Hello DeniseT
Transdermal means using patches or gel. You stick the patches onto your skin, a bit like nicotine patches and these are changed every 3 to 4 days. The gel is dispensed from a pump action container and you rub it onto your body every day. With these methods the hormones are absorbed through the skin and into the blood stream meaning they do not pass through the liver as a tablet would be.
I think I've got all that right (I'm relying on post meno memory here lol).
Wishing you well.
K.