Estradiol (medication)
Estradiol is available in a variety of different formulations, including oral, intranasal, transdermal/topical, vaginal, injectable, and implantable preparations. An ester may be attached to one or both of the hydroxyl groups of estradiol to improve its oral bioavailability and/or duration of action with injection. Such modifications give rise to forms such as estradiol acetate (oral and vaginal), estradiol valerate (oral and injectable), estradiol cypionate (injectable), estradiol benzoate (injectable), estradiol undecylate (injectable), and polyestradiol phosphate (injectable; a polymerized ester of estradiol), which are all prodrugs of estradiol.
Desogestrel
Desogestrel is available widely throughout the world, including in the United States, Canada, the United Kingdom, Ireland, many other European countries, Australia, New Zealand, South Africa, Latin America, South, East, and Southeast Asia, and elsewhere in the world. In the United States, it is available only in combination with ethinylestradiol as a combined oral contraceptive; it is not available alone and is not approved for any other indications in this country.