I am hypothyroid (around 20 yrs) and was diagnosed with ME/CFS many years afterwards (around 6 yrs ago), though the decline had begun before this. As I had been on T4 only for most of that time I began to get adrenals tested and saw an endo who agreed to let me try T4/T3 combo.
My adrenals were not great, but not dreadful (lowish cortisol but DHEA OK). Curiously I felt worse at the time on T3/T4 combo and stopped after 6 weeks because I felt so fatigued - maybe that was the adrenal issue?
Then I suggested to the endo that I might be allowed to try T3 only, and to my surprise, he and the GP agreed, and that was 2 years ago. My adrenals actually did perk up a bit for a while at the time, but I had them retested recently after Christmas as I knew I had relapsed, and they were back to the not very good, but not dreadful state. I am now trying Pregnenolone to see if that will help the adrenals this time as I have only ever treated it with herbs like liquorice, or I did do Paul Robinson's Circadian rhythm method one year, but didn't like waking myself up at silly times.
I have tried reintroducing some T4 into the equation again (twice last year) but each time my hair seemed to drop out badly, and it actually stopped growing on my legs and under my arms - anyone know why this should be? Maybe I will try again at some point this year once my adrenals are sorted out.
It is very hard with both being hypothyroid AND having ME/CFS to know what is what, though I have tried to do all the right things with diet and supplements to make sure it's all optimal for the thyroid (e.g. B12, Vit D, iron, etc)