text: Drospirenone, also known as 1,2-dihydrospirorenone or as 17β-hydroxy-6β,7β:15β,16β-dimethylene-3-oxo-17α-pregn-4-ene-21-carboxylic acid, γ-lactone, is a synthetic steroidal 17α-spirolactone, or more simply a spirolactone. It is an analogue of other spirolactones like spironolactone, canrenone, and spirorenone. Drospirenone differs structurally from spironolactone only in that the C7α acetyl thio substitution of spironolactone has been removed and two methylene groups have been substituted in at the C6β–7β and C15β–16β positions.
  Spirolactones like drospirenone and spironolactone are derivatives of progesterone, which likewise has progestogenic and antimineralocorticoid activity. The loss of the C7α acetylthio group of spironolactone, a compound with negligible progestogenic activity, appears to be involved in the restoration of progestogenic activity in drospirenone, as SC-5233, the analogue of spironolactone without a C7α substitution, has potent progestogenic activity similarly to drospirenone.