A number of prodrugs of NET, including norethisterone acetate ( NETA ), norethisterone enanthate ( NETE ), etynodiol diacetate, lynestrenol, and quingestanol acetate, have been marketed as well.
22.
The drug is a relatively weak progestogen, with only about one-tenth of the progestogenic activity of norethisterone, and in relation to this fact, is no longer used in oral contraceptives.
23.
The discovery of the retained and potentiated progestogenic activity of 19-norsteroids like 19-norprogesterone resulted in the synthesis of norethisterone, and in turn, the introduction of the first hormonal contraceptives.
24.
Estradiol undecylate, in combination with norethisterone acetate ( at doses of 5 mg and 50 mg, respectively ), was studied as a combined injectable contraceptive, but ultimately was not marketed for this purpose.
25.
In contrast, the non-halogenated 19-nortestosterone derivatives norgestrel, norethisterone, noretynodrel, and etynodiol diacetate, which are much less potent as progestogens, did not produce such effects at the dosages tested.
26.
It was developed in the 1950s and, along with the testosterone derivatives ethisterone, norethisterone, normethandrone, and norethandrolone and the progesterone derivative hydroxyprogesterone acetate, was one of the first orally active progestogens to be developed.
27.
Treatment with a progestin, norethisterone, reduced her estradiol concentrations to normal levels and decreased the size of her ovaries and the number of ovarian cysts, alleviating her hypothalamic-pituitary-gonadal axis hyperactivity and ovarian pathology.
28.
Dr . Don Catlin, director of the Olympic drug-testing lab at UCLA, said that the active ingredient in most birth-control pills sold in the United States _ norethisterone _ is a close relative of nandrolone.
29.
In regards to the latter, estradiol valerate is available in combination with a progestogen as an combined estradiol-containing oral contraceptive ( with dienogest ) and as a combined injectable contraceptive ( with hydroxyprogesterone caproate or norethisterone enanthate ).
30.
However, it saw relatively little use, which was perhaps due its comparatively low potency relative to a variety of other progestins such as medroxyprogesterone acetate and norethisterone that were introduced around the same time and hence that may have been favored.
