Yes, you can pack mascara in your carry-on bag, but it is subject to the TSA 3-1-1 liquids rule (or the local equivalent in your country). Even though it is a tube, security agencies classify mascara as a "liquid, gel, or aerosol" because of its semi-fluid consistency. This means the tube must be 3.4 ounces (100ml) or smaller, and it should be placed inside your single, clear, quart-sized "liquids bag" alongside your shampoo and toothpaste. Most standard mascaras are well under this limit, typically ranging from 0.2 to 0.4 ounces, so they are perfectly safe for cabin travel. If you are flying through an airport equipped with newer CT scanners (which are becoming more common in 2026), you may not even need to remove your liquids bag from your suitcase, but the 100ml container rule still applies. If you prefer not to worry about the liquids bag at all, you can opt for "solid" cake mascara, which is exempt from these volume restrictions.