How effective is the morning-after pill?
The Julie Morning After Pill (and other OTC levonorgestrel pills) can reduce pregnancy risk by up to 89% if taken within 72 hours after unprotected sex, and is most effective within 24 hours. It works by preventing or delaying ovulation. Effectiveness drops for people with a BMI over 25, so Ella® (prescription) or a copper IUD may be better options for higher BMIs.
The over-the-counter morning-after pill is a form of emergency contraception that can reduce the risk of pregnancy by up to 89% if taken within 72 hours after unprotected sex. How does that translate to pregnancy risk? For any act of unprotected sex, baseline risk of pregnancy is around 10%. The morning-after pill takes that risk down to around 3%. It’s proven to be most effective if taken within 24 hours, so it’s always best to take it ASAP.
Levonorgestrel is the active ingredient in morning-after pills like Julie’s and was approved by the FDA way back in 1999, so you can sleep soundly knowing it’s solid. It’s also been used by millions of women for decades as an effective emergency contraception option for stopping a pregnancy before it starts. You’ll simply be joining a long line of women taking control of their reproductive freedom, which objectively rocks.
If you just had sex and you’re unsure whether you were fully protected, do yourself a favor and take the morning-after pill like Julie’s as soon as possible. You can easily find the Julie Morning After Pill™ at Target, CVS, Walmart and Amazon or get it delivered now through GoPuff, UberEats, Instacart and Doordash. Find a store near you.
Weight does impact the effectiveness of the morning-after pill
If you have a BMI above 25, the OTC morning-after pill may be less effective. In 2009, a study found that women taking emergency contraception with a BMI over 30 had a 3x greater risk of pregnancy than women with a BMI under 25 (5.8% compared to 1.7% risk). Unfortunately, the research doesn’t explain why that’s the case. Don’t fret: You still have options. Ella® is another type of emergency contraceptive pill that is more effective at higher BMIs. Like Julie’s, it’s a one-time pill – only you need a prescription from your medical provider to get it. The best overall form of emergency contraception is the IUD which is not affected by weight at all. However, there is a literal barrier to entry: An IUD needs to be inserted by a healthcare professional within five days after having unprotected sex.
What do you need to know about levonorgestrel?
Levonorgestrel is a progestin (a synthetic form of your body’s natural hormone progesterone), found in most oral and IUD contraceptives. Morning-after pills like Julie’s contain a much higher dose of progestin than daily birth control. Which takes us to our next point: The Julie Morning After Pill™ should not be used as a regular birth control method because it's not as effective as regular birth control. It acts like your body’s natural progesterone, attaching to progesterone and androgen receptors and suppressing the luteinizing hormone (LH) surge that causes ovulation. By stopping the LH surge, levonorgestrel stops ovulation and prevents your ovaries from releasing an egg.
Depending on where you are in your cycle, the morning-after pill helps to prevent or delay ovulation. It’s important to remember that levonorgestrel is not the abortion pill. It will not induce an abortion or miscarriage, nor will it harm a fetus. Levonorgestrel helps to prevent pregnancy —it does nothing to reverse it.
How effective is the morning-after pill when ovulating?
The Julie Morning After Pill™ is most effective when taken before ovulation (which happens about midway through your cycle) because it stops the ovaries from releasing an egg, making it unavailable for a sperm to fertilize after unprotected sex. No egg means no pregnancy. Voila! However, if the ovulation process has already started, the Julie Morning After Pill™ will not have any impact and pregnancy is possible. If you haven’t gotten your period within three weeks after taking the morning after pill, we recommend that you take a pregnancy test.
How do you know if you’re ovulating?
Tracking your cycle is an easy, helpful way to know what stage of your menstrual cycle you’re in. With good tracking you can determine when you’re ovulating and on which days you’re most fertile. Ovulation usually begins midway through your cycle, about 14 days before your period starts.
Some ways to tell that you’re ovulating include:
- Slight increases in your basal body temperature
- Cervical mucus or discharge becoming clearer, thinner, and more slippery
- Sex drive increases
- Light spotting
- Mild cramps in lower abdomen
There are a number of tools to help you track your cycle, from period tracking apps to taking your basal body temperature every morning. Tracking your period with a calendar is also fairly accurate for individuals with regular cycles.
