Has anyone experienced their heart resting rate falling (I use Fitbit 24h measurements)? I'm on a variable dose but mostly take 100mcg, reduce it by 12.5 if I suspect I may be getting overdosed as I'm very sensitive to dose changes. The only 'hyperlike' symptoms I've experienced were high/low heart rate fluctuations with anxious feeling through the night - this happened a few times and I interpreted it as my dose being too high (suspect adrenal fatigue is involved but just guessing). I'm feeling quite hypo at the moment with tiredness, malaise and lightheadedness. Reducing to 88.7mcg a few days didn't make it any better so I've been on 100mcg 6 days running but my resting heart rate has been declining and today it is 50, down from 56 on Sunday. Could this be that 100mcg is too high after all? Or, if this is the adrenals, what should I do with my dosing? Any experience or advice will be great.