Do prescription medicines need to be in the original containers in carry-on luggage in domestic flights, or can I put my meds in a pill box?

https://www.tsa.gov/blog/2014/09/05/tsa-travel-tips-traveling-medication

As long as they go through the X-Ray machine, the TSA does not care about how you sort your meds. Your good.

I put mine all mixed up in 1 bottle, I put in my carry on. Just make sure if they go through your bag that TSA didn't steal them. That has happened to me.

As long as they go to through the X-ray 😀