What Is the Emergency Contraceptive Pill?
The emergency contraceptive pill is a form of contraception taken orally if someone has had unprotected sexual intercourse and is not covered by another contraceptive method on that occasion. Emergency contraceptive pills (ECPs) are also known as Plan B, the morning-after pill, or post-coital contraceptives. Depending on the type of ECPs available in your country, the medication must be taken within either 120 hours (five days) or 72 hours (three days) to be effective. However, the sooner you take the pills, the more effective they will be at preventing pregnancy.
Although a well-known method of emergency contraception, ECPs are shrouded in misinformation and myths. Dispelling the ignorance surrounding ECPs is the first step towards building a well-informed sexually educated population and reducing the rate of unwanted pregnancies, not to mention stopping the stigma around people who use ECPs.
How Does the Emergency Contraceptive Pill Work?
There are three different emergency contraceptive pills, and their exact mechanism of action differs. However, essentially, emergency contraceptive pills work by preventing or delaying ovulation (the release of the ovule from the ovaries), preventing fertilization before it has even started. As you can see, this function does not affect an already fertilized egg; therefore, it is impossible for ECPs to induce abortion.
The type of ECP called ulipristal acetate (UPA) prevents ovulation because as a selective progesterone (a hormone essential to the ovulation process) receptor modulator, it can bind to the progesterone receptors, which will prevent or delay discharge of the egg, decreasing the thickness of the endometrium as well (6).
Several studies clearly show that levonorgestrel (a synthetic progestogen) can stop or delay ovulation. When taken before ovulation, it prevents the luteinizing hormone (LH) from triggering the release of an egg, thereby preventing the egg from maturing or being released (7).
Levonorgestrel’s effect on sperm is inconclusive, although it has been suggested that the drug has little impact on cervical mucus or sperm function and is not effective at stopping ovulation during the most fertile days of the menstrual cycle or if ovulation has already happened (5).
Types of Emergency Contraceptive Pills and When to Use Them
Emergency contraception may be needed in several situations, including when:
- contraception hasn’t been used during sex;
- a woman has been sexually assaulted; and
- there are concerns about contraceptive failure, such as:
- a condom breaking, slipping, or being used incorrectly;
- missing three or more birth control pills, especially during the first week of the cycle.
- taking the mini-pill more than three hours late or the desogestrel pill more than 12 hours late;
- delaying contraceptive injections beyond their scheduled time;
- issues with diaphragms or cervical caps, like dislodgement or tearing;
- withdrawal failure, where ejaculation occurs in or near the vagina;
- problems with spermicides not working properly;
- misjudging the safe period when using fertility awareness methods; and
- the expulsion of an IUD or hormonal implant.
In short, if contraception wasn’t used, failed, or was misused, emergency contraception can help prevent pregnancy (3).
The dosage and timing differ according to each type of ECP.
There are three main types of ECPs. We’ve already discussed levonorgestrel and ulipristal acetate; however, there is a third method that can be included as an ECP – the Yuzpe regimen, which involves combined oral contraceptives (COCs) (1).
Levonorgestrel is a synthetic progesterone that prevents/delays fertilization. Examples of these pills include Lydia Postpil, Postinor 2, Norpill, Unwanted72, Nowill Pill, Plan B One-Step, Next Choice One Dose, Next Choice, My Way, After Pill, and levonorgestrel. ECPs with levonorgestrel can be taken as a single 1.5 mg dose or two 0.75 mg doses spaced 12 hours apart.
Ulipristal acetate’s mechanism of action is a little bit different from levonorgestrel. Ulipristal can also affect the implantation process by decreasing the thickness of the endometrium. The most popular example of this drug is Ella, and it is taken as a single dose of 30 mg.
The lesser-known Yuzpe regimen involves a dose of 100 μg of ethinyl estradiol taken with 0.50 mg of LNG, and then, a second dose with the same amounts is repeated 12 hours later.
