How late can the second dose of emergency contraceptive pills be taken to remain effective?
Jun 01, 2023
Source: Cainiu Health
Dr. Lv Aiming
Introduction
The second dose of emergency contraceptive pills must be taken within 12 hours at the latest to remain effective. Emergency contraceptives are generally divided into two types, one being levonorgestrel. This drug is a fully synthetic, potent progestin. Its primary mechanism of action is to inhibit ovulation by suppressing the hypothalamus and pituitary gland, thinning the endometrial lining, and thereby preventing sperm implantation.
The second dose of emergency contraceptive pills must be taken within 12 hours to remain effective. Specific details are as follows:
Emergency contraceptives generally come in two types. The first is levonorgestrel, a fully synthetic, potent progestin. Its primary mechanism involves suppressing ovulation by acting on the hypothalamus and pituitary gland, thinning the uterine lining to prevent implantation of sperm, and thickening cervical mucus to block sperm penetration. This medication typically comes in two doses: one tablet is taken first, followed by a second tablet 12 hours later. Therefore, the second tablet must be taken no later than 12 hours after the first. The other type is a single-dose pill, which should be taken as soon as possible after unprotected intercourse. The second major type is mifepristone, an antiprogestin that prevents implantation of the fertilized egg and promotes cervical ripening. For the two-tablet regimen of mifepristone, the dosing schedule is the same as described above; however, for the single-dose version, it can be taken within 120 hours after intercourse.
Patients are advised to visit a正规 medical institution and take these medications under the guidance of a physician. Do not take them blindly, to avoid potential adverse effects.
