Pen Needles 101
1. Preferably, use a new needle each time you inject with an insulin pen (a sharp needle is less painful). At least change it daily.
2. To prevent the transmission of diseases, just say no to sharing pen needles with anyone.
3. Needle length varies between 4 mm and 12 mm. The right-size needle helps ensure that insulin doesn't leak out of the injection site, although studies have shown that shorter needles work for most body types. Needle length has less to do with sensation of pain than does needle thickness.
4. A needle's gauge refers to its diameter: The higher the gauge, the thinner the needle. Thicker needles are often better for people who inject large doses of insulin, while thin needles may be less painful for some people.
5. If you're thin, pinching up the skin around the injection site before you insert the needle is a good way to keep the needle from penetrating muscle (you want the insulin to go into the layer of tissue just under the skin).