Noun
levonorgestrel (uncountable)
(pharmacology) A synthetic progestogen used as an active ingredient in some hormonal contraceptives.
Both copper IUDs and levonorgestrel releasing IUSs may interfere with implantation, although this may not be the primary mechanism of action. Source: Internet
Early treatment with ECPs containing only the progestin levonorgestrel has been show to impair the ovulatory process and luteal function. 83–87 p. 123: Combined emergency contraceptive pills. Source: Internet
To solve the problem of unscheduled bleeding and spotting, the second generation progestins (norgestrol and levonorgestrel) were designed to be significantly more potent and to have longer half-lives than norethisterone-related progestins.. Source: Internet
If taken before ovulation, the high doses of progestogen in levonorgestrel treatments may induce progestogen withdrawal bleeding a few days after the pills are taken. Source: Internet
Progestogens such as norgestrel and levonorgestrel should be avoided due to their androgenic effects. Source: Internet
Taken together, these data are highly supportive of the concept that levonorgestrel emergency contraception has little or no effect on postovulation events but is highly effective when taken before ovulation. Source: Internet