The first injection pens, such as the NovoPen launched in1985, were designed to deliver insulin to people with Type 1 Diabetes (T1D).The design of these pens is the result of years of iteration, including human factors research focusing on the needs of users with the greatest accessibility challenges in a diverse user population that ranges from children – who may need help from caregivers – to elderly adults with conditions like arthritis, neuropathy, or visual impairments.
People with diabetes depend on these devices for survival, and the devices have been optimised accordingly for their ease of use, safety, and reliability. However, as GLP-1 drugs – originally intended to treat Type 2diabetes (T2D) and often delivered with injection pens developed for insulin[1] –are increasingly used to treat obesity, perhaps it is worth rethinking the basis of these designs to accommodate a user group who may have different requirements?
Could poor adherence to GLP-1 amongst those using it for weight loss – 30% stop within four weeks without achieving clinically meaningful weight loss[i] –be explained, in part, by a user experience that doesn’t cater to the specific needs of this population?
In this TTP Insight, we explore how the experiences and motivations of individuals using GLP-1 drugs for weight loss may differ from those managing diabetes or heart disease. If we focus on behavioural insights and understanding the specific challenges faced by this group, we can create amore tailored solution that could enhance user engagement and adherence, even disrupt market leaders, by better meeting the needs of people using GLP-1 therapies for weight management.
Market trends in GLP-1 usage
Recent market data suggests around 5% of US adults (~12.5M people)have used or are currently using GLP-1 for weight loss alone[i].This is higher than the 7.4M[ii]people (both adults and children) using insulin and equal to the 5% that have used or are currently using GLP-1 only to treat a chronic condition like diabetes or heart disease(~3% are using it to both treat a chronic condition AND to lose weight).
As T2D is often associated with having a high BMI, you’d be forgiven for assuming that the needs of people who use GLP-1 for weight loss and those using it to treat diabetes would be very similar, but recent market research suggests a number of significant differences.[iii]
§ Their data suggests the majority of those using GLP-1 for weight loss are in their 30s to 50s (whereas those using GLP-1 for diabetes control are more likely to be 60+).
§ The data also suggests people using GLP-1 for weight loss are twice as likely to have a high income (whereas those usingGLP-1 for diabetes control tend to be less well-off on average).
A further point of interest is the way in which younger people are using GLP-1 for weight loss vs. older people. The data indicates that younger people are using it as part of a wider strategy to be more proactive about their health.
§ A greater proportion of those using GLP-1 to target a weight loss of 7 kg (15 lbs) or less are younger (teens to thirties) compared to those using GLP-1 to target a weight loss greater than 7 kg (15 lbs).
§ Of those targeting a weight loss of less than 7kg (15 lbs), two-thirds already actively manage their health in some way, vs. half those targeting a higher amount.
These trends are accelerating: the percentage of users prescribed GLP-1 exclusively for weight loss grew from 10% in October 2022 to 43% in October 2023. Yet, in many countries the devices being used to deliver GLP-1 are the same for both weight loss and T2D populations, and in many cases, were originally designed for delivering insulin.
We think this represents an opportunity for more targeted drug delivery solutions to gain traction in the weight loss segment. Let’s consider the approaches we might take to realising it.
Unique requirements
Designing effective GLP-1 delivery solutions requires a deep understanding of the people who use them. While regulatory standards ensure safety and functionality, addressing the unique needs of GLP-1 users for weight loss offers an opportunity to go beyond compliance, creating solutions that are not only practical but also deeply engaging.
This user group presents distinct challenges and opportunities for design. Unlike diabetes patients, many of whom are well-acquainted with managing complex medication regimens, GLP-1 users for weight loss are often new to injecting and may have different levels of medical literacy, motivations, and expectations. By tailoring the use experience to their specific profiles, we can improve adherence, support better outcomes, and position them as tools for health empowerment.
TTP has developed a user engagement framework[i] that can be used to generate ideas for behavioural interventions at all stages of a task, ensuring products resonate on practical, emotional, and aspirational levels. This approach, grounded in behavioural science, addresses real-world barriers to medication adherence by mapping engagement touchpoints to drivers of motivation, providing a tool for design teams to think through problems and create solutions that not only function well but also encourage user participation.
