Emergency Contraception Side Effects

Emergency contraception (EC) is a “just-in-case” option used after unprotected sex or birth control failure to help
prevent pregnancy. The most common types in the U.S. are:
levonorgestrel pills (often called Plan B or “generic Plan B”),
ulipristal acetate (ella), and the copper IUD (ParaGard) used as emergency contraception.
Like most medicines and procedures, EC can come with side effectsusually short-lived, usually mild, and usually
more annoying than alarming.

This guide breaks down what side effects you might notice, how long they typically last, what’s considered normal,
and when it’s smart to get medical help. (Spoiler: your body is not “broken” because your period shows up acting
like it didn’t get the memo.)

First: What Emergency Contraception Is (and Isn’t)

Emergency contraception helps prevent pregnancy before it startsmainly by delaying or preventing ovulation.
It does not treat sexually transmitted infections (STIs), and it does not end an existing pregnancy.
If you’re already pregnant, EC won’t work to “undo” it.

Why Side Effects Happen

Side effects aren’t punishment, karma, or your hormones staging a coup. They’re usually the result of:

• Temporary hormone shifts (especially with levonorgestrel pills)
• Progesterone-receptor effects (with ulipristal/ella)
• Local uterine reaction and insertion effects (with a copper IUD)
• Stress (which can also affect sleep, nausea, and your cycle timing)

Common Side Effects (Across Most EC Options)

Most people who take an emergency contraception pill report either no side effects or mild ones that fade within a few days.
The most commonly reported effects include:

• Nausea (sometimes with vomiting)
• Headache
• Fatigue (that “I could nap for a living” feeling)
• Dizziness
• Breast tenderness
• Lower abdominal cramping
• Spotting or light bleeding
• Period timing changes (earlier, later, heavier, lighter, or just… weird)

One key thing to remember: the cycle right after EC can be a little unpredictable. That’s common and usually temporary.

Levonorgestrel EC (Plan B and Generics): Side Effects to Expect

Typical side effects

Levonorgestrel emergency contraception has a long track record in the U.S., and its side effects are usually mild.
The most commonly reported include menstrual changes, nausea, abdominal pain, fatigue, headache, dizziness, and breast tenderness.

Period changes (the #1 side effect people notice)

After levonorgestrel EC, your next period may:

• Arrive a few days earlier than expected
• Arrive a few days later than expected
• Be heavier or lighter than usual
• Come with spotting before it starts

This happens because levonorgestrel can shift ovulation timing, and your period timing follows ovulation like a
loyal (but slightly confused) puppy.

Nausea and vomiting

Feeling queasy is common. If you vomit soon after taking levonorgestrel EC, the dose may not be fully absorbed.
Some product labeling advises calling a healthcare professional if vomiting happens within about 2 hours.
If you’re unsure, a pharmacist or clinician can help you figure out what to do next.

Ulipristal Acetate (ella): Side Effects to Expect

Typical side effects

ella (ulipristal acetate) has a similar side-effect “vibe” to levonorgestrel, with a few differences because it works
through progesterone receptors. Commonly reported side effects include:
headache, nausea, abdominal pain, menstrual pain, fatigue, and dizziness.

Period delay and spotting

With ella, it’s not unusual for the next period to be a bit delayed. In clinical studies, some people had menses more than
a week earlier or later than expected, and some reported intermenstrual bleeding (spotting).

One important timing note (not about side effects, but about your next steps)

Because ulipristal interacts with progesterone receptors, it can affect how well some hormonal contraception works right away.
Clinical guidance often recommends using a reliable barrier method (like condoms) for a short window after ella and
being thoughtful about when to restart hormonal birth control. If you need a personalized plan, a pharmacist or clinician can help.

Copper IUD as Emergency Contraception: Side Effects to Expect

Insertion-related side effects (short-term)

Using a copper IUD as emergency contraception is extremely effective, but it’s also a procedure. Common short-term effects include:

• Cramping during or right after insertion
• Spotting or light bleeding for a few days
• Dizziness briefly after insertion (some people feel faintthis is usually temporary)

Bleeding and cramps in the first months (especially with copper)

Copper IUDs can cause heavier bleeding and more cramping, especially in the first few months.
Many people notice this settles over time, but it’s a real tradeoff for a highly effective, hormone-free option.

