Alternatives to Basaglar If You Can't Fill Your Prescription

When your pharmacy is out of Basaglar KwikPens, your insulin supply is too important to wait and hope. The good news: there are several long-acting insulin alternatives that your provider can prescribe — and switching is manageable with the right information. This guide covers the main alternatives to Basaglar, how they compare, and what questions to ask your prescriber.

Important: Do not switch insulin products on your own. Every switch requires a new prescription and close glucose monitoring. Always work with your healthcare provider when changing insulins.

Why Can't a Pharmacist Just Substitute Another Insulin for Basaglar?

Basaglar is classified as a "follow-on" insulin glargine — not an FDA-designated interchangeable biosimilar. This means pharmacists cannot substitute Basaglar for Lantus or any other insulin without explicit prescriber authorization. Even insulin glargine products with the same amino acid sequence require a new prescription to switch between brands. This is different from regular generic drugs, where substitution is routine.

Basaglar Alternative #1: Lantus (Insulin Glargine, Sanofi)

Lantus is the original insulin glargine product from Sanofi and has an identical amino acid sequence to Basaglar. Both are 100 units/mL (U-100) and injected once daily. Switching from Basaglar to Lantus is typically a 1:1 unit conversion — your provider may start you at the same dose.

• Availability: Generally available in 2026 (vials and SoloStar pens)
• Cost: Higher list price than Basaglar; Sanofi Valyou Savings Program offers $35/month for uninsured and insured patients
• Dose conversion: 1:1 from Basaglar (same concentration, same mechanism)
• Watch for: May also be in localized short supply due to post-Semglee demand surge

Basaglar Alternative #2: Rezvoglar (Insulin Glargine-aglr, Eli Lilly)

Rezvoglar is an FDA-approved biosimilar to Lantus, also made by Eli Lilly. It is designated as interchangeable with Lantus, meaning pharmacists CAN substitute it for Lantus without a new prescription. However, if your prescription is specifically for Basaglar, a new prescription for Rezvoglar is still needed.

• Availability: Generally available; Lilly confirms KwikPens in stock
• Dose conversion: 1:1 from Basaglar (U-100 glargine)
• Cost: Often lower cost than brand Lantus; Lilly savings programs may apply

Basaglar Alternative #3: Toujeo (Insulin Glargine U-300, Sanofi)

Toujeo is a concentrated form of insulin glargine — 300 units/mL compared to Basaglar's 100 units/mL. It has the same active ingredient but a different pharmacokinetic profile, potentially providing a slightly longer, flatter action curve. Switching requires dose adjustment and careful monitoring.

• Dose conversion: NOT 1:1. When switching from Basaglar (U-100) to Toujeo (U-300), start with 80% of the Basaglar unit dose.
• Availability: Generally available in SoloStar and Max SoloStar pens
• Watch for: Dose conversion must be done by your provider — never attempt on your own

Basaglar Alternative #4: Tresiba (Insulin Degludec, Novo Nordisk)

Tresiba (insulin degludec) is an ultra-long-acting basal insulin with a duration of action exceeding 42 hours. Unlike Basaglar, Tresiba is not an insulin glargine product — it has a completely different mechanism and molecular structure. It allows more flexible dosing timing (within a window of up to 8 hours), which can be useful for patients with irregular schedules.

• Available as: FlexTouch pens in U-100 and U-200 strengths
• Dose conversion: Typically 1:1 from Basaglar when converting to Tresiba U-100; your provider will guide adjustment
• Availability: Generally available as of 2026

Basaglar Alternative #5: Levemir (Insulin Detemir, Novo Nordisk)

Levemir (insulin detemir) is another long-acting basal insulin option. Some patients may require twice-daily Levemir dosing for adequate blood sugar control, compared to Basaglar's once-daily schedule. Availability varies by region, so check stock before requesting a switch.

• Watch for: Some patients need twice-daily dosing with Levemir — your provider will assess
• Dose conversion: Start at same unit dose as Basaglar; monitor closely

Quick Comparison Table

Here is a side-by-side summary of Basaglar and its main alternatives:

• Basaglar KwikPen (Eli Lilly) — U-100 glargine, once daily, generally available
• Lantus SoloStar (Sanofi) — U-100 glargine, once daily, 1:1 dose conversion from Basaglar
• Rezvoglar KwikPen (Eli Lilly) — U-100 glargine biosimilar, once daily, 1:1 conversion
• Toujeo SoloStar (Sanofi) — U-300 glargine, once daily, start at 80% of Basaglar dose
• Tresiba FlexTouch (Novo Nordisk) — U-100/U-200 degludec, once daily, flexible timing
• Levemir FlexTouch (Novo Nordisk) — U-100 detemir, once or twice daily, varies by patient

What to Tell Your Provider

When calling or visiting your provider to request a switch, be prepared to share:

• Your current Basaglar dose (in units)
• Which pharmacies you've tried and their availability status
• Your insurance formulary preference (some alternatives may have better coverage)
• How many days of insulin you have remaining (so your provider knows the urgency)

Before requesting a switch, it's worth trying harder to find Basaglar in stock. Check our guide on why Basaglar is hard to find, or use medfinder to check multiple pharmacies near you before making the call.