I Have A Question In Regards To Thyroid Regulating. My

I have a question in regards to thyroid regulating. My mother had her thyroid removed 3 years ago and has taken the same brand of hormones for 3years now. She is seeing a PCP regularly but isn't getting anywhere, she has trouble with concentration, memory and functioning she can always tell when her hormones are off balance. She cannot work or keep certain jobs because of this. I think seeing an endocrinologist is the next for her? And also are there different types hormones she can take for thyroid?