Regardless of the route of administration, estradiol valerate behaves as a prodrug of estradiol via cleavage by esterases into estradiol and the natural fatty acid valeric acid. This cleavage occurs not only in the liver, but also in the blood and in tissues, and the hydrolysis of estradiol valerate into estradiol and valeric acid is complete regardless of whether the medication is administered orally or parenterally. High levels of circulating estradiol are found after an intravenous injection of estradiol valerate, and this indicates very rapid cleavage of the medication upon entering circulation.