Let’s explore some of the key differences between these user groups, the challenges and opportunities they represent for design, and examples of the type of interventions that could be drawn from the engagement framework.
Challenges
Greater anxiety around injections
People with diabetes often become familiar with managing complex medication regimens due to the ongoing need for blood glucose control. Frequent injections—sometimes 4-5 times a day—can lead to a level of routine and familiarity with the process, shaped by their frequent exposure. For some, the level of comfort even extends to injecting through clothing or in public settings, practices that have been studied for safety. In fact, some diabetes associations no longer emphasise the use of alcohol wipes before injection as part of standard practice[i].
However, for those on a weekly injection schedule, such familiarity may be harder to achieve. The less frequent need for injections can mean that users don’t develop the same level of comfort or routine, which may influence their overall experience and adherence. GLP-1 users are often new to injecting and may feel anxious or reluctant about the process. As GLP-1 has moved towards weekly dosing, users are less likely to experience the desensitisation that comes from repeated exposure.
One way to tackle the issue is to reduce exposure by making injections even less frequent. Companies are investing in GLP-1 formulations and devices that allow for less frequent dosing, such as quarterly injections. Developing devices that manage higher dose volumes, increased viscosity, and larger needle diameters represent engineering challenges that are the subject of a great deal of ongoing research. For a deeper exploration of these technical aspects, please refer to TTP’s drug delivery solutions page.
However, there are also ways to help anxious users feel in control while maintaining the current injection schedule. A review of postings by users on social media indicate that needle phobia is not necessarily as straightforward as not wanting to see the needle[i],as one Reddit user commented: “I am so scared to take my first shot because I can’t see the needle. Ozempic needles I can see so I have control. I have afear of needles so I’m having major anxiety”. For many, the uncertainty, tension and sudden release of an autoinjector is more anxiety inducing than injecting with an exposed needle. This need to be in control, referred to as “Autonomy” in TTP’s engagement framework6 is the most essential driver of intrinsic motivation[ii].
How might we design a drug delivery solution that maximises that sense of autonomy, while maintaining the simple workflow that autoinjectors offer? There are a number of areas that could be explored in a conceptual exploration, such as adding a retractable window that allows you to see the needle only if you want to. Or, reworking the trigger mechanism to ramp up smoothly rather than the current characteristic “snap!”
Poor adherence levels
For people with diabetes, injections are life critical. A study comparing adherence between people with T2D that use insulin with those using GLP-1 found that insulin users had an adherence level of around 90% compared to around 74% for those using GLP-1 (both oral and injectable versions)[i].
For those using GLP-1 for weight loss, injections are a choice. Levels of adherence are lower than for people with diabetes. Another study, applying the same metric of adherence to people using GLP-1 to treat obesity, found lower levels of adherence: 40.1% for Ozempic (a weekly injectable GLP-1 approved for the treatment of diabetes, in this case being used off-label for weight loss), 31.5%for weekly injectable Wegovy (essentially the same drug as Ozempic, with a higher standard dose) and just 15% for daily injectable Saxenda[ii]. This suggests greater expectation management is required to maintain users’ faith in the value and purpose of what they are doing.
Adherence is generally affected by a combination of capability (i.e., strength, dexterity, cognitive powers), opportunity (i.e., complexity, cost, availability) and motivation (i.e., intrinsic drivers, rewards, general mood)[iii].TTP have built a predictive model of adherence[iv]that calculates relative differences in likely adherence based on a quantitative analysis of typical disease impact, patient demographics, drug effects and device operating principles.
By systematically analysing a drug delivery solution we can identify opportunities for improvement and determine the cost-benefit of investing in a wide variety of design features. For example, in a previous analysis for a client interested in comparing off-the-shelf packaging options for a new drug, the model was able to show that the improvements cited by one potential supplier were explainable by basic low cost aspects of the device design (a simple reminder), rather than the costlier more innovative/complex parts cited in their marketing.
Lacking medical literacy
People with diabetes have a steep learning curve upon diagnosis, but over time, many develop a deep understanding of their condition and the way their bodies respond to carbohydrates, insulin, exercise and other factors. Training courses for patients diagnosed with type 1 diabetes are practically oriented and emphasise the critical importance of proper nutrition and recognizing and managing the signs of both low and high blood sugar.
