Could transdermal estradiol + progesterone be a safer postmenopausal HRT? A review.
In conclusion, while all types of hormone replacement therapies are
safe and effective and confer significant benefits in the long-term
when initiated in young postmenopausal women, in specific clinical
settings the choice of the transdermal route of administration of
estrogens and the use of natural progesterone might offer significant
benefits and added safety.
Maturitas. 2008 Jul-Aug;60(3-4):185-201.