Plan B, also known as the "morning-after pill," is a type of emergency contraception that contains levonorgestrel, a synthetic hormone. After taking Plan B, levonorgestrel is rapidly absorbed into the bloodstream and metabolized by the body.
The half-life of levonorgestrel, the active ingredient in Plan B, is relatively short, estimated to be around 24 to 36 hours. This means that it takes approximately 24 to 36 hours for the concentration of levonorgestrel in the bloodstream to decrease by half.
However, it's important to note that traces of levonorgestrel may still be detectable in the body for a longer period of time, particularly in urine or blood tests. While levonorgestrel is generally eliminated from the body within a few days, individual factors such as metabolism and kidney function can affect the clearance rate.
In terms of its contraceptive effects, Plan B is designed to prevent pregnancy by delaying ovulation or interfering with fertilization. It is not intended to have a long-lasting impact on the body's hormonal balance or fertility. After taking Plan B, menstrual bleeding may occur within a few days to a week, but this is not considered a period and does not necessarily indicate that the medication is still active in the body.
If you have any concerns about the duration of Plan B's effects or its impact on your health, it's important to consult with a healthcare provider for personalized guidance and advice.