levemir), made by Novo Nordisk, is another long-acting basal insulin. It works similarly to glargine but has a slightly shorter duration of action — many patients require twice-daily dosing. When switching from glargine to detemir, the starting dose is typically the same number of units, but close monitoring is essential in the first few weeks.

Option 4: Switch to Insulin Degludec (Tresiba)

Insulin Degludec (Tresiba), made by Novo Nordisk, is an ultra-long-acting insulin with a duration of action up to 42 hours. It has an even flatter action profile than glargine and very low day-to-day variability. Tresiba has itself experienced intermittent shortage issues, particularly in the U-200 formulation — so check availability before asking your doctor for a switch.

Option 5: NPH Insulin (Emergency Stopgap Only)

NPH insulin (Humulin N, Novolin N) is an intermediate-acting insulin that peaks 4–12 hours after injection and requires twice-daily dosing. It is available over the counter at Walmart (ReliOn brand) and at many pharmacies without a prescription. While NPH is NOT a replacement for glargine and requires careful titration, it can serve as a very short-term emergency option under physician guidance if no long-acting insulin is available.

Do not switch to NPH independently — the dosing and timing are substantially different from glargine, and doing so incorrectly can cause dangerous hypoglycemia or hyperglycemia.

Comparing Your Options at a Glance

• Same ingredient, easy switch: Basaglar, Rezvoglar, Langlara, generic glargine U-100 (1:1 dose)
• Same ingredient, dose adjustment: Toujeo U-300 (NOT 1:1 — requires provider guidance)
• Different insulin, close monitoring: Levemir (detemir), Tresiba (degludec)
• Emergency only, provider required: NPH (Humulin N, Novolin N)

Step-by-Step: What to Do If You Can't Get Insulin Glargine

1. Use medfinder.com to search for pharmacies near you that have your specific product in stock.
2. Call your doctor and explain the situation. Ask whether switching to an available glargine product (Basaglar, Rezvoglar) or a different basal insulin is appropriate.
3. Ask your pharmacist if they can special-order your medication within 24–48 hours.
4. If your situation is urgent, ask your doctor about available samples in their office.
5. Do not ration or skip doses while waiting — contact your care team immediately if you are running critically low.

Also read our Insulin Glargine shortage update for 2026 for the latest on availability.