Abstract: A vaginal progesterone suppository is provided in the form of a tablet which delivers biologically effective amounts of progesterone for at least about 48 hours, and blood amounts above basal levels for 72 hours. The tablet is formulated to preferably have a hardness on its edge of 8-13 kg, and disintegrates from its surface to form a milky suspension in 6-8 hours after it is inserted in the vaginal vault. The tablet contains, by weight, about 13-20% progesterone, 65-85% lactose, 2-10% corn starch paste binder, 3-10% corn starch disintegrant, and 0.1-0.9% magnesium stearate as a lubricant. The ratio by weight of progesterone to lactose is preferably 1:6, and the ratio of starch paste binder to starch disintegrant is preferably 1:1. This dosage form is an effective treatment for many progesterone deficiency conditions, and provides enhanced bioavailability.