You can take lotion on a plane in containers that are 3.4 ounces (100 milliliters) or smaller in your carry-on baggage. All such liquid containers must fit inside one quart-sized (approximately 1 liter) clear, resealable plastic bag, and each passenger is limited to one such bag. Larger containers of lotion must be placed in checked baggage. Exceptions are made for essential medications and baby food, which can exceed the 100 ml limit if necessary and properly declared at security

. In summary:

• Maximum container size for lotion in carry-on: 3.4 oz (100 ml)
• All containers must fit in one clear quart-sized bag
• Only one quart-sized bag allowed per passenger
• Larger containers must go in checked luggage
• Exceptions for medications and baby food with documentation

This rule applies broadly in the US, Europe, and many other regions