Rare but serious IUD concerns

Serious complications are uncommon, but it’s important to know the red flags. Rare risks include expulsion
(the IUD partially or fully coming out) and uterine perforation. If you can’t feel the strings, have worsening
pain/bleeding, or have severe symptoms, contact a clinician promptly.

How Long Do Emergency Contraception Side Effects Last?

Most pill-related side effects (nausea, headache, fatigue, dizziness) typically last a day or twosometimes up to a few days.
Bleeding changes can show up as:

• Spotting in the days after EC
• A next period that’s a few days early or late
• A cycle that feels “off” for that month

With a copper IUD, cramping and spotting are common right after insertion, and heavier periods/cramps can persist for a few cycles.

What’s Normal vs. What’s Not?

Usually normal (but annoying)

• Light spotting
• Mild-to-moderate cramps
• Nausea that improves within a day or two
• Headache or fatigue
• A period that’s a few days early or late
• A heavier or lighter next period

Call a healthcare professional soon if you notice:

• Your period is more than 7 days late (or significantly off from your usual pattern)
• Very heavy bleeding (soaking pads rapidly, large clots, or bleeding that feels “not like you”)
• Severe or worsening abdominal pain
• Fainting, severe dizziness, or symptoms that feel urgent
• Persistent vomiting that prevents you from keeping fluids down

Why severe abdominal pain matters (ectopic pregnancy warning)

A rare but serious issue after any contraceptive failure is ectopic pregnancy (a pregnancy developing outside the uterus).
Guidance and labeling note that severe lower abdominal painespecially in the weeks after ECshould be evaluated promptly.
It’s uncommon, but it’s one of those “don’t Google for three hoursjust get checked” situations.

Do Side Effects Mean Emergency Contraception Worked?

Not really. Side effects can happen whether or not EC prevents pregnancy. The best “sign” is your next period arriving
around the expected time (give or take a few days). If your period is significantly delayed, taking a pregnancy test can provide clarity.

Can Emergency Contraception Affect Future Fertility?

Emergency contraception does not “use up your eggs,” does not cause infertility, and does not permanently disrupt your cycle.
It’s designed for occasional use. That said, if you find yourself needing EC frequently, it might be worth exploring a regular method that fits your life
(because convenience is a valid health goal).

Drug Interactions and Situations That Can Change What You Feel

Medications and supplements

Some medicines and herbal products can reduce the effectiveness of certain EC options by affecting how they’re metabolized.
Examples often include certain seizure medications, rifampin, and St. John’s wort. If you’re on long-term medication, a pharmacist can be a fast,
judgment-free resource.

Body weight and effectiveness (side effects vs. effectiveness)

People often mix up two questions: “Will I feel worse?” and “Will it work as well?” Weight doesn’t reliably predict side effects, but it may affect effectiveness
for some oral EC options. If you’re worried about effectiveness, a clinician can help you choose the most effective option for your situation.

How to Manage Emergency Contraception Side Effects

• Nausea: Small meals, bland foods, ginger tea, and staying hydrated can help. If you tend to get nausea with meds, ask a pharmacist about anti-nausea options.
• Headache: Hydration, rest, and over-the-counter pain relief (used as directed) may help. If headaches are severe or unusual for you, get medical advice.
• Cramps: A heating pad and typical OTC pain relief can help. With a copper IUD, cramps may be stronger early onheat and rest are your friends.
• Spotting: Panty liners and patience. If bleeding becomes heavy or prolonged, check in with a clinician.
• Anxiety: Totally common. Consider setting a reminder for when to test if your period is latefuture-you will appreciate the plan.

Emergency Contraception Side Effects FAQ

Can emergency contraception make you bleed right away?

Yes. Some people have spotting or light bleeding after taking EC pills. This doesn’t automatically mean anything is wrong.

Can emergency contraception cause a late period?

Yes. Your next period may arrive earlier or later than usual. If it’s more than about a week late, consider a pregnancy test and/or contact a clinician.

Is it normal to feel emotional after taking emergency contraception?

Emotional swings aren’t the most “officially listed” side effect, but stress, sleep disruption, and hormone shifts can affect mood.
If you feel overwhelmed, reaching out to a trusted person or healthcare professional can help.

