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.
Passengers flying on international flights carrying $10,000 or more in cash must declare the cash amount to the Customs and Border Patrol and fill out the appropriate form. You are allowed to carry any amount of cash you wish, but it must be recorded on an official document.