OK, so I just compared two bottles of Erfa Thyroid:
One with batch no LF04265A (exp 08/17)
one with batch no LF03505A (exp 02/17)
The first batch does not work at all; the second works just fine. Yet, all the pills look the same. There is no visible difference as far as shininess (is that a word?), blotchiness, etc are concerned....all things mentioned by STTM to distinguish "old" Erfa from from the "new"..."new" Erfa was reportedly more shiny, blotchy, etc.
I cannot explain it, but the two batches are very different when it comes to how my body react to them...when it comes to the first, it's like I've taken nothing at all; as for the second batch, I feel completely normal.
So there is a difference. However, what I don't understand is this: if something changed (due to fillers, binders, processing, manufacturing process, etc), why are not all batches different, just some?!