Does emergency contraception protect against STIs?

No. EC prevents pregnancy, not infections. If you might have been exposed to an STI, consider testingmany clinics offer confidential services.

What if I took EC and then had unprotected sex again?

EC pills work for sex that already happened; they’re not “armor” for the rest of the month. If you have unprotected sex again,
you may still be at risk of pregnancy. A clinician can help you decide what to do next and discuss ongoing contraception options.

Conclusion

Emergency contraception side effects are usually temporary: a little nausea, a headache, some fatigue, maybe spotting, and a next period that’s a few days off schedule.
The biggest job of EC isn’t to make you feel amazingit’s to help prevent pregnancy after a contraceptive mishap. If you have severe pain, very heavy bleeding,
or a period that’s significantly late, it’s worth checking in with a healthcare professional.

Your body may act a little dramatic for a short time (honestly, relatable). But for most people, emergency contraception is safe, effective, and followed by a quick return to normal.

Real-World Experiences with Emergency Contraception Side Effects (What People Commonly Report)

Let’s talk about the part no one puts on the front of the box: the lived experience. Not “medical drama” lived experiencemore like “my body is being mildly inconvenient”
lived experience. While everyone’s different, there are some patterns people commonly describe after taking emergency contraception.

1) The nausea is usually the first guest to arrive. Many people say they feel queasy within a few hours, especially if they took the pill on an empty stomach
or when they were already anxious. Some describe it as the same kind of nausea you might get from skipping lunch and then remembering you’re human. A lot of folks say it
passes quickly with water, crackers, or a light meal. Others report it’s more “waves” than constantannoying, but manageable.

2) The fatigue can feel strangely specific. People often mention feeling tired in a way that’s not quite “I stayed up late” and not quite “I’m sick,” but
more like “my body wants to power down and restart.” That can be partly the medication and partly the stress come-down after a scary moment. Many say a nap helps. Others
say they just feel low-energy for a day and then bounce back.

3) Spotting is the side effect that sends people to the internet at 2 a.m. Light bleeding or spotting can happen, and it’s one of the most common reasons
people start spiraling: “Is this implantation bleeding? Is this a sign? Is my uterus sending Morse code?” In real life, many report spotting that lasts a day or two, or
spotting that pops up briefly and disappears. The key theme: spotting alone doesn’t confirm anything. It’s often just the hormonal shift.

4) The next period might show up with a different personality. A lot of people describe their next period as early, late, heavier, lighter, or just “off.”
Some say cramps were stronger than usual; others say cramps were weirdly mild. Some report a shorter period, while others say it lingered. A common emotional response is
frustrationbecause uncertainty is exhausting. Many people feel relieved once bleeding starts, even if it’s not perfectly on schedule.

5) Headaches and breast tenderness get honorable mentions. People often describe mild headaches that feel like dehydration or tension headaches, and breast
tenderness that feels similar to premenstrual symptoms. These symptoms can be extra confusing because they overlap with early pregnancy symptoms. That overlap is why
guidance often focuses on timing: if your period is significantly late, testdon’t try to interpret every sensation like it’s a clue in a mystery novel.

6) With a copper IUD, the experience is different because it’s a procedure. People who use a copper IUD as emergency contraception often describe insertion
day as the “main event.” Some report intense cramping during and right after, followed by a day or two of crampy soreness and spotting. Others say it was uncomfortable
but quick. In the following months, a common theme is heavier bleeding and stronger cramps at first, then improvement over time. People also frequently mention peace of
mind afterward because the copper IUD continues to provide ongoing contraception.

7) The emotional side is real, too. Many people describe anxiety, irritability, or feeling “on edge” after taking ECnot necessarily because the medication
directly causes it, but because the situation is stressful. Waiting for a period can feel like waiting for exam results: your brain keeps refreshing the page. What helps,
according to many people, is making a plan (when to test, who to call if you’re worried) and then trying to return to normal routines as much as possible.

If there’s one takeaway from real-world experiences, it’s this: most side effects are temporary and manageable, and the emotional whiplash is often part of
the story. If symptoms feel severe, don’t improve, or scare youtrust that instinct and get medical advice. You’re not being dramatic. You’re being responsible.