The use of insulin pens has become fairly widespread these days, with most diabetic patients using a pen to administer insulin. Insulin pens are simpler to use and are more convenient and accurate than a vial and a syringe. A pen contains a disposable insulin pen needle, a dial to measure dosage, and a cartridge. With advanced technology, needles have become finer and shorter than ever before, but are still able to deliver insulin effectively. Pen needles are typically coated with a lubricant in order to enable them to smoothly penetrate the skin. The length and thickness of needles for insulin are important considerations while choosing a product for insulin administration. The thickness of a needle is measured using “gauge”. The higher the gauge, the finer or thinner the needle. Pen needles are usually between 4 and 12.7 millimeters (mm) in length. Dispovan pen needles are attached onto the insulin pen by screwing on the tip. The insulin pen needle must be replaced after every injection of insulin. Reusing a pen needle can cause problems like pain, bleeding, bruising, and even lipodystrophy or build-up of lumpy fat tissue.