All FDA-Approved Insulin Biosimilars in 2025: Complete List

What Is an Insulin Biosimilar?

An insulin biosimilar is a biological medicine that is highly similar to an already-approved insulin product — the "reference product" — with no clinically meaningful differences in safety, purity, or potency. Unlike generic small-molecule drugs, biologics like insulin are complex proteins made from living cells, which means biosimilars require extensive clinical testing to earn FDA approval rather than simple chemical matching.

The FDA approves insulin biosimilars through the 351(k) pathway under the Biologics Price Competition and Innovation Act (BPCIA). Some products earn the additional designation of interchangeable biosimilar, meaning pharmacists can substitute them for the reference product without a physician's intervention — just like a generic drug. This distinction matters enormously for patients at the pharmacy counter.

Why Biosimilars Matter for Diabetes

Insulin prices in the United States have historically been among the highest in the world. While the Inflation Reduction Act of 2022 capped Medicare insulin costs at $35/month and several manufacturers voluntarily reduced list prices, biosimilar competition remains one of the most powerful long-term tools for driving down costs. Studies published in JAMA Internal Medicine and by the RAND Corporation have consistently shown that biosimilar market entry reduces reference product prices by 20–40% over time as competition increases.

Complete List of FDA-Approved Insulin Biosimilars (2025)

Insulin Glargine Biosimilars (Long-Acting)

• Basaglar (insulin glargine-yfgn) — Eli Lilly / Boehringer Ingelheim. Approved 2015. The first insulin biosimilar approved in the US, referencing Lantus (Sanofi). Approved based on the ELEMENT clinical trial program, which demonstrated equivalent glycemic control to Lantus in both Type 1 and Type 2 diabetes. Available as a KwikPen.
• Semglee (insulin glargine-yfgn) — Viatris / Biocon. Approved July 2021. Semglee made history as the first FDA-designated interchangeable insulin biosimilar, referencing Lantus. The interchangeable designation was supported by data from the INSTRIDE clinical trial program. Semglee is available at significantly reduced list prices compared to Lantus and is widely covered under pharmacy benefit plans.
• Rezvoglar (insulin glargine-aglr) — Eli Lilly. Approved December 2022, launched 2023. References Lantus. Lilly priced Rezvoglar at $92 per five-pack of pens — roughly 78% below Lantus's list price — making it one of the most aggressively priced insulin biosimilars to date.

Insulin Aspart Biosimilars (Rapid-Acting)

• Insulin aspart-aabb (Trurapi) — Biocon Biologics. FDA approved in January 2024, referencing NovoLog (insulin aspart by Novo Nordisk). Trurapi received interchangeable biosimilar designation, supported by pharmacokinetic and pharmacodynamic bridging studies plus clinical safety data. This was a significant milestone, bringing rapid-acting interchangeable biosimilars to US patients for the first time.

Insulin Lispro Biosimilars (Rapid-Acting)

• Admelog (insulin lispro-aabc) — Sanofi. Approved December 2017, referencing Humalog (Eli Lilly). Admelog was the first rapid-acting insulin biosimilar approved in the United States. It is approved for adults with Type 1 and Type 2 diabetes and is available in vials and SoloStar pens. Note: Admelog does not currently carry an interchangeable designation.
• Lyumjev (insulin lispro-aabc) — Note: Lyumjev is Lilly's own ultra-rapid formulation and is NOT a biosimilar — it is a new formulation. It is included here only to clarify common patient confusion.

Current Status (2025)

As of 2025, there are four distinct insulin biosimilars with FDA approval in the United States: Basaglar, Semglee, Rezvoglar (all glargine-based), and Admelog (lispro-based), with Trurapi (aspart-based) the newest addition. Semglee and Trurapi hold interchangeable designations, the highest FDA endorsement for biosimilar substitution. Additional biosimilar applications — including for insulin degludec (referencing Tresiba) — are in various stages of FDA review or clinical development as of 2025. Novo Nordisk's own authorized generics and Civica Rx's nonprofit insulin project are also expanding the low-cost insulin landscape, though these are distinct from the biosimilar pathway.

What This Means for Patients

If you manage diabetes and rely on insulin, biosimilars represent real potential savings right now — not in the future. Here's what you should do today:

• Ask your pharmacist whether an interchangeable biosimilar is available for your prescribed insulin. For Lantus users, Semglee can be substituted at the pharmacy level in most states without a new prescription.
• Check your formulary. Many Medicare Part D and commercial plans now prefer biosimilars over brand-name insulins, meaning biosimilars may have lower copays for you.
• Don't assume switching is risky. FDA interchangeable designation means the agency has determined that switching produces the same clinical result. Discuss with your endocrinologist if you have specific concerns.
• Device compatibility matters. Different insulin pens use different cartridge systems. If you use pen devices, confirm that the biosimilar's delivery device is compatible with your supplies. Resources like mdsdiabetes.com can help you identify compatible pen needles and supplies for biosimilar devices.

Honest Assessment: What's Still Missing

Despite progress, significant gaps remain. There is still no FDA-approved biosimilar for insulin degludec (Tresiba), insulin detemir (Levemir — though Levemir is being discontinued by Novo Nordisk), or the combination insulin market. The pipeline is active, but regulatory timelines are often longer than anticipated. Patients tracking biosimilar development can monitor the FDA's Purple Book database online and search ClinicalTrials.gov using terms like "insulin biosimilar" to find ongoing studies they may qualify for.