Plan B, also known as the morning-after pill, is a form of emergency contraception designed to prevent pregnancy following unprotected sexual intercourse or contraceptive failure. This medication contains a high dose of levonorgestrel, a synthetic hormone. Its purpose is to act as a backup method, not a routine form of birth control.
How Plan B Works
Plan B primarily works by temporarily delaying or preventing ovulation, the release of an egg from the ovary. By delaying ovulation, the medication aims to prevent the egg from being available for fertilization.
Plan B is most effective when taken as soon as possible after unprotected sex, ideally within 72 hours (three days), though some formulations can be effective for up to 120 hours (five days). It does not work if ovulation has already occurred. Furthermore, it does not terminate an existing pregnancy and will not affect an implanted fertilized egg. The effectiveness of the medication decreases significantly with time, emphasizing the need for prompt use.
Immediate Effects of Taking More Than One Dose
Taking two doses of Plan B, either simultaneously or close together, means ingesting a higher amount of levonorgestrel than the recommended single dose. While this increased hormonal load can lead to more pronounced side effects, it is generally not considered medically dangerous or life-threatening. Common side effects include nausea, vomiting, dizziness, fatigue, headaches, and breast tenderness. Changes in menstrual bleeding patterns can involve an earlier or later period, heavier or lighter bleeding than usual, or even spotting between periods. Most of these temporary side effects typically resolve within 24 to 48 hours.
Impact on Contraceptive Effectiveness
Taking more than the recommended single dose of levonorgestrel emergency contraception does not increase its effectiveness in preventing pregnancy. The medication’s primary action is to delay ovulation, and providing an additional dose does not enhance this effect. Plan B’s effectiveness is primarily time-dependent, meaning it works best the sooner it is taken after unprotected sex, rather than being dose-dependent. Doubling the dose does not double the protection. While there is no known long-term harm from taking multiple doses, frequent use is not recommended as a primary birth control method because it is less effective than other forms of contraception.
When to Seek Medical Advice
It is advisable to contact a healthcare professional in specific situations after taking Plan B.
If severe abdominal pain occurs, as this could indicate a serious condition such as an ectopic pregnancy (a pregnancy outside the uterus).
If bleeding is unusually heavy or prolonged beyond what is typical for a menstrual period.
If a menstrual period is missed by more than a week after taking Plan B, as this might suggest a pregnancy.
If vomiting occurs within two hours of taking the pill, as the medication may not have been fully absorbed and another dose might be necessary under their supervision.