No. Needles become dull after a single use, making subsequent injections more painful and increasing the risk of tissue damage. Reused needles also carry infection risk even when only used by you—bacteria from your skin can colonize the needle and be introduced deeper into tissue. Insulin syringes are inexpensive (often under $0.15 each). Use a fresh syringe and needle every time. Dispose of sharps in a proper sharps container, not loose in the trash.