Do not Reuse Needles
The harm you can cause yourself by reusing a needle is much greater than any convenience or cost savings. The tips of needles may become damaged after just one injection. Even though you can’t see this damage it’s still there – and it may become worse each time you reuse. There are a lot of good reasons not to reuse syringe or pen needles:
The tip of a reused needle can be weakened to the point where it breaks off and gets stuck under your skin.
A reused needle doesn’t inject as easily or as cleanly as a new one and can cause pain, bleeding, and bruising.
Studies have shown that there’s a link between needle reuse and the appearance of lumps of fatty tissue that can form at an injection site (lipodystrophy).
Thin, fine, high-quality needles are designed to be used one time only.