Estradiol (medication)
Estradiol is also available in the U.S. in combination with progestogens for the treatment of menopausal symptoms and as a combined hormonal contraceptive:Estradiol and estradiol esters are also available in custom preparations from compounding pharmacies in the U.S. This includes subcutaneous pellet implants, which are not available in the United States as FDA-approved pharmaceutical drugs. In addition, topical creams that contain estradiol are generally regulated as cosmetics rather than as drugs in the U.S. and hence are also sold over-the-counter and may be purchased without a prescription on the Internet.
Pharmacokinetics of estradiol
Estradiol has been studied and used by intranasal administration. It was available as a cyclodextrin-containing nasal spray under the brand name Aerodiol in some countries, although this specific product was discontinued in 2007. The product was administered once per day as one 150-μg spray in each nostril (300 μg/day total). Intranasal estradiol has pharmacokinetics similar to those of sublingual and intravenous administration of estradiol, including a sharp peak and then rapid decline in estradiol levels. Despite the relatively short duration of intranasal estradiol, it has similar effectiveness to other, longer-lasting routes of administration in terms of relief of menopausal symptoms like hot flashes.