It is essential that people who decide to use the Plan B pill continue to take their birth control pills as usual unless a doctor advises otherwise. Taking both types of pill can provide a more lasting form of contraception.
The Plan B pill usually contains higher doses of hormones than birth control pills so taking both pills can cause some side effects.
Is It safe to take Plan B while on birth control?
According to the manufacturers of Plan B One-Step, people should resume taking birth control pills immediately after taking the Plan B pill.
Taking birth control pills after taking the Plan B pill can help to prevent unwanted pregnancy going forward.
Does it affect the next period?
A person should continue to use birth control while taking the Plan B pill.
Taking the Plan B pill in addition to continuing to take birth control pills may result in the next period being slightly different than usual.
For example, periods may:
- be earlier or later than expected
- be heavier or lighter than usual
- cause more symptoms, such as nausea or cramping
If a person's period is more than a week later than expected after taking Plan B, they should take a pregnancy test to rule out pregnancy. Anyone who has concerns about taking birth control pills or the Plan B pill should talk to a doctor.
How does Plan B work?
It is possible to take the Plan B pill up to 3 days after unprotected sex, even though many people call it the "morning-after" pill. However, the sooner a person takes Plan B following unprotected intercourse, the more effective it is in preventing pregnancy.
The Plan B pill contains 1.5 milligrams (mg) of the hormone levonorgestrel. Levonorgestrel is a synthetic chemical that mimics the natural hormone progesterone. It triggers several responses in the body that prevent pregnancy.
Levonorgestrel ensures that the body is:
- Preventing ovulation, the process by which the ovary releases an egg. If there is no egg to fertilize, pregnancy is not possible.
- Thickening the mucus in the cervix, which helps prevent sperm from reaching the uterus and combining with an egg.
- Thinning the uterine lining, which reduces the likelihood of a fertilized egg attaching to the uterus.
There are many misconceptions regarding how the Plan B pill works. The pill is not an abortion pill as it does not destroy or damage a fetus. Instead, it prevents a pregnancy from occurring in the first place. Once an embryo has implanted in the uterus, Plan B will not disrupt it or cause an abortion.
Who can take Plan B?
A person who is already pregnant should not take Plan B.
Anyone who has had unprotected sex or failure of their birth control method can take the Plan B pill. This pill is available without a prescription and has no age restrictions.
Some people should avoid taking Plan B, including those who are:
- already pregnant
- allergic to levonorgestrel or any other ingredients present in the Plan B pill
- trying to use it as an alternative to regular birth control (Plan B is effective in one-time doses, but is not suitable for routine pregnancy prevention)
- male, as the hormone is not effective in preventing a male from getting females pregnant
What to expect after taking Plan B
There are some potential side effects of taking the Plan B pill. Side effects are usually most significant in the 1–2 days after taking the pill and should subside after that.
A primary consequence of taking the pill is that the next period may be different regarding timing, flow, and side effects.
If a person's period is more than a week late, they should take a pregnancy test to ensure that they are not pregnant.
It is essential to understand that taking the Plan B pill does not protect people from sexually transmitted infections (STIs).
What are the side effects of Plan B?
Taking Plan B can cause side effects in some people due to the elevated hormone levels in the body.
Typical side effects may include:
- breast tenderness
- a headache
- irregular bleeding
Some people may find that taking anti-nausea medications, such as Dramamine, or taking Plan B on a full stomach makes them less likely to experience stomach-related side effects.
How Plan B interacts with other medications
Some medications can make Plan B less effective.
The Plan B pill contains larger amounts of the hormones that are present in birth control pills.
Taking this emergency contraceptive causes a boost in the body's hormone levels, which increases the likelihood of preventing pregnancy.
However, there are medications and herbal supplements that could affect the way the Plan B pill works.
Medications that may make Plan B less effective include:
- St. John's wort
People should always ask a doctor or pharmacist about any medications they may be taking and how they could impact the effectiveness of Plan B medication.
People should continue taking birth control pills as usual even after taking the Plan B pill.
The Plan B pill is only intended to be an emergency medication, not a regular method of contraception.
If someone has difficulty maintaining a regular birth control pill schedule, they should talk to their doctor about other birth control methods, such as intrauterine devices (IUDs).