Effectiveness of Emergency Contraceptive Pills
Emergency contraception (EC) can prevent more than 95% of pregnancies if used within five days after sexual intercourse. Effectiveness varies according to the type of pill and when the ECPs are taken.
Regarding levonorgestrel, the information varies. However, it is generally agreed that the effectiveness of LNG decreases the longer you delay taking it after intercourse. According to the World Health Organization (WHO), ECPs with UPA have a pregnancy rate of 1.2% and LNG has a pregnancy rate of 1.2% to 2.1%. Based on a study, levonorgestrel-only emergency contraceptive has an efficiency rate of 89% if it is used correctly, within 72 hours after unprotected intercourse (4).
ECPs are less effective if taken during ovulation because they primarily work by preventing or delaying ovulation. If ovulation has already occurred, ECPs are less likely to prevent pregnancy since they can’t stop the egg from being fertilized or implanted. That is why it is highly recommended that ECPs (ulipristal acetate, levonorgestrel, COCs) are taken within 120 hours after intercourse. Out of all the ECPs, Ella (ulipristal) is the most effective when taken 72 to 120 hours after unprotected sex.
Side Effects and Considerations
While it is true that there are some side effects associated with ECPs, they are usually mild and short-term. Side effects may include:
- headaches,
- abdominal pain,
- fatigue,
- dizziness,
- nausea,
- breast tenderness, and
- irregular bleeding.
Your next period might come early or late and you could experience some spotting between periods.
Any woman or girl of reproductive age may require emergency contraception to prevent an unwanted pregnancy. There are no absolute medical reasons that would contraindicate someone from using emergency contraception, and there are no age restrictions on its use.
However, ulipristal acetate might not be the best option if you have severe asthma and are taking glucocorticoids as it may have anti-glucocorticoid effects. Additionally, research from the Centers for Disease Control and Prevention suggests that emergency contraceptive pills may be less effective at preventing pregnancy for women who are obese (with a body mass index of 30 or higher) (8).
Where to Obtain Emergency Contraceptive Pills
Levonorgestrel, ulipristal acetate, and COCs are widely available in most countries and can be found at pharmacies and clinics. Depending on the country, they are available with or without a prescription.
You can find out where to obtain ECPs in your country by visiting Find My Method.
Myths and Facts About Emergency Contraceptive Pills
- Myth: There’s only one type of Plan B.
Fact: As discussed, there are three types: levonorgestrel, ulipristal acetate, and COCs. - Myth: You only need to take ECPs once, and pregnancy can be prevented even if you have unprotected intercourse afterward.
Fact: You need to take ECPs every single time you have unprotected intercourse. - Myth: ECPs cause abortion.
Fact: This is false. Abortion pills and ECPs work completely differently from one another. ECPs only prevent the process of fertilization. - Myth: ECPs are very harmful to your health, so you’re not allowed to take them frequently.
Fact: It is true that using a long-term contraceptive method is better than resorting to ECPs every time you have intercourse because long-term contraception is more effective, provides consistent hormone levels, and is safer for regular use compared to emergency contraceptive pills (ECPs), especially if used frequently. It also offers greater convenience and is more cost-effective over time.
However, ECPs are completely safe, regardless of how many times they’re used. - Myth: ECPs affect fertility.
Fact: No, ECPs have no effect, either short-term or long-term, on fertility, and there’s no delay in the return to fertility after using them either. - Myth: You can’t use ECPs if you’re underage.
Fact: False, ECPs can be used by people of all ages.
In Conclusion
All in all, we have learned about what emergency contraceptive pills are, how they work, and, most importantly, that they are safe, effective, and can be used by people of all ages. However, if you still find yourself pregnant after taking an ECP, you can discuss your options on how to navigate your unplanned pregnancy with our counselors at safe2choose.
Frequently Asked Questions About Emergency Contraception Pills
- If I have intercourse after taking an ECP, do I need to take them again?
