Updated from an article originally published in July 2023. For many people managing chronic conditions, injections are part of everyday life. Syringes are used to deliver insulin and other injectable medications, including certain hormone therapies. Even with options such as insulin pens and autoinjectors, vials and syringes remain part of many treatment plans. The device used depends on the medication, available formulations, insurance coverage, cost, and individual preferences. This guide explains syringe sizes, needle types, and how syringes work. It also covers safe injection practices and tips for troubleshooting common challenges, helping you better understand the supplies used for your…