GHB (gamma-hydroxybutyrate) is produced naturally in the human body in very small amounts. When taken as a recreational drug, and especially when taken in combination with alcohol or other drugs, GHB can be extremely dangerous. GHB is a central nervous system depressant.
International flights always allow carry-on luggage, but each airline has its own restrictions as to quantity, size and weight. Some international carry-on policies restrict bag weights to 11 lbs. or less, while domestic flights rarely have a weight limit.
Check your bags with no service charges. You can check up to two standard-sized bags free of charge when traveling in United First. Premier Access also includes priority baggage handling, so your checked bags receive special attention and are among the first to arrive at baggage claim at your destination.