Answer: Yes, you can still get pregnant after taking the morning-after pill. It helps prevent pregnancy from the sex you had before taking it, but not for any sex afterward. If you have unprotected sex again, you’ll need to take another dose. For example, if you have intercourse five times, you have to take them five times. That’s why it’s best that you use a condom if you plan to have intercourse multiple times in one day. - Will it affect my pregnancy if I accidentally take ECPs during an unknown pregnancy?
Answer: If you accidentally take an ECP while unknowingly pregnant, it is unlikely to harm the pregnancy. ECPs are designed to prevent pregnancy before it occurs, and there is no evidence that they negatively affect an existing pregnancy. - How many times can I use ECPs?
Answer: As many as you’d like! They are completely safe. However, if you’re sexually active, it is recommended that you partake in long-term contraceptive methods instead, since it’ll decrease your chances of an unwanted pregnancy in case you forget to take the morning-after pill. - If I’m on birth control, how should I get back to taking birth control pills after taking ECPs?
Answer: If you usually use birth control pills, a patch, or a vaginal ring but have missed some doses, start using them again the day after taking emergency contraception. However, you’ll need to use a backup method, like condoms, for at least seven days. Likewise, remember that contraception is a two-way responsibility. - Why is my period delayed after taking an ECPs vs. regular contraception?
Answer: After taking ECPs, your period might be delayed due to the high dose of hormones that can temporarily disrupt your menstrual cycle. Menstrual cycle events are ruled by hormones, so any new hormonal interaction can change the previous stable pattern. ECPs work differently from regular contraception, which is taken consistently to maintain a stable hormone level. The sudden hormone change from ECPs can cause your period to arrive later or earlier than expected. - How do ECPs differ from abortion pills?
Answer: ECPs prevent pregnancy by delaying or stopping ovulation and are taken shortly after unprotected sex. They do not affect an existing pregnancy. In contrast, abortion pills are used to terminate an already established pregnancy by inducing a miscarriage. ECPs are for prevention, while abortion pills are for ending a pregnancy. The two serve entirely different purposes and work at various stages.
- “Emergency Contraceptive Pills Contraindications.” Find My Method, findmymethod.org/birth-control-options/emergency-contraception/contraindications#content. Accessed August 2024.
- “What is the difference between morning-after pill and abortion pill?” safe2choose, safe2choose.org/faq/abortion-facts/difference-between-morning-after-pill-and-abortion. Accessed August 2024.
- “Emergency Contraception.” WHO, 2021, www.who.int/news-room/fact-sheets/detail/emergency-contraception. Accessed August 2024.
- Shohel, M, et al. “A systematic review of effectiveness and safety of different regimens of levonorgestrel oral tablets for emergency contraception.” NIH, 2014, www.ncbi.nlm.nih.gov/pmc/articles/PMC3977662/. Accessed August 2024.
- Peck, R., et al. “Does levonorgestrel emergency contraceptive have a post-fertilization effect? A review of its mechanism of action.” NIH, 2016, www.ncbi.nlm.nih.gov/pmc/articles/PMC5102184/#:~:text=The%20drug%20has%20minimal%20effects,fertile%20days%20of%20the%20cycle. Accessed August 2024.
- Kim, A. & Bridgeman, MB. “Ulipristal acetate.” NIH, 2011, www.ncbi.nlm.nih.gov/pmc/articles/PMC3138379/#:~:text=Ulipristal%20acetate%20exerts%20its%20pharmacological,(by%20decreasing%20endometrial%20thickness). Accessed August 2024.
- “Mechanism of Action for Emergency Contraception.” FIGO, 2009, www.figo.org/mechanism-action-emergency-contraception. Accessed August 2024.
- “Emergency Contraception.” Office on Women’s Health, 2023, www.womenshealth.gov/a-z-topics/emergency-contraception#references. Accessed August 2024.
- “Contraceptive Use Around the World.” Find My Method, findmymethod.org/contraceptive-use-around-the-world. Accessed August 2024.