A FEW PROGESTOGENS AND RISK OF DVT
levonorgestrel: 4x more risk than not using the pill (safest of them all)
gestodene: 5.6x more risk
desogestrel: 7.3x
cyproterone acetate: 6.8x
drospirenone: 6.3x
http://www.medscape.com/viewarticle/707437?src=mpnews&spon=16&uac=89474MT
UPDATE 9/2010: Yaz causes 64% more clots.