While there are a number of different brands and models available, most insulin pens fall into one of two groups: reusable pens and disposable pens.
Before using a reusable pen, you must load it with a cartridge of insulin (sold separately usually in boxes of five cartridges). Cartridges used in the U.S. today hold 150 or 300 units of insulin. Depending on the size of your doses, a cartridge may give you enough insulin to last for several days of injections. When the cartridge is empty, you throw it away and load a new cartridge. With good care, a reusable pen can often be used for several years.
Disposable pens come filled with insulin and are thrown away when they're empty. Most disposable pens used in the U.S. today hold 300 units of insulin and are sold in boxes of five.
Disposable pens are generally more convenient than reusable pens because you don't need to load any cartridges, but they usually cost more to use than reusable pens and cartridges.
Pen brands and models differ from one another in many ways. When choosing a pen, there are many factors to keep in mind, including:
Advantages and Disadvantages
The reasons why some insulin users prefer insulin pens include:
There are also reasons why insulin pens aren't right for all users, including:
Hope this tells you what you wanted to know about pens.