Medication in liquid form is allowed in carry-on bags in excess of 3.4 ounces in reasonable quantities for the flight. You may bring medically necessary liquids, medications and creams in excess of 3.4 ounces or 100 milliliters in your carry-on bag.All medical liquids in containers greater than 3.4 ounces must be removed from your carry-on luggage and declared to TSA. View the most current versions of the laws and regulations governing controlled substances and the official prescription forms in New York State. All prescription medicines are allowed on airplanes, whether in a carry-on or checked bag. Some prescription drugs may be illegal in other countries. You can travel with prescription drugs or medication in both carryon and checked baggage. Report illegal prescription drug sales or suspicious pharmacies on the Internet here. Criminal groups, including drug cartels, are very active across the country.