Typically, first aid kits are over-the-counter products and anyone can purchase them - in fact, many use the flexible spending accounts to purchase with tax benefits (just make sure they contain bandages to qualify!)

Furthermore, many will "step it up" to a first aid cabinet, an ems bag,  trauma kit or first responder pack to be really prepared... however, there are some restrictions one a few "medical kits". Some States won't allow sale of kits containing invasive devices (like sutures and syringes) except to licensed medial personnel...

Adventure Medical Suture/Syringe Medic Emergency First Aid Pack

Which states prohibit the sale of certain medical kits containing syringes?

The following states prohibit the sale of the Suture & Syringe content Medical Kits:

Alabama, California, Washington DC, Delaware, Georgia, Hawaii, Nevada, New York, Oklahoma, Oregon, Pennsylvania, Rhode Island, South Carolina, and Virginia.