natural oestrogens `` '' premarin '' '' , ( ayerst , conjugated equine oestrogens ) `` '' harmogen '' '' , ( abbott , piperazine oestrone sulphate ) and `` '' progynova '' '' ( schering , oestradiol valerate ) alone and in combination with proestational agents such as `` '' primolut n '' '' , ( schering , norethisterone ) `` '' neogest '' '' , ( schering , norgestrel ) , `` '' norgeston '' '' , ( schering , levonorgestrel ) , `` '' duphaston '' '' ( duphar , dydrogesterone ) did not have adverse effects on clotting factors .
C0028368
schering ,
C0023566
( schering , le