Do doctors use the same chemicals for the flu shots?

If your question is asking if licensed US doctors who give flu shots use the same vaccine as is used by the public health organizations and other sources of flu shots, the answer is yes. The only vaccines that any health care professional can administer to you for the flu are the ones that have been approved by the Food and Drug Administration (FDA). Doctors get the vaccine from the same sources as all other providers of vaccinations. The vaccine ingredients are the same.

If your question is asking if the US doctors who personally take a flu shot use the same vaccines as everyone else, that answer is also yes.