Regarding Spironolactone having estrogenic activity, this is what another study states, contrary to the above study
CLIMACTERIC 2005;8(Suppl 1):3–63
Pharmacology of estrogens and progestogens: influence of different routes of administration
H. Kuhl
Department of Obstetrics and Gynecology, J. W. Goethe University of Frankfurt, Germany
"The chemical structure of drospirenone, which is a derivative of 17a-spirolactone, is similar to that of the aldosterone antagonist spironolactone"
"The antiandrogenic activity of drospirenone is about 30% of that of CPA. It has no estrogenic and no appreciable glucocorticoid activity"
"Besides the natural progesterone, four types of orally active, synthetic progestins are available: the progesterone derivatives, 19-norprogesterone derivatives (Figure 9), 19-nortestosterone derivatives and the spirolactone derivative drospirenone (Figure 10). They all exert progestogenic and – in some tissues - antiestrogenic activities, but differ largely in their hormonal pattern."
Experimental and Clinical Psychopharmacology Copyright 2007 by the American Psychological Association
2007, Vol. 15, No. 5, 427–444
Progesterone: Review of Safety for Clinical Studies
"Others that are derived from progesterone (17 hydroxyprogesterone derivatives), hydroxyprogesterone (19 norprogesterone derivatives), or spironolactone (drospirenone) have been found to exert estrogenic, glucocorticoid, and mineralocorticoid actions (Pluchino et al., 2006)."
This study, on the other hand agrees with the study from the UK.
I need to read some more...
