Definition: An alcohol swab is a small pad soaked in alcohol, used to clean the skin before an injection or the rubber top of a vial or pen before a needle goes through it. Many injection instructions include one, along with the step of letting the spot dry before you inject.
The Ozempic and Wegovy instructions say to clean the injection site with an alcohol wipe and let it dry before injecting. The Tubersol skin test label says the same in general terms: clean the skin with a suitable germicide and let it dry before the needle goes in.
The Mounjaro vial instructions say to pull off the plastic cap, leave the rubber stopper in place, and wipe the stopper with an alcohol swab before drawing up a dose. The Lantus SoloStar instructions say to wipe the pen's rubber seal with an alcohol swab before attaching a new needle.
The Kovaltry instructions, which use a vial adapter, say to clean the rubber stopper with a sterile alcohol swab and to avoid touching the stopper afterwards.
CDC injection safety guidance lists alcohol wipes among the supplies that should be on hand where injections are prepared, so that aseptic technique can be followed.
A multi-dose vial is pierced many times over its life, so the stopper is wiped many times too. Swabs are also a supply that runs out quietly. If you get redness or a lump at a site, logging the site and date with each dose makes it easier to see a pattern and show it to a clinician. See injection site reaction.
Read more on Dose Track: Tracking vials and supplies · Logging injection sites