Proestrogens, such as mestranol
, are known to require metabolic transformation to exert estrogenic effects (Schmider et al.
To help improve the reliability of the test, 100 [micro]g of mestranol
is also given daily to stabilize estrogen levels during the testing interval.
In vitro and in vivo genotoxicity evaluation of hormonal drugs V, mestranol
. Mutation Research, 322: 173-183.
Of these, 4-nonylphenol (linear) was inactive in all 3 ToxCast[TM] in vitro binding assays (but active in 10 of 11 of the remaining agonist-mode assays), 4-dodecylphenol was inactive in 2 of 3 assays (bovine and mouse), and mestranol
was inactive in only 1 (mouse) of 3 ToxCast[TM] assays (see Figure 4).
All combination OCs contain either EE or mestranol
. However, a variety of progestins have come into use.
 The use of oral contraceptives containing less than 100 [microgram] of either ethinyl estradiol or mestranol
has approximately one third the risk of thromboembolism that using those products containing 100 [microgram] or more of the estrogen component has.
Preparation of 9-alpha, 11-xi-tritiated 17-alpha-ethynylestradiol, mestranol
, estradiol-alpha-17-beta, and norethindrone.