Metformin decreases circulating androgen and estrogen levels in nondiabetic women with breast cancer.

CONCLUSION: Metformin does not interfere with the production of dehydroepiandrosterone sulfate. Besides, it decreases estradiol levels, basically through the reduction of testosterone. These hormonal changes might have clinical relevance.
PMID: 24267731 [PubMed - in process]

Source: Clinical Breast Cancer - November 29, 2013 Category: Cancer & Oncology Authors: Campagnoli C, Berrino F, Venturelli E, Abbà C, Biglia N, Brucato T, Cogliati P, Danese S, Donadio M, Zito G, Pasanisi P Tags: Clin Breast Cancer Source Type: research