Alternatives to Insulin Degludec if you can't fill your prescription

What to Do When You Can't Find Insulin Degludec

If you've been prescribed Insulin Degludec (Tresiba) and your pharmacy is out of stock, you may be wondering what your options are. First: don't panic, but don't skip your insulin either. Going without basal insulin can lead to dangerous blood sugar spikes, and for people with type 1 diabetes, it can cause diabetic ketoacidosis (DKA), a medical emergency.

The good news is that there are several effective alternative basal insulins available. Your doctor can help you transition safely. Here's what you need to know about each option.

For tips on locating Insulin Degludec before switching, see: How to Find Insulin Degludec in Stock Near You.

Understanding Basal Insulin

Basal insulin provides a steady, background level of insulin throughout the day and night. It mimics the low-level insulin that a healthy pancreas releases continuously. Insulin Degludec is an ultra-long-acting basal insulin with a duration of action exceeding 42 hours and a very flat pharmacokinetic profile, meaning fewer blood sugar peaks and valleys compared to other basal insulins.

When switching to an alternative, the key factors to consider are: duration of action, dosing frequency, variability, cost, and availability. For a deeper look at how Insulin Degludec works, check out How Does Insulin Degludec Work: Mechanism of Action Explained.

Alternative 1: Insulin Glargine U-100 (Lantus, Basaglar, Semglee)

Insulin Glargine is the most commonly prescribed basal insulin in the world and the most likely alternative your doctor will suggest. It forms microprecipitates after injection that dissolve slowly, providing approximately 24 hours of coverage.

Key Details

• Duration: ~24 hours
• Dosing: Once daily, same time each day
• Availability: Widely available; multiple brands and biosimilars
• Cost: Biosimilars (Semglee, Basaglar) are often significantly cheaper than Tresiba
• Pros: Well-studied, widely available, biosimilars reduce cost
• Cons: Slightly more day-to-day variability than Insulin Degludec; must be taken at a consistent time

For most patients, Insulin Glargine U-100 is the closest and most accessible substitute for Insulin Degludec.

Alternative 2: Insulin Glargine U-300 (Toujeo)

Toujeo is a concentrated formulation of Insulin Glargine (300 units/mL) that has a longer and flatter profile than standard Insulin Glargine U-100. It's the closest match to Insulin Degludec in terms of pharmacokinetics.

Key Details

• Duration: ~36 hours
• Dosing: Once daily
• Availability: Good; single brand (Toujeo by Sanofi)
• Cost: Similar to Tresiba (brand-only pricing)
• Pros: Longer duration and flatter profile than U-100 glargine; less nocturnal hypoglycemia
• Cons: No biosimilar; may require higher doses than Insulin Degludec

If you value the flat, ultra-long-acting profile of Insulin Degludec, Toujeo is often the best alternative.

Alternative 3: Insulin Detemir (Levemir)

Insulin Detemir is a long-acting basal insulin that has been used for decades. It binds to albumin in the bloodstream, which extends its duration of action.

Key Details

• Duration: ~12-24 hours (dose-dependent)
• Dosing: Once or twice daily
• Availability: Generally good
• Cost: Often less expensive than Tresiba
• Pros: Well-established safety profile; may cause less weight gain
• Cons: Shorter duration often requires twice-daily dosing; more variability than Insulin Degludec

Insulin Detemir is a reasonable option, though the potential need for twice-daily injections makes it less convenient than Insulin Degludec.

Alternative 4: NPH Insulin (Humulin N, Novolin N)

NPH Insulin is an intermediate-acting insulin that has been available for decades. While it's not a direct substitute for Insulin Degludec, it's the most affordable insulin option and is available over the counter at some pharmacies.

Key Details

• Duration: ~12-16 hours
• Dosing: Usually twice daily
• Availability: Excellent; widely stocked
• Cost: Very affordable ($25-$75 per vial at Walmart)
• Pros: Cheap, widely available, no prescription needed at some retailers
• Cons: Significant peak effect increases hypoglycemia risk; requires more frequent monitoring; much less predictable than Insulin Degludec

Important: Switching from Insulin Degludec to NPH is a significant change in insulin management. Do not attempt this switch without your doctor's guidance. NPH has a pronounced peak that Insulin Degludec does not, which changes your risk of hypoglycemia.

How to Switch Safely

Switching basal insulins should always be done under medical supervision. Here are general guidelines:

1. Contact your doctor before making any changes. They'll determine the equivalent dose and monitor your blood sugar during the transition.
2. Dose conversion is not always 1:1. For example, switching from Insulin Degludec to Insulin Glargine U-100 is typically a unit-for-unit conversion, but switching to Toujeo may require a dose increase of 10-15%.
3. Monitor blood sugar more frequently during the first 1-2 weeks of any insulin switch.
4. Watch for hypoglycemia, especially at night. Different insulins have different peak times.
5. Keep a log of your blood sugar readings and share it with your doctor.

Don't Stop Taking Basal Insulin

We can't stress this enough: never stop taking basal insulin because you can't find your preferred brand. If you have type 1 diabetes, you need basal insulin to survive. If you have type 2 diabetes, abruptly stopping basal insulin can lead to dangerously high blood sugar levels.

If you're in an emergency situation and running out, go to an urgent care center or emergency room. Some pharmacies can also provide emergency supplies under state-specific laws.

Still Looking for Insulin Degludec?

Before switching, it's worth trying to locate Insulin Degludec at other pharmacies. Use MedFinder to check real-time stock near you, or read our guide: How to Find Insulin Degludec in Stock Near You.

For money-saving strategies on any insulin, see How to Save Money on Insulin Degludec.