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  1. Medical Information Right
  2. Are the different Mounjaro® (tirzepatide) presentations bioequivalent?
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If you wish to report an adverse event or product complaint, please call 1-800-LILLYRX (1-800-545-5979)

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Mounjaro ® (tirzepatide) injection

2.5 mg/5 mg/7.5 mg/10 mg/12.5 mg/15 mg

Full Prescribing Information

Zepbound ® (tirzepatide) injection

2.5 mg/ 5 mg/ 7.5 mg/ 10 mg/ 12.5 mg/ 15 mg

Full Prescribing Information

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 different Mounjaro® (tirzepatide) presentations bioequivalent?

Based on bioequivalence studies, tirzepatide is expected to demonstrate comparable efficacy and safety across the different formulations.

US_cFAQ_TZP360A_M_INGREDIENTS_ALL_PRESENTATIONS_T2D_v1_0_CLEAN

See important safety information, including boxed warning, in the attached prescribing information.

Content Overview

  • What Mounjaro (Tirzepatide) Presentations Are Approved?
  • Which Tirzepatide Presentation Was Used In Clinical Studies?
  • Does Benzyl Alcohol Increase the Risk of Metabolic Acidosis?
  • Can Patients Switch Between Tirzepatide Presentations?
  • Enclosed Prescribing Information
  • References

What Mounjaro (Tirzepatide) Presentations Are Approved?

Mounjaro (tirzepatide) is approved by the Food and Drug Administration (FDA) in a 

  • single-dose pen
  • multiple-dose pen
  • single-dose vial, and
  • multiple-dose vial.1

The pens and the vials have the identical active ingredient, tirzepatide, and are designed to deliver the same doses.1

Regardless of presentation, tirzepatide is administered subcutaneously once weekly, and the dosing regimen and administration sites (abdomen, thigh or back of upper arm) remain the same.1

The FDA has approved the Mounjaro KwikPen and multiple dose vial.1

Back to Content Overview

Which Tirzepatide Presentation Was Used In Clinical Studies?

Phase 3 clinical trials of tirzepatide for type 2 diabetes were conducted using the tirzepatide single-dose pen.2-7

The tirzepatide multidose presentations and the tirzepatide single-dose presentations have the identical active ingredient, tirzepatide, and are designed to deliver the same doses as the single-dose pen that was tested in the SURPASS clinical trial program in adults with type 2 diabetes.1-7

Based on the results of bioequivalence studies, the efficacy and safety of tirzepatide administered between the autoinjector and other presentations can be expected to be comparable.

This includes the same excipients, excipient concentrations, and drug substance concentration.8

The single-dose vial and single-dose pen

  • contain 1 fixed dose
  • have a dosing volume of 0.5 mL per dose
  • are for single use only, and
  • do not contain preservatives.1

Differences between the single-dose presentations and multi-dose presentations include

  • the dosing volume and
  • the addition of the preservatives, phenol and benzyl alcohol, and the tonicity agent, glycerin as summarized in Table 1.8
Table 1. Tirzepatide Formulation Ingredients8

 

Tirzepatide Single-dose Pen or Vial (Nonpreserved Formulation)

Tirzepatide Multi-dose Pen or Vial
(Preserved Formulation)

Ingredienta

Quantity (per 0.5 mL)

Quantity (per 0.6 mL)

Tirzepatide

2.5 mg/5 mg/7.5 mg/10 mg/
12.5 mg/15 mg

2.5 mg/5 mg/7.5 mg/10 mg/
12.5 mg/15 mg

Dibasic sodium phosphate heptahydrate

0.7 mg

0.8 mg

Sodium chloride

4.1 mg

1.05 mg

Hydrochloric acid solution

as needed

as needed

Sodium hydroxide solution

as needed

as needed

Water for injection

as needed to 0.5 mL

as needed to 0.6 mL

Phenol

NA

1.08 mg

Benzyl alcohol

NA

5.4 mg

Glycerin

NA

4.8 mg

Abbreviation: NA = not applicable.

a Only the KwikPen contains preservatives (benzyl alcohol, phenol) and glycerin for tonicity.

Back to Content Overview

Does Benzyl Alcohol Increase the Risk of Metabolic Acidosis?

