Doctors are regulated in all sorts of ways. They may not practice law etc. They are licensed by the state to be doctors and the state can tell them what that license allows them to do.
You may not like it that doctors are licensed, but reasonable people see the need. Only an anarchist would think doctors shouldn't be regulated.
Doctor does something you don't like that harms no one. You want the gov'ment to come in and tell the doctor what he can and cannot say. That is wrong as the government has no moral right to do that - the doctor and the patient are not the government's property.