Exemestane is a 3rd generation AI if I remember right. Truthfully, unless you're having a severe outbreak of estrogen and breast sensitivity and need letro since it's the most potent of them all to nuke estrogen and stop nip issues..everyone should be using exem, doesn't wreck your values as bad, and is a suicide inhibitor. There's no reason to use Adex now, and letro isn't needed for daily use for lethargy issues among other things.