Sublingual Absorption of Progesterone and Anhydrohydroxyprogesterone

Abstract

Endometrial studies were performed following sublingual application of specially prepared linguets of progesterone and anhydrohydroxypro-gesterone. The dosage for the former in this series was 62.5-250 mg. and for the latter 105-200 mg. The medication was usually administered over a period of 3-10 days. In general, the endometrium with but few exceptions persisted in the estrogenic phase. Mixed, imperfect progestational, or progestational changes were obtained in several instances with the larger dosages. The frequency with which withdrawal bleeding or "the arrest of bleeding according to plan" was obtained suggests effective absorption sublingually of both progesterone and anhydrohydroxy-progesterone and that the dose needed to produce this reaction is much below the level needed to change an estrogenic endometrium to a progestational one. The criticism that proof of sublingual absorption of estradiol, methyl testosterone or anhydrohydroxyprogesterone is not convincing inasmuch as part of these drugs may be swallowed does not hold for progesterone. It is possible, therefore, since progesterone is inactivated after ingestion but is active after sublingual absorption, that the other steroids, may also behave in the same way.