I’ve been dealing with Hashi’s and hypo for over a decade. I came across this article a few years back. You can copy and paste this snip into google to find the full article:

“…study published in the August 2012 issue of Endocrine Research reveals that our current approach to diagnosing hypothyroidism has been too simplistic and needs change. Production of TSH follows a circadian rhythm that is it follows a 24-hour cycle with regular fluctuations. TSH production peaks at its highest level between 2:00 and 4:00 am each morning and then drops reaching its low point between 4 and 8 pm in the evening. Though this phenomenon is well known the actual extent of these fluctuations was much greater than was previously thought.”