I didn't realize there was an actual phone # for TSA so I called and she said protein powder in a new sealed bag or individual baggies or however you choose to pack it, is acceptable in your carry on! It is just subject to a possible search.
Been there. Done that.
If you leave it in your bag it looks like a liquid on their screen, weird but true. Now I just take it out and put it with my little baggie of liquids. That way they don't hold you up to search your entire bag.
