Improving Patient Outcomes Through Pen Needle Design and Insulin Injection Technique Education

This article and FITTER Forward are sponsored by embecta™.

INTRODUCTION

Insulin therapy is essential for many individuals with diabetes and is among the most effective approaches to achieving glycemic targets.¹ Optimal control, however, depends not only on pharmacologic efficacy but also on proper insulin injection technique.¹ Despite advances in insulin formulations and delivery devices, suboptimal injection technique continues to impact patient outcomes.^1,2

The global expert consensus FITTER (Forum for Injection Therapy and Technique Expert Recommendations) Forward was published in the April 2025 issue of Mayo Clinic Proceedings and subsequently mentioned in the American Diabetes Association’s (ADA) Standards of Care in Diabetes–2026.^1,3

The FITTER Forward authors emphasize health care provider education as critical to improving injection practices and patient experience.¹ Parallel to this educational focus, engineering advances in pen needle design have demonstrated improved patient experience and can help deliver insulin to the subcutaneous (SC) tissue.¹ Specifically, needle innovation and design may reduce pain, help ensure consistent insulin absorption, and promote greater patient comfort and confidence in the administration of insulin.^1,3-7

THE ROLE OF INJECTION TECHNIQUE AND EDUCATION

Injection technique errors are widespread.¹ In 1 survey, all participants reported making at least 1 injection technique error.⁸ Such errors can increase the risk of pain and contribute to the development of a common skin complication, lipohypertrophy.^1-3,7 Lipohypertrophy consists of enlarged adipocytes that are typically presented as lumps at injection sites.¹ Lipohypertrophy is associated with greater insulin requirements and episodes of unexplained hypoglycemia.^1,2,7 Needle reuse and poor site rotation have been identified as risk factors contributing to the development of lipohypertrophy.^1,2,7

FITTER Forward identified over a decade of evidence demonstrating that structured injection technique education can improve glycemic outcomes, including reductions in higher hemoglobin A_1c (HbA_1c), and decrease the occurrence of skin complications such as lipohypertrophy.¹

Structured injection-technique education programs—emphasizing correct site selection, rotation, single use of needles, and safe disposal—can help reduce the risk of complications.¹ FITTER Forward reinforces standardized, routine training as an essential component of diabetes management.¹

RECOMMENDED PEN NEEDLE TECHNOLOGY AND IMPACT ON INJECTION EXPERIENCE

Alongside injection technique, FITTER Forward experts recognized that specific device characteristics can help improve the injection experience and how insulin is administered.¹ Four key features that are recommended per available evidence include a contoured needle base, 4-mm × 32-gauge needle, ultra-thin wall technology, and a 5-bevel sharpened tip (Figure 1). ^1,9

A contoured needle base provides a larger skin-contact surface that evenly distributes pressure and compensates for excess injection force, minimizing indentation, bruising, and the risk of inadvertent intramuscular (IM) injection.^1,4,5 A contoured needle base with a 4-mm needle helps to maintain a more consistent target injection depth, even when patients inject with too much force.⁴ In a mathematical model, the contoured base reduced IM injection probability 2- to 8-fold versus posted designs across multiple injection sites.⁴ Consistent SC tissue delivery of insulin translates into more predictable absorption.^1,7 Furthermore, pen needles with a contoured base have reports of improved ability to hold the pen securely against the skin without wobbling during an injection.⁵

A 4-mm needle length is recommended for all patients, as this length is long enough to traverse the skin and short enough to help avoid IM injection.^1,10 An ultrasound study identified that adult skin thickness averages 2.0 to 2.5 mm regardless of age, sex, or body mass index, supporting a 4-mm length as safe and effective for achieving consistent SC delivery.^1,7,10 With IM injection, there is a greater chance of pain, bleeding, bruising, and erratic insulin absorption.^1,3,7

