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Emergency Contraception: Levonorgestrel vs. Ulipristal Acetate — What You Need to Know
A broken condom, a missed pill, or an unplanned moment — learn the differences between Plan B and Ella, and which one is right for you based on timing and BMI.
Emergency Contraception: Levonorgestrel vs. Ulipristal Acetate — What You Need to Know
A broken condom, a missed pill, or an unplanned moment — whatever brought you here, you're not alone, and you have options. Emergency contraception (EC) is a safe, time-sensitive way to prevent pregnancy after unprotected sex. The key is acting quickly — the sooner you take it, the more effective it is. This guide explains everything you need to know about the two most common emergency contraceptive pills: Plan B (levonorgestrel) and Ella (ulipristal acetate).
Key Takeaway
Emergency contraception prevents pregnancy — it does NOT terminate an existing one. Both Plan B and Ella work by delaying or preventing ovulation. The right choice depends on two factors: how much time has passed since unprotected intercourse, and your BMI.
Levonorgestrel 1.5 mg Emergency Contraception
Plan B is a single-dose emergency contraceptive pill containing levonorgestrel, a synthetic progestin. It works primarily by delaying or preventing the release of an egg from the ovary. When taken within 72 hours (3 days) of unprotected intercourse, it is approximately 89% effective at preventing pregnancy. Effectiveness decreases the longer you wait — so time is critical.
- Best for: Individuals with a BMI under 30 who need EC within 72 hours.
- Key advantage: You can immediately resume or start your regular hormonal birth control after taking it.
- Common side effects: Nausea, fatigue, headache, and changes to your next period.
Ulipristal Acetate 30 mg Emergency Contraception
Ella is a prescription-only emergency contraceptive that works as a selective progesterone receptor modulator. It can delay ovulation even when taken close to the time of ovulation, making it the more clinically advanced option. Ella remains highly effective for up to 120 hours (5 full days) after unprotected intercourse, and is the preferred choice for individuals with a BMI of 30 or higher, where levonorgestrel may be less effective.
- Best for: Individuals with BMI ≥ 30, or when more than 72 hours have passed since intercourse.
- Key consideration: You must wait 5 days before starting or resuming hormonal birth control. Use a barrier method (condoms) during this time.
- Common side effects: Headache, nausea, abdominal pain, and menstrual changes.
Plan B vs. Ella
Choosing the right treatment starts with understanding the difference.
| Feature | Levonorgestrel | Ulipristal Acetate |
|---|---|---|
| Effective Window | Up to 72 hours (3 days) | Up to 120 hours (5 days) |
| BMI Consideration | Most effective for BMI < 30 | Preferred for BMI ≥ 30 |
| Prescription Required? | Available OTC, but prescribed through Herexa | Prescription only |
| Resume Birth Control | Immediately | Wait 5 days |
| Mechanism | Delays ovulation | Delays ovulation (stronger effect near ovulation) |
How Our System Recommends the Right Pill
Learning about emergency contraception is the first step. If the situation described in this article applies to you, HERAtime offers physician-reviewed care designed to help you access emergency contraception quickly and privately.
Who Should NOT Use Emergency Contraception Pills
- You are already pregnant (EC will not work and is not an abortion pill)
- You are experiencing severe abdominal or pelvic pain (may indicate ectopic pregnancy — seek ER care)
- You have a known allergy to levonorgestrel or ulipristal acetate
- You are taking interacting medications such as rifampin, anti-seizure drugs, or St. John's Wort (these significantly reduce effectiveness)
Need Emergency Contraception Now?
Complete a quick, confidential health assessment and a board-certified OB-GYN will review your case today. Most prescriptions are sent to your pharmacy the same day.
How to Get Started
Getting emergency contraception through Herexa Health is fast, private, and designed for urgency.
Complete our secure clinical intake with questions about timing, BMI, and medical history.
A Florida and New York licensed OB-GYN reviews your profile and selects the safest, most effective medication for you.
Your electronic prescription is sent to your preferred local pharmacy for same-day pickup.
Time matters. Don't wait. At Herexa Health, we understand the urgency and the privacy you deserve. Our board-certified OB-GYNs are here to get you the right medication, safely and quickly, on your schedule.
Which is more effective?
Can I take EC if I'm on birth control?
Ready to Get Care Today?
Answer a few private questions to see if treatment is right for you. Fast, respectful care — reviewed by a licensed OB-GYN.
