So technically, you can travel with needles in carry on. And as stated, legally they aren’t supposed to be able to ask you about meds. However, I personally wouldn’t risk it going through the scanner and giving them reason. Throw it in checked bags and leave it be. No need to worry there imo. I’ve flown into Nola, Hawaii, and houston with pins and gear. I would just try not to take a brand new vial of anything if you can manage it. Or transfer a couple mL’s into a sterile vial if you only have new ones. All depends how long you’ll be gone and how much you’re pinning.