I know this is an old thread but there is discussion about the placing of Estradot patches so I'm just posting some info I found as there have been questions about it:
This is the product release info:
"Administration
Patch Application
The physician should discuss the most appropriate placement of the patch with the patient. Immediately after removal of a patch from the pouch and removal of the protective liner, the adhesive side of the ESTRADOT® patch should be placed on a clean, dry area of intact skin. The area selected should not be oily, damaged or irritated, and not exposed to the sun. The site selected should also be one at which little wrinkling of the skin occurs during movement of the body, preferably the buttocks, lower abdomen or hip. The patch may also be placed on the side or lower back. The patch should be placed consistently on the same area of the body with each application (i.e., either the buttocks, lower abdomen, hip, side or lower back). Experience to date has shown that less irritation of the skin occurs on the buttocks than on other sites of application. Therefore, it is advisable to apply ESTRADOT® to the buttocks. The waistline should be avoided, since tight clothing may dislodge the patch. The patch should be pressed firmly in place with the palm of the hand, making sure there is good contact, especially around the edges. In the event that a patch should fall off, it can be reapplied. If it fails to adhere then a new patch may be applied. In either case, the original treatment schedule should be continued. Patches should not be applied to the same skin site twice in succession.
ESTRADOT® must not never be applied to, or near, the breasts to avoid potentially harmful effects on the breast tissue."
So - they discuss irritation, likelihood of dislodging the patch, and condition of skin - rather than absorption per se. I think it's important to find a site that works for these first and then if absorption is insufficient (but no skin irritation, it stays on etc) then a higher dose would be appropriate rather than changing to somewhere it might come unstuck, or the skin is wrinkly, or might irritate more or come into contact with rubbing of clothes.
The product info on Estradot specifies "lower abdomen below the waistline" but by this I read as anywhere on the trunk below the waist back front or side, rather than just the front.
Haven't time to look for any more info atm ...
Hurdity x