1. Reusable insulin pen: after the refill is used up, replace the refill and use it again. The insulin pen can be used for many years, even for life. At present, we can buy this insulin pen in China.

2. Disposable insulin pen: some insulin pens are disposable. When they are used up, throw them away together with the core and replace them with new ones. This kind of insulin pen is simple and hygienic. At present, there are few such insulin pens in China.