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Onswik ™ (insulin efsitora alfa-gobe) injection
500 units/mL (U-500), 1,000 units/mL (U-1,000)
This information is provided in response to your request. Resources may contain information about doses, uses, formulations and populations different from product labeling. See Prescribing Information above, if applicable.
Are the U-500 and U-1000 formulations of ONSWIK™ (insulin efsitora alfa-gobe) bioequivalent?
The U-500 and U-1000 formulations of efsitora are bioequivalent. Patients can transfer between the 2 concentrations using a 1:1 unit conversion, and no dose conversion is required.
Content Overview
- Does the efsitora dose need to be changed when switching between U-500 and U-1000?
- What did the efsitora bioequivalence study show?
- Why are 2 efsitora concentrations available?
- Enclosed Prescribing Information
- References
Does the efsitora dose need to be changed when switching between U-500 and U-1000?
No dose conversion is required if transferring a patient between the U-500 and U-1,000 strengths when each is administered at the same units/kg dose.1
The bioequivalence of the 2 formulations supports transfer between U-500 (500 units/mL) and U-1000 (1000 units/mL) using a 1:1 unit conversion.2
What did the efsitora bioequivalence study show?
Bioequivalence was assessed in a randomized, double-blind, 2-period, 2-sequence crossover study in healthy subjects (NCT05615532). The study design was as follows:
- 66 healthy subjects were enrolled, with a mean age of 44.8 years (SD 10.6)
- each subject received a single 100-unit subcutaneous dose of U-500 efsitora and a single 100-unit subcutaneous dose of U-1000 efsitora, in a crossover sequence, and
- blood was sampled for pharmacokinetic assessment for 65 days, approximately 9 weeks, after each dose.2
Mean pharmacokinetic profiles were similar after dosing with the U-500 and U-1000 formulations. All 90% confidence intervals for the ratios of total efsitora exposure and of maximum efsitora concentration were contained within the bioequivalence limits of 0.80 to 1.25. Tolerability of the 2 formulations was comparable.2
Efsitora 500 units/mL is bioequivalent to efsitora 1000 units/mL following administration of a single 100-unit dose, for the area under the plasma efsitora concentration-time curve from time zero to infinity and for maximum efsitora concentration.2
Why are 2 efsitora concentrations available?
The U-1000 formulation is an alternate dose strength of efsitora that provides an option for patients with diabetes who require a higher basal insulin dose.2
The U-500 KwikPen delivers doses in 5-unit increments and can deliver up to 400 units in a single injection. The U-1,000 KwikPen delivers doses in 10-unit increments and can deliver up to 800 units in a single injection.1
Enclosed Prescribing Information
ONSWIK™ (insulin efsitora alfa-gobe) injection, for subcutaneous use, Lilly
References
The published references below are available by contacting 1-800-LillyRx (1-800-545-5979).
- Onswik [package insert]. Indianapolis, IN: Eli Lilly and Company; 2026.
- Leohr J, Ghosh A, Waters DG, et al. Bioequivalence of insulin efsitora alfa (efsitora) U-500 and U-1000 formulations. Diabetes. 2025;74(suppl 1):801-P. American Diabetes Association abstract 801-P. https://doi.org/10.2337/db25-801-P
Date of Last Review: September 10, 2026