Not sure, I never read anything about GHRP's or GHRH's causing thyroid hormone changes. How did you hear about this? Any links?

Or are you just trying to guess based on elevated HGH levels caused by peptides? ... wish I knew an answer for ya.
Would a low dose help supplement levels? Or does thyroid hormones act like others and it shuts you off completely at any dose? (Sorry don't know too much about T3/T4/Synthroid, etc)