There is no limit to the amount of Plan B you can take in a month and no suspected health risks (including risk to fertility) associated with frequent use. However, there has been evidence that continual use can reduce its effectiveness. However, it is important to not minimize the effect such a high-dose hormone pill can have on the body. Reported side effects include dizziness, upset stomach, headaches, nausea and emotional upheaval. Taking Plan B more than once in a short time can intensify and prolong these side effects. Many users report disruptions in their menstrual cycle, weight gain and lethargy. It is important to state that Plan B should not be considered an effective form of birth control. While there are no direct, permanent side effects associated, this does not mean it’s not worth the suffering! If you notice you have a habit of taking Plan B frequently, it is recommended to look into other, less potent birth control. Plan B works by delaying or stopping the release of the egg from the ovary and has an effectiveness of 89% if taken within 72 hours of unprotected sex. It is important to note that it does not protect against STIs. The hormone levonorgestrel is used to prevent ovulation when semen is in the uterus. Subsequently, it is only effective if the egg has either already or not yet been released from the fallopian tube. Other birth control such as pills, IUDs and NuvaRings allow for a consistent, low dosing of hormones that completely stop ovulation for protecting against pregnancy with effectiveness up to 99%. So while you can take as much Plan B as you want, it is important to listen to your body and explore other, more effective birth control treatments.