Provera belongs to group of medicines called progestogens and is related to the naturally occurring hormone called progesterone. The active ingredient in Provera is called medoxyprogesterone acetate. Provera tablets are available in a number of strengths 2.5mg, 5mg, 10 mg, 100mg, 200mg & 400mg. The lower doses tend to be used for non-malignant conditions and the higher ones for cancers such as Breast, Uterus or Kidney.