No, you cannot bring a full-size tube of toothpaste (typically 4 oz or larger) in your carry-on luggage because it is classified as a "gel or paste" under the TSA's 3-1-1 rule. To pass through security, any paste must be in a container of 3.4 ounces (100ml) or less and must fit inside a single, quart-sized, clear resealable plastic bag. Most standard-size toothpastes found in grocery stores are 5 or 6 ounces, which will be confiscated at the checkpoint if found. If you absolutely need a full-size tube for your trip, you must pack it in your checked baggage, where there are no size restrictions for toiletries. Alternatively, many travelers in 2026 have switched to "toothpaste tablets," which are solid and therefore exempt from the liquid/gel restrictions, allowing you to carry a larger supply in your cabin bag without any issues at security.