GLP-1 users may not have such earnest study and medical knowledge thrust upon them. They are less likely to rely on authoritative sources of medical information and more likely to make risky medical choices based on opinions and experiences shared online. For example: “stacking” different brands of GLP-1 medications, using more than the prescribed dose or changing their dosing intervals without reference to a medical professional, as one Redditor commented[i]: “I did 10 my first shot, then 12. I just now gave myself 15 for week 3. If all goes well I’ll up it to 20 next week. I’m impatient and this is too expensive to be overly cautious.”
A balance must be struck between creating a comfortable experience – such as minimising medical aesthetics and any stigmatising elements – and ensuring that users fully understand their treatment and approach it with the seriousness it requires. A companion app that helps to guide new users through the first few weeks of learning the device, titrating the dose, and explaining what to expect, what to look out for and what kind of weight loss is reasonable, may be one way to help to manage expectations and keep users safe. Another might be electronically preventing non-standard dosing schedules or quantities.
The problem is also partly driven by cost. Many users find branded GLP-1 is not affordable and turn to lower cost sources such as getting semaglutide made upby a compounding pharmacy (often requesting additions to the formula like Vitamin B12), a practice that is not recommended by the FDA[ii].This may decrease as the first generic versions of GLP-1 drugs become available(these started to get approval by the FDA in late 2024). While there are typically serious limitations to what changes can be made to the method of operation for drug delivery devices, there may also be an opportunity for competing products to differentiate themselves through access to high-quality patient support materials and moderated forums.
Opportunities
Less need for portability
Insulin pens for rapid-acting insulin must be portable so users can easily carry them throughout the day. In contrast, pens for long-acting insulin, used once or twice daily, have fewer portability requirements, although often similar devices are used for both.
GLP-1 treatments for weight loss are typically injected at home once daily or weekly, meaning portability is less critical unless users are travelling. Reduced portability requirements allow for designs that are more engaging, supportive, and ergonomic, with more premium aesthetics driven by a consumer health mindset.
TTP conducts early-stage user research to determine the ideal size and features of injection devices. By understanding user preferences before detailed engineering begins, designers know the acceptable limits for device size and can make informed trade-offs if internal components require adjustments. This approach ensures the final product closely matches user expectations and, in subsequent user evaluations, has been shown to be significantly preferred over alternatives.
Sometimes improvements to user experience come from combining devices with digital technologies, such as smartphone apps, without changing the injection device itself. For example, TTP collaborated with L2S2 to create the "CoolMate" concept, designed to support people using biosimilars for autoimmune conditions. Home visits revealed significant user challenges, including managing medication refills, safe storage, correct usage order, and anxiety around maintaining cold storage conditions. Providing better support, especially in the initial phase of treatments like GLP-1, can greatly improve user experience, reduce anxiety, and help users stick with their treatment plans.
Fewer comorbidities affecting capability
People with diabetes are more likely to suffer from peripheral neuropathy (29.1% ofT1D, 42.2% of T2D) and retinopathy (28.4% of T1D, 23.8% of T2D)[iii]amongst other things. Devices must include high-contrast labels and tactile features for those with visual or dexterity impairments. Those using GLP-1 for weight loss may deal with obesity or hypertension but are less likely to have severe visual or dexterity issues. This means we may have a little more leeway and flexibility on aesthetic aspects of design.
Donald Norman coined the concept of “Emotional Design”[iv]which proposes that we engage with products at three levels:
§ Visceral – instinctive level: gut reactions driven by evolutionarily derived aesthetic preferences
§ Behavioural – purely utilitarian level: focused on functionality and ease of use
§ Reflective – intellectual level: incorporating cultural status, meaning, sentimental value and so on.
Medical device development focuses, correctly, on what Norman called the “Behavioural” level. However, there is also strong evidence that products with aesthetic appeal lead to enhanced usability[v],perhaps because users are more inclined to invest their time in learning how to use it. Often when we can’t understand the popularity of a product it is because we have neglected to consider one of these levels.
Having the freedom to invest in designs that tap into each level, particularly the “Reflective” level, could help with engagement. One could envisage ways in which this freedom could be used to create something more personal, or even a range of options to cover the design needs of different user segments and cultures.