NANO™ 2ND GEN PEN NEEDLES ALIGN TO EXPERT RECOMMENDATIONS

Needle thickness, defined by gauge, is another defining feature of a pen needle.¹ The gauge number and the outer needle diameter share an inverse relationship—as the gauge number increases, the outer diameter decreases.¹ Needles with a higher gauge are associated with less pain.¹ Experts recommend a 32-gauge needle, as current evidence suggests that 32-gauge reduces pain without being too fragile.¹

Needle sharpness is determined by the geometry of the tip and by avoiding needle reuse.¹ More bevels, or cuts in the tip, can improve the sharpness.¹ A 5-bevel sharpened tip is recommended, as it enhances penetration force and can lead to improved perceived pain compared with traditional 3-bevel designs.^1,11,12

An ultra-thin wall, defined by ISO as the thinnest allowable wall specification, improves flow dynamics by widening the internal diameter without increasing external gauge.^1,13 This design reduces the force required to press the injection dose button of the pen and the time needed to administer an insulin dose, resulting in faster insulin delivery.^1,6

Another element is the needle’s silicone coating. Lubrication of the steel surface of the needle is commonplace for hypodermic needles, as this may help reduce the force required for skin penetration and reduce drag resistance.^1,12 The lubrication on new needles contributes to a smoother injection through the skin, ultimately supporting overall injection comfort and consistency.¹ With reuse, however, both lubrication and tip sharpness can be impacted, which is a reason why pen needles should not be reused.¹

These refinements demonstrate how advanced pen needle design and engineering can support more consistent SC insulin delivery, helping to minimize the risk of an accidental IM injection and contribute to improved patient outcomes, including a more comfortable, less painful injection experience.^1,7

Nano™ 2nd Gen Pen Needles incorporate key features that align with the FITTER Forward expert recommendations, including a contoured needle base, 4-mm × 32-gauge needle, 5-bevel sharpened tip, and ultra-thin wall technology (Figure 2).^1,9 The clinical impact of these innovations in 1 device was supported in a multicenter, randomized, open-label crossover trial of 226 patients with diabetes; Nano™ 2nd Gen Pen Needles were overall rated superior in preference, comfort, and ease of use compared with other pen needles.⁵ Collectively, these findings underscore the value of integrating evidence-based design features into a single device to support more consistent and comfortable insulin delivery.^1,4,5

PRACTICAL IMPLICATIONS FOR PHARMACISTS AND CLINICIANS

Pharmacists play an essential role in reinforcing proper injection practices to optimize patient outcomes. Education should emphasize site rotation to prevent lipohypertrophy and maintain consistent insulin absorption.^1,7,14 Reinforcing the single-use concept and safe disposal of pen needles helps prevent infection, needle deformation, and dosing errors associated with reuse.^1,7,14 Pharmacists should also help to ensure that pen needle supplies are refilled concurrently with insulin prescriptions to sustain 1-needle-per-injection use and avoid reuse due to limited availability.¹ Additionally, pharmacists can assist with device matching, guiding patients toward a contoured base, 4-mm × 32-gauge pen needle suited to individual preferences and therapeutic needs to promote comfort and safety.^1,7 Implementing FITTER Forward recommendations along with proper injection technique education and innovations such as the Nano™ 2nd Gen Pen Needle can enhance overall patient satisfaction, minimize discomfort, and help promote consistent glycemic control in daily diabetes management.^1,4,5

CONCLUSION

Safe and consistent insulin delivery depends on both proper technique and device design. Nano™ 2nd Gen Pen Needles exemplify how integrating a contoured base, 4-mm × 32-gauge needle length, 5-bevel tip, and ultra-thin-wall technology can enhance the overall patient experience and provide a more consistent 4-mm injection depth.^1,4,5 The addition of structured injection technique education can contribute to improved glycemic outcomes.¹

Health care professionals, particularly pharmacists, play a critical role in reinforcing education and can help ensure patients have appropriate supplies and training.¹ Aligning clinical education with technological innovation, as advocated by the FITTER Forward recommendations, fosters safer, more consistent, and patient-centered insulin therapy.¹ Through continuous education and adoption of advanced injection devices, clinicians can help transform routine injections into more effective, confident, and comfortable experiences.