Eli Lilly and Company has no clinical trial data on the risk of metabolic acidosis associated with benzyl alcohol in tirzepatide multi-dose presentations.

Patients should ask their doctor, nurse or pharmacist for advice if they are pregnant or breast-feeding, or if they have kidney or liver problems. This is because large amounts of benzyl alcohol can build-up in their body and may cause metabolic acidosis.8

Back to Content Overview

Can Patients Switch Between Tirzepatide Presentations?

There are no data available regarding transitioning between the tirzepatide presentations, as these treatment scenarios have not been studied.

Eli Lilly and Company has created several different presentations to deliver tirzepatide, but cannot make a specific recommendation on which presentation of tirzepatide is best for each patient. The healthcare practitioner may use the information provided, the patient’s prior medical history and concomitant medications, and other individual factors in developing a treatment plan. The healthcare practitioner should consider potential risks and benefits of treatment options and monitor appropriately.

Tirzepatide presentations have the identical active ingredient and are designed to deliver the same doses. Regardless of presentation, tirzepatide is administered subcutaneously once weekly, and the dosing regimen and administration sites remain the same.8

Please follow the Mounjaro Prescribing Information for instructions on proper administration of tirzepatide.1

Patients should always consult their health care provider to understand the risks and benefits of tirzepatide and to determine whether they may benefit from tirzepatide, including the dose and delivery mechanism best suited for them.8

Prior to initiation of any formulation of tirzepatide, healthcare providers should train patients and caregivers on proper injection technique. Refer to your local label for instructions on proper storage, handling, and administration of tirzepatide via the KwikPen or the single-dose vial to ensure accurate and effective dosing of tirzepatide.

Back to Content Overview

Enclosed Prescribing Information

MOUNJARO® (tirzepatide) Injection, for subcutaneous use, Lilly

References

The published references below are available by contacting 1-800-LillyRx (1-800-545-5979).

  1. Mounjaro [package insert]. Indianapolis, IN: Eli Lilly and Company; 2026.
  2. Rosenstock J, Wysham C, Frías JP, et al. Efficacy and safety of a novel dual GIP and GLP-1 receptor agonist tirzepatide in patients with type 2 diabetes (SURPASS-1): a double-blind, randomised, phase 3 trial. Lancet. 2021;398(10295):143-155. https://doi.org/10.1016/S0140-6736(21)01324-6
  3. Frías JP, Davies MJ, Rosenstock J, et al; SURPASS-2 Investigators. Tirzepatide versus semaglutide once weekly in patients with type 2 diabetes. N Engl J Med. 2021;385(6):503-515. https://doi.org/10.1056/NEJMoa2107519
  4. Ludvik B, Giorgino F, Jódar E, et al. Once-weekly tirzepatide versus once-daily insulin degludec as add-on to metformin with or without SGLT2 inhibitors in patients with type 2 diabetes (SURPASS-3): a randomised, open-label, parallel-group, phase 3 trial. Lancet. 2021;398(10300):583-598. https://doi.org/10.1016/S0140-6736(21)01443-4
  5. Dahl D, Onishi Y, Norwood P, et al. Effect of subcutaneous tirzepatide vs placebo added to titrated insulin glargine on glycemic control in patients with type 2 diabetes: the SURPASS-5 randomized clinical trial. JAMA. 2022;327(6):534-545. https://doi.org/10.1001/jama.2022.0078
  6. Inagaki N, Takeuchi M, Oura T, et al. Efficacy and safety of tirzepatide monotherapy compared with dulaglutide in Japanese patients with type 2 diabetes (SURPASS J-mono): a double-blind, multicentre, randomised, phase 3 trial. Lancet. 2022;10(9):623-633. https://doi.org/10.1016/S2213-8587(22)00188-7
  7. Kadowaki T, Chin R, Ozeki A, et al. Safety and efficacy of tirzepatide as an add-on to single oral antihyperglycaemic medication in patients with type 2 diabetes in Japan (SURPASS J-combo): a multicentre, randomised, open-label, parallel-group, phase 3 trial. Lancet. 2022;10(9):634-644. https://doi.org/10.1016/S2213-8587(22)00187-5
  8. Data on file, Eli Lilly and Company and/or one of its subsidiaries.

Date of Last Review: August 31, 2026

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