How long are you protected against pregnancy?
Morning-after pills deliver a surge of the hormone levonorgestrel that causes a temporary interruption of your normal hormone signalling. Once you’ve taken the pill, the hormones will remain in your body for around five days, protecting you from sperm cells that can survive inside your uterus for roughly the same amount of time. But that doesn’t mean it will save you from future unprotected sex! If you’re planning to be sexually active, consider a regular form of birth control.
Does the Julie Morning After Pill™ affect your fertility?
No, neither Julie’s nor other morning-after pills will impact future fertility. Furthermore, the Julie Morning After Pill™ is not meant to be an ongoing form of birth control — it only stops ovulation in the short term. When you start a new cycle next month, you’ll go through a brand new ovulation phase, which is a new opportunity to get pregnant. If you’re planning on having babies in the future, rest assured your chances of getting pregnant won’t be affected by the Julie Morning After Pill, even if you take it multiple times.
Need the Julie Morning After Pill™ now? Pick up at Target, CVS, Walmart and Amazon or get it delivered now through GoPuff, UberEats, Instacart and Doordash. Find a store near you.
When used as directed, the Julie Morning After Pill™ is safe and effective. Common side effects may include changes in your period, nausea, lower abdominal pain, tiredness, headache, dizziness and breast tenderness. The Julie Morning After Pill™ will not protect you from HIV and other sexually transmitted diseases.
While we love to share useful and helpful information, the above shouldn’t replace the advice of your healthcare professional. For questions about birth control and other women’s health issues, please talk to your doctor.
Julie wants to keep young women in the driver’s seat of their own stories and provide them with the tools necessary for a happy, healthy sex life.
We know (and have lived!) through the ups and downs of young adulthood firsthand, and we aim to normalize the events, conversations, and questions that come during this period to help destigmatize sexual health. We believe women should live life with total freedom — starting with their ability to choose how, when, and if they become pregnant.
We know that women can make the best choices for themselves when equipped with the right information. We don’t take sexual education lightly and are committed to sharing accurate and factual information through rigorous planning and QA processes. In fact, all Julie content is reviewed by at least two board-certified doctors on our medical board. Learn more about them here.
For more details on our editorial process, see here.
Tessa Commers, MD, FAAP, MS is a board-certified pediatrician based in the Seattle area with a particular interest in adolescent health and sexual education. In addition to clinical practice and serving as Head of Medical at Julie, Tessa also founded AskDoctorT — an education platform with over a million followers across Instagram, TikTok, and YouTube — aimed at improving adolescent health literacy and body confidence. She also hosted and wrote the puberty podcast “That’s Totally Normal!” and has contributed to peer-reviewed publications and educational initiatives focused on child and adolescent wellbeing.
Education: Children’s Mercy Hospital, Kansas City – Pediatric Residency; University of Nebraska Medical Center – Doctor of Medicine (MD); University of Nebraska Medical Center – Master of Science (MS, Genetics, Cell Biology and Anatomy); New York University – Bachelor of Arts (BA)
Dr. Jennifer M. Peña, MD, FACP, AAHIVS is a board-certified internal medicine physician and physician leader with more than 20 years of experience in primary care and women’s health. An Army combat veteran, Jennifer served in the White House Medical Unit under two presidential administrations, including as primary physician to the Vice President of the United States.
She also serves as chief medical officer, medical director, practice owner, and advisor to healthcare and health tech organizations across the U.S., the Caribbean, and beyond. Jennifer’s work in medicine includes appearances on CNN, BBC, MSNBC, Univisión, and more, as well as being named one of Business Insider’s “30 Leaders Under 40 Changing Healthcare” and Veteran of the Year by Latina Style magazine.
Education: Walter Reed Army Medical Center – Internal Medicine Residency; William Beaumont Army Medical Center – Internal Medicine Internship; University of Pittsburgh School of Medicine – Doctor of Medicine (MD); Yale University – Bachelor of Science (BS)
