Yes, you can put powder in both your checked suitcase and your carry-on bag, but there are specific TSA "Powder Rules" to follow for your carry-on. If you are carrying more than 12 ounces (350ml) of a powder-like substance (roughly the size of a soda can)—such as protein powder, baby powder, or cosmetics—in your carry-on, you must remove it from your bag at the security checkpoint for separate X-ray screening. TSA officers may need to open the container for additional testing to ensure it is not an explosive or a prohibited substance. To avoid delays in 2026, it is highly recommended to pack large quantities of powder in your checked luggage instead, where there are no specific volume restrictions. If you must carry it with you, ensure it is in its original, labeled container. This rule was implemented globally in 2018 following security threats involving powdered substances, so if you are traveling with large bags of flour, sugar, or supplements, be prepared for a bit of extra scrutiny during the screening process.