Hi there - I have changed from Estradot (75 mcg cut down to 62.5 mcg) to Estraderm (ditto) and then more recently to Elleste Solo MX (80 mcg cut down to 62.5 mcg). I was recently changed to the Elleste because the Estraderm became difficult to get hold of (through local dispensary via Alliance Healthcare). I'm very happy with these Elleste - but for me changing to Estraderm was a big shock as they are MAHOOSIVE compared with Estradot which are tiny!
The dosage on the patches are such that they are designed to deliver the same amount of estradiol PER DAY irrespective of the total amount listed on the patch, The patches are all different sizes, and have different fillers ( glue etc) and there will have been trials done to determine the average dose so that it is approximately standardised. As always the amount YOU absorb personally will vary depending on many factors like where you apply the patch, how much fat you have on the part of the body where you apply the patch, thickness of skin, what you put on your skin, body temperature, ambient temperature etc.
It is interesting that the Estraderm patch appears to have so much less in total though! Maybe something to do with the overall size?
Hurdity x