This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: NEET Jan 2020, Subject name: Pharmacology
Which of the following is not used as emergency contraceptive? 
Select and explain. 
A. Danazol, B. Levonorgestrel, C. Mifepristone, D. IUCD
A: Danazol
Answer: A: Danazol 
Explanation: Isoxazole derivative of 17 - alpha ethinyl testosterone propeies Causes atrophy of endometrium It is strictly antigonadotropin but acts as an androgen agonist Mode of action Acting on the hypothalamo - pituitary - gonadal axis - depression of frequency of GnRh pulses - suppression of pituitary FSH and LH surge. There is however no change in the basal gonadotropin level Indication of danazol Endometriosis DUB Symptomatic fibroid Precocious pubey