All passenger items must undergo security screening. It is recommended that medication be clearly labeled to facilitate the screening process. You may bring medically necessary liquids, medications and creams in excess of 3.4 ounces or 100 milliliters in your carry-on bag.

While there is no federal law in the U.S. requiring you to keep prescription medication in its original, labeled bottle for domestic travel, it is highly discouraged for international flights and security screenings. Security agencies like the TSA in 2026 do not require labels for pills in carry-on bags, but unlabeled pills may lead to additional screening, delays, or questioning if an officer cannot identify the substance. For international travel, many countries (such as Japan or those in the EU) have very strict laws; traveling with unlabeled controlled substances can lead to confiscation or even legal trouble. The "pro" strategy is to always keep medications in their original pharmacy containers with the prescription label intact, or at least carry a digital copy of the prescription and a doctor's letter. For liquid medications exceeding 100ml, a label or prescription is often mandatory to qualify for a security exemption. Keeping labels intact ensures that if you have a medical emergency in flight, the crew or medical volunteers can quickly identify your treatments and provide the correct care.