I was given a diagnosis of hypothyroidism and put on Synthroid over 20 years ago before I was officially diagnosed with CFS/ME/SEID in 2004. I am still on the meds and it does nothing for the fatigue I feel now. It didn't change how I felt back then either, but I trusted my doctor's diagnosis.

Thyroid meds are not taken for fatigue. They are only taken if a person is dx with hypothyroidism, the first most common sign of which is a TSH blood test with a level of 3 or above. If that happens, other tests are taken to see which meds are needed. Taking thyroid meds when they aren't needed can cause all kinds of havoc.
This I can say from experience because I have Hashimoto's (hypothyroid) and if my meds are even a little too strong I get arrhythmia, lose my hair, get panic attacks... nothing to mess with.

If you are looking for something to give you more energy, some of the supplements taken by folks here are:
B complex with extra B 12 or B12 shots.
D3 (if tests show a low level)
Iron ( if anemic)
D-Ribose - in doses from 500mg to 5000 mg a day
Dietary changes, elimination of carbs, or more carbs, dependent on the person but most of us seemingly do better on less carbs and whole foods.

i went to a holistic specialist in NY. he put me on hydrogen peroxide IVs for a couple months & diagnosed me with hypothyroid. he also put me on armour thyroid 15 mg. but my infectious disease dr & gyno said my blood work for thyroid is fine , but im not too sure. now taking LifeExtension supplement for thyroid from my nutrionist instead.

taking those supplements mentioned above really do help CFS so i am sticking with them.

I actually had the opposite problem in my teenage years. I had hyperthyroidism (overactive thyroid) and had to drink iodine every day..yuck! The other women in my family have hypothyroidism and take thyroid supplements. Fatigue is usually the first symptom they feel when their thyroid meds need to be adjusted. And sometimes they need to increase the dose even tho the blood test results do not show that their thyroid is "clinically" under active. Personally I believe finding the right level is a delicate balancing act. I also believe that endocrinology is the least understood and most neglected of all the health sciences. (except for CFS of course)

My TSH test results vary from year to year (ranging from .7 to 2.3), but my doctor keeps me on the same dosage. Fatigue was the symptom that caused by doctor to check my TSH levels. At that time the TSH score was over 4, maybe even as high as 5.

Some people take t3 for different reasons. Usually fatigue or incomplete response to synthroid, etc. Also prescribed as an add on to antidepressants.

I take 60 mg of armor thyroid. It was prescribed about ten years
ago and has always helped me though I'm having more fatigue now
then I've had in quite a while.
Has anyone taken synthroid after armor? Have
they noticed any difference?

I have hashimoto thyroiditis, so I am on levothyroxine