Given the success of consumer-oriented wellness products and services, adopting a less medical “feel” to the experience and tuning in more to the aesthetics and sensibilities of lifestyle products could improve user adoption. Taking inspiration from fitness and wellness products like Strava ,Whoop, and Noom, devices could bolster users' self-identity as someone proactively managing their health, fostering a sense of empowerment and engagement.
Goal-oriented mindset
People with T2D are typically prescribed GLP-1 to stimulate their pancreas and to ward off worsening symptoms that may lead them to require using insulin down the line. They anticipate chronic use of the drug – at least until more intensive treatment becomes necessary.
In contrast, people using GLP-1 for weight loss may be more focused on achieving a specific goal: they hope to resolve an issue – obesity – rather than simply maintaining or prolonging their current health status. Their motivations can vary, driven by concerns such as health (50%), appearance (35%), or mood (15%)[vi]. As a result, they may not perceive their need as strictly medical and so may be put off by products with overtly medical aesthetics. Additionally, weight loss is generally seen as having a definitive endpoint, leading users to (rightly or wrongly) expect that treatment can be tapered down or discontinued once their goal is achieved. This goal-oriented approach brings a different psychological perspective compared to managing other chronic conditions.
A weight-loss focused GLP-1 device should emphasise progression and movement toward a goal, which may differ from designs for type2 diabetes users. Targeting specific segments—such as health, appearance, and mood—could further refine device positioning. For example, athlete-focused glucose monitors have been successfully adapted to prioritise performance optimisation over strictly medical functionality, offering a tailored approach distinct from those designed for diabetes management, although careful analysis and testing are needed so as not to undermine safety critical elements of the design or workflow.
Conclusion
By addressing the unique requirements of people using GLP-1 for weight loss, device teams can develop solutions that support better adherence and create a positive, engaging user experience. This article has shown that early integration of engagement strategies can lead to devices that resonate with users as tools for health empowerment.
TTP’s engagement framework integrates behavioural insights into medical device design, ensuring devices are not just safe, but also compelling and easy to use. By working with TTP, clients gain access to deep human factors expertise, predictive adherence modelling, and cutting-edge engineering solutions that optimize the patient experience.
While we have focused in this article on the differing requirements for people using GLP-1 for weight loss, the list of proposed indications for GLP-1 grows seemingly on a daily basis with research currently ongoing in neurodegenerative disease, chronic kidney disease and liver disease. Each of these patient groups will have unique needs, underscoring the importance of designing a diverse range of devices tailored to the specific requirements of each segment.
TTP is ready to work with you to design the next generation of GLP-1 delivery devices. Whether through user research, behavioural engagement modelling, or advanced engineering, we can develop solutions that improve adherence and enhance patient experience. Contact us to explore how we can innovate together.
References:
[1] E.g.,Novo Nordisk FlexTouch for Wegovy and Eli Lilly KwikPen for Mounjaro (outsidethe US).
[i]Blue HealthIntelligence. (2024). Real-World Trends in GLP-1TreatmentPersistence and Prescribing for Weight Management (Issue Brief).Blue CrossBlue Shield Association.https://www.bcbs.com/media/pdf/BHI_Issue_Brief_GLP1_Trends.pdf
[i]Montero, A.,Sparks, G., Presiado, M., & Published, L. H. (2024, May 10).KFF HealthTracking Poll May 2024: The Public’s Use and Views of GLP-1 Drugs. KFF.https://www.kff.org/health-costs/poll-finding/kff-health-tracking-poll-may-2024-the-publics-use-and-views-of-glp-1-drugs/
[ii]Grassley, C. E., & Wyden, R. (2021). Insulin:Examining the FactorsDriving the Rising Cost of a Century Old Drug. USSenate - Senate FinanceCommittee.https://www.finance.senate.gov/imo/media/doc/Grassley-Wyden%20Insulin%20Report%20(FINAL%201).pdf
[iii]Numerator. (2023, November 30). ConsumersUsing Glp-1 Medications for WeightLoss Skew Younger and Higher Income,Numerator Reports. GlobeNewswire NewsRoom.https://www.globenewswire.com/news-release/2023/11/30/2788682/0/en/CONSUMERS-USING-GLP-1-MEDICATIONS-FOR-WEIGHT-LOSS-SKEW-YOUNGER-AND-HIGHER-INCOME-NUMERATOR-REPORTS.html
[i]Lock, D. (2025, February 25) Designing foruser engagement in medical technologies – a framework people want to use. TTPInsights. https://www.ttp.com/insights/designing-for-user-engagement-in-medical-technologies---a-framework-people-want-to-use
[i] Fleming, D. R., Jacober, S. J.,Vandenberg,M. A., Fitzgerald, J. T., & Grunberger, G. (1997). The Safety of InjectingInsulin Through Clothing. Diabetes Care, 20(3),244–247. https://doi.org/10.2337/diacare.20.3.244
[i]cdestyni. (2025, February 4). I am soscared to take my first shot because I can’t see the needle. Ozempic needles Ican see so I have control. I have afear of needles so I’m having major anxiety.[Online forum post]. Reddit.https://www.reddit.com/r/Mounjaro/comments/17q64t6/is_it_just_me_or_is_the_peninjector_much_worse/
[ii]Deci, E. L., & Ryan, R. M. (2000). The“What” and “Why” of Goal Pursuits: Human Needs and the Self-Determination ofBehavior. Psychological Inquiry,11(4), 227–268.
