What are the security rules for liquids and medication?

Airport security rules are set by TSA and by the authorities in the countries you travel through, and they do change, so it’s worth checking tsa.gov before you fly. As a general guide, liquids in your carry-on need to be in containers of 3.4 ounces (100 ml) or less, together in a single quart-sized clear bag. Medications are treated more flexibly than other liquids and are generally allowed in larger quantities, but pack them in your carry-on rather than your checked bag, keep them in their original labeled containers, and allow a little extra time at security in case they need to be inspected. If you’re traveling with medical equipment, see “Can I bring my CPAP machine, and where do I get distilled water?”