Micro Doses, Macro Potential? Considerations for Microdosing Tirzepatide in Multi‐Dose Pens

1. Introduction

The obesity medication landscape continues to evolve, with several novel molecules under development and new formulations of previously approved nutrient‐stimulating hormone‐based (NuSH) therapies coming to market, including glucagon‐like peptide‐1 receptor agonists (GLP‐1RA) and dual glucose‐dependent insulinotropic polypeptide (GIP)/GLP‐1RA. Though markedly improved, high costs, inequitable coverage, and inconsistent recognition as a chronic disease state remain barriers to NuSH therapy access for many people with overweight, obesity, and related conditions such as atherosclerotic cardiovascular disease, metabolic‐associated steatohepatitis, and obstructive sleep apnea (OSA). Demand and associated affordability challenges are expected to rise as NuSH therapy use increases for unapproved, exploratory indications like chronic pain, neurodegenerative diseases, and substance use disorders [1, 2, 3, 4]. Further, tolerability of NuSH therapies is a common concern, as gastrointestinal (GI) side effects can be dose‐limiting. In these instances, microdosing may have potential.

2. When Less Is More

An emerging strategy to mitigate barriers related to NuSH therapy is microdosing, an off‐label technique where lower or fractional doses are used to improve access, affordability, and/or tolerability [5]. Despite the paucity of pharmacodynamic, pharmacokinetic, safety, and efficacy studies evaluating this approach, microdosing GLP‐1RA and GIP/GLP‐1RA has been advertised by direct‐to‐consumer telehealth companies and on social media platforms and implemented in clinical practice without peer‐reviewed, evidence‐based guidance. As microdosing gains traction, clinicians should be aware of the techniques, benefits, risks, and implications associated with this practice.

The rationale for microdosing semaglutide in multi‐dose pens has been described previously [5]. The same concept applies to tirzepatide in multi‐dose pens (tirzepatide‐MDP), which became commercially available in the U.S. in February 2026. Often referred to as “counting clicks,” microdosing tirzepatide‐MDP has been characterized by individuals sharing personal experiences online, though formal guidelines do not exist. This article should not be interpreted as clinical guidance for microdosing practices but should instead serve as a resource for clinicians who may consider microdosing tirzepatide‐MDP for patients who would benefit from this alternative dosing strategy.

3. Microdosing Potential of Tirzepatide‐MDP

Tirzepatide‐MDP is the first approved GIP/GLP‐1RA and is available in six strengths (2.5, 5, 7.5, 10, 12.5, and 15 mg) [6]. Each tirzepatide‐MDP device contains 2.4 mL of solution and four weekly doses, delivering up to 60 unnumbered “clicks” of medication per approved dose (Figure 1). Unlike the original autoinjector device, the dial‐up feature with tirzepatide‐MDP allows for dosing customization. Approved tirzepatide doses are not clearly marked, as the dose indicator begins at zero and ends at one (representative of the full dose) for all tirzepatide‐MDP devices [6]. Pen needles are not included in tirzepatide‐MDP packaging; thus a prescription is necessary. Currently, tirzepatide‐MDP is available for cash payers through LillyDirect and other retail pharmacies at promotional prices when dispensed within 45 days of the last refill or at higher standard pricing when refilled less frequently [4, 7]. In the U.S., once‐per‐lifetime free trial vouchers for tirzepatide‐MDP 2.5 mg are available in limited quantities through the manufacturer's local sales representatives.

FIGURE 1.

An example of patient instructions for microdosing tirzepatide in multi‐dose pens. This graphic can be shared with people living with overweight, obesity, or obstructive sleep apnea who may require instruction on microdosing tirzepatide in multi‐dose pens. Microdosing instructions should be reviewed verbally, provided in writing, and documented in the medical record along with patient consent and understanding of this off‐label dosing strategy.

Tirzepatide‐MDP is intended for single‐patient use, and the manufacturer recommended beyond use date (BUD) is 30 days at room temperature after the first injection [6]. Per package labeling, tirzepatide‐MDP solution should not be transferred to a syringe, used after completing four doses, or split into smaller doses, as the device was neither designed nor studied for these functions [6]. With clear prescribing parameters available from the manufacturer, the concept of microdosing tirzepatide‐MDP is complicated by scientific uncertainty related to altered dosing schedules and a void of evidence supporting cardiometabolic benefit with fractional doses. Nevertheless, individuals have employed microdosing with tirzepatide‐MDP due to several benefits associated with this strategy.

4. Advantages of Microdosing Tirzepatide‐MDP

Benefits of microdosing tirzepatide‐MDP include improving tolerability for people with historical or high risk of adverse effects, allowing for reintroduction of treatment after disruption without needing a new prescription, and flexibility when standard doses are not preferred for initial or maintenance therapy [5]. Further, tirzepatide for chronic weight management and OSA is available in multiple formulations (autoinjectors, multi‐dose pens, vials) directly from the manufacturer and is significantly more affordable, improving access and providing an alternative to compounded products as the Food and Drug Administration cracks down on unapproved NuSH therapies [8].

5. Limitations, Medicolegal Implications, and Regulatory Considerations

While microdosing tirzepatide‐MDP supports a tailored approach to care, there are various risks to consider including the possibility of contamination, infection, and compromised integrity if used after the BUD, even with aseptic techniques and refrigeration between uses. Additionally, there is a higher probability of dosing errors particularly for individuals with suboptimal vision and dexterity and low health literacy, warranting careful patient selection and close follow up [5]. Counseling regarding proper injection preparation and administration should be provided using a tirzepatide‐MDP demonstration device and the teach‐back method with written instructions prior to initiation. Patients may still experience intolerance; therefore, the usual education regarding mitigation of adverse effects must be provided in addition to microdosing counseling. If available, advanced practice providers (clinical pharmacists, nurse practitioners, and physician assistants) should be leveraged for dose adjustments and monitoring between physician visits. For individuals unable to achieve their goals through microdosing, transition to alternative obesity medications should be considered.

Microdosing tirzepatide‐MDP is not endorsed by the manufacturer or approved by any regulatory agency [5, 6]. While microdosing is a reasonable approach to individualizing care, the lack of supporting data should give pause to inexperienced users, considering the possible medical and legal implications and liability for dosing errors or adverse events experienced by patients [9]. Lastly, microdosing to extend supply may interfere with calculated days' supply estimations submitted to insurers. While not a concern for cash payers, prescribers and dispensing pharmacies should be cognizant of the impact for individuals with tirzepatide‐MDP coverage in the future.

6. Conclusion

Microdosing is an emerging strategy used in clinical practice to improve NuSH therapy access, affordability, and tolerability. The tirzepatide‐MDP device affords a patient‐centered approach to care through customization of therapy for individual needs and circumstances. Despite the potential benefits, prescribers should be aware of potential challenges associated with microdosing any GLP‐1RA and GIP/GLP‐1RA. As demand increases and NuSH therapy indications expand, observational and real‐world studies evaluating the safety and effectiveness of microdosing are needed.

Author Contributions

A.M.K. wrote the first draft of the manuscript. A.B.L. reviewed the first draft and developed the figure for this manuscript. S.T.L. and A.V.R. were involved in conception, reviewing, and editing the manuscript. A.M.K. is the guarantor of this work and takes full responsibility for the integrity and accuracy of the data presented.

Funding

The authors have nothing to report.

Conflicts of Interest

A.M.K. has received advisory/consulting fees from Camurus Pharmaceuticals, Dexcom Inc., Eli Lilly and Company, and Lexidrug/Wolters‐Kluwer. A.B.L., A.V.R., and S.T.L. declare no conflicts of interest.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.