The Sound of Evolution
Norgestimate
諾孕酯
Mechanism of action:
Norgestimate 是一種合成黃體素（synthetic progestin），為 19-去甲睪酮（19-nortestosterone）衍生物。Norgestimate 透過負回饋作用抑制下視丘-腦下垂體-性腺軸（hypothalamic-pituitary-gonadal axis），降低黃體成長激素（LH）峰值的產生，使卵泡無法正常破裂，從而抑制或延遲排卵。Norgestimate 也會使子宮頸黏液變得濃稠，阻礙精子通過子宮頸進入子宮腔，降低受精可能性。此外，norgestimate 能使子宮內膜維持在較薄、非增生狀態，即使受精發生，也不利於胚胎著床。
Reference(s):
1. Saxena A et al. (2015). Quantification of 17-desacetyl norgestimate in human plasma by liquid chromatography-tandem mass spectrometry (LC-MS/MS) and its application to bioequivalence study. J Pharm Anal.
2. Ahire D et al. (2017). Metabolite Identification, Reaction Phenotyping, and Retrospective Drug-Drug Interaction Predictions of 17-Deacetylnorgestimate, the Active Component of the Oral Contraceptive Norgestimate. Drug Metab Dispos.
3. Hammond GL et al. (2003). Serum distribution of the major metabolites of norgestimate in relation to its pharmacological properties. Contraception.