I see that you are in america.. yes here in america powder substances are removed and not returned. its part of the crack down on drugs and terrorisn laws in the USA since 9\11. usually when someone is entering a hospital treatment providers let their clients know you can take clothing, no powders, no sharp objects, no drugs no alcohol....talk with your treatment providers they can help you get a list of whats allowed and what isnt when you are hospitalized.