Insulin pen needles are intended for single use only but it is known that a significant proportion of people with diabetes do re-use needles.
Insulin Pen Needles
Reusing Insulin Pen Needles - Risks Involved & Lipohypertrophy
Owen Mumford
Insulin Pen: Types, Purposes, and How to Use
A Coloured Pen Needle Education System Improves Insulin Site Rotation Habits: Results of a Randomized Study
Gap in Injection Technique and Needle Reuse for Diabetics
Humalog Cartridge: What You Should Know - GoodRx
Forum for Injection Technique (FIT), India: The Indian recommendations 2.0, for best practice in Insulin Injection Technique, 2015 – topic of research paper in Clinical medicine. Download scholarly article PDF and read
5 Expert Tips on Injecting Insulin - Diabetes Qualified