REFERENCES

1. Klonoff DC, Berard L, Franco DR, et al. Advance Insulin Injection Technique and Education With FITTER Forward Expert Recommendations. Mayo Clin Proc. 2025;100(4):682-699. doi:10.1016/j.mayocp.2025.01.004
2. Frid AH, Hirsch LJ, Menchior AR, Morel DR, Strauss KW. Worldwide Injection Technique Questionnaire Study: Population Parameters and Injection Practices. Mayo Clin Proc. 2016;91(9):1212-1223. doi:10.1016/j.mayocp.2016.06.011
3. American Diabetes Association Professional Practice Committee for Diabetes.* 9. Pharmacologic Approaches to Glycemic Treatment: Standards of Care in Diabetes-2026. Diabetes Care. 2026;49(suppl 1):S183-S215. ​
   doi:10.2337/dc26-S009
4. Rini C, Roberts BC, Morel D, Klug R, Selvage B, Pettis RJ. Evaluating the Impact of Human Factors and Pen Needle Design on Insulin Pen Injection.
   J Diabetes Sci Technol. 2019;13(3):533-545. doi:10.1177/1932296819836987
5. Whooley S, Briskin T, Gibney MA, Blank LR, Berube J, Pflug BK. Evaluating the User Performance and Experience with a Re-Engineered 4 mm × 32G Pen Needle: A Randomized Trial with Similar Length/Gauge Needles. Diabetes Ther. 2019;10(2):697-712. doi:10.1007/s13300-019-0585-7
6. Aronson R, Gibney MA, Oza K, Bérubé J, Kassler-Taub K, Hirsch L. Insulin pen needles: effects of extra-thin wall needle technology on preference, confidence, and other patient ratings. Clin Ther. 2013;35(7):923-933.e4. doi:10.1016/j.clinthera.2013.05.020
7. Frid AH, Kreugel G, Grassi G, et al. New Insulin Delivery Recommendations. Mayo Clin Proc. 2016;91(9):1231-1255. doi:10.1016/j.mayocp.2016.06.010
8. Bari B, Corbeil MA, Farooqui H, et al. Insulin injection practices in a population of Canadians with diabetes: an observational study. Diabetes Ther. 2020;11(11):2595-2609.
9. Nano™ 2nd Gen Pen Needles. Embecta website. https://www.embecta.com/en-us/pen-needles/nano-2nd-gen?utm_source=goredirect&utm_medium=catch_all_channels&utm_campaign=gotocorp_redirect_catchall. Accessed October 24, 2025.
10. Gibney MA, Arce CH, Byron KJ, Hirsch LJ. Skin and subcutaneous adipose layer thickness in adults with diabetes at sites used for insulin injections: implications for needle length recommendations. Curr Med Res Opin. 2010;26(6):1519-1530. doi:10.1185/03007995.2010.481203
11. Heinemann L, Nguyen T, Bailey TS, et al. Needle Technology for Insulin Administration: A Century of Innovation. J Diabetes Sci Technol. 2023;17(2):449-457. doi:10.1177/19322968211059564
12. Hirsch L, Gibney M, Berube J, Manocchio J. Impact of a modified needle tip geometry on penetration force as well as acceptability, preference, and perceived pain in subjects with diabetes. J Diabetes Sci Technol. 2012;6(2):328-335. doi:10.1177/193229681200600216
13. International Organization for Standardization. ISO 9626:2016—Stainless steel needle tubing for the manufacture of medical devices—Requirements and test methods. 2nd ed. International Organization for Standardization; 2016.
14. Frid AH, Hirsch LJ, Menchior AR, Morel DR, Strauss KW. Worldwide Injection Technique Questionnaire Study: Injecting Complications and the Role of the Professional. Mayo Clin Proc. 2016;91(9):1224-1230. doi:10.1016/j.mayocp.2016.06.012