[ii]Gleason, P. P., Urick, B. Y., Marshall, L.Z., Friedlander, N., Qiu, Y., &Leslie, R. S. (2024). Real-world persistenceand adherence to glucagon-likepeptide-1 receptor agonists among obesecommercially insured adults without diabetes. Journal of Managed Care &Specialty Pharmacy, 30(8),860–867. https://doi.org/10.18553/jmcp.2024.23332
[iii]Jackson, C., Eliasson, L., Barber, N.,& Weinman, J. (2014). Applying COM-Bto medication adherence: A suggestedframework for research and interventions. The European Health Psychologist,16(1), 7–17.
[iv]Lock, D. (2023, September 20) Design foradherence: a model for predicting and improving medication adherence. TTPInsights. https://www.ttp.com/insights/design-for-adherence-a-model-for-predicting-and-improving-medication-adherence
[i]Palanca, A., Ampudia-Blasco, F. J.,Calderón, J. M., Sauri, I.,Martinez-Hervás, S., Trillo, J. L., Redón, J., &Real, J. T. (2023).Real-World Evaluation of GLP-1 Receptor Agonist TherapyPersistence, Adherence and Therapeutic Inertia Among Obese Adults with Type 2Diabetes. Diabetes Therapy, 14(4), 723–736. https://doi.org/10.1007/s13300-023-01382-9
[i]the_union_organizer. (2025, February 4). “Idid 10 my first shot, then 12. I just now gave myself 15 for week 3. If allgoes well I’ll up it to 20 next week. I’m impatient and this is too expensiveto be overly cautious.” [Online forum post]. Reddit.
[ii]Center for Drug Evaluation and Research.(2024, December 18). FDA’s Concerns with Unapproved GLP-1 Drugs Used forWeight Loss. FDA; FDA.https://www.fda.gov/drugs/postmarket-drug-safety-information-patients-and-providers/fdas-concerns-unapproved-glp-1-drugs-used-weight-loss
[iii] Pfannkuche, A., Alhajjar, A., Ming,A.,Walter, I., Piehler, C., & Mertens, P. R. (2020). Prevalence and riskfactors of diabetic peripheral neuropathy in a diabetics cohort: Register initiative“diabetes and nerves.” Endocrine and Metabolic Science, 1(1),100053. https://doi.org/10.1016/j.endmts.2020.100053
[iv]Norman, Donald A. (2004) EmotionalDesign: why we love (or hate) everyday things. Basic Books.
[v]Kurosu, M., Kashimura, K. (1995). Apparentusability vs. Inherent usability. on Human factors in computing systems - CHI'95. ACM. pp.292–293.
[vi]O’Brien, K., Venn, B. J., Perry, T.,Green, T. J., Aitken, W., Bradshaw, A.,& Thomson, R. (2007). Reasons forwanting to lose weight: Different strokes for different folks. EatingBehaviors, 8(1), 132–135.https://doi.org/10.1016/j.eatbeh.2006.01.004
