Should you wipe the vial stopper every time?

Yes. Wipe the rubber top before every needle goes in, including on a vial you opened yesterday. Care of the shot spot and the vial is one of the topics the expert guidance on insulin shots covers directly. Wiping only once when you first open it is a myth, not a proven shortcut. Poking the top again and again can also shave tiny bits of rubber into the liquid. That risk is lower with a fine insulin needle than with a big one, but it is not zero. This is not a dose or a protocol. Full walkthrough at /injecting.

Full injecting guide: sites, needles, rotation, safety

Educational use only. This database summarizes published research and is not medical advice. Where a dose appears it is a record of what a trial or clinic ran, or what people describe doing, with its source attached. Nothing here is a recommendation for personal use.

Part of injecting: sites, needles and safety. Subcutaneous vs intramuscular, site rotation, lipohypertrophy, needle length and gauge, vial hygiene at injection time, travel syringes, scar tissue, and when to stop and see a clinician. Full walkthrough at /injecting.