I've tried that wgwhen traveling and have not been successful. YMMV. They will turn up the power on the radiation until they can see through the bag. If they can't see, then they will pull it off the line to search. When they search it and see the pills, they will ask for a Dr scriipt explaining why they can't be irradiated. If you don't have one, then they will put them in a basket and run them through the machine. If you try to explain that they are supplements and the radiation will harm them, then they will give you the speech about how it doesn't effect anything (same propaganda the manufacturer spews to avoid product liability and sell the machines). Now they have those backscatter xray devices that irradiate your entire body.
I hope your experience is different from mine. I traveled domestically, but I'm not sure that makes a difference. I ended up shipping things to my destination (UPS only as all other irradiate) and taking a train whenever possible. Please let us know what your experience is as it would be helpful to others. I think the airport you fly out of also makes a difference.