I-Pill (Levonorgestrel) vs. Other Emergency Contraceptives - Quick Comparison

Quick Takeaways

• Levonorgestrel (I‑Pill) works best within 72hours, but its effectiveness drops after 48hours.
• Ulipristal acetate (Ella) remains licensed up to 120hours with a more stable failure rate.
• The copper IUD can be inserted up to 5days after unprotected sex and is the most effective EC option.
• Combined estrogen‑progestin (Yuzpe) regimens are less convenient and have more nausea.
• Prescription requirements, cost and side‑effect profiles differ, so personal circumstances dictate the best choice.

When you need a backup option after unprotected sex, the market offers several emergency contraceptive (EC) choices. Understanding how I-Pill is a levonorgestrel‑based pill approved in the UK for up to 72hours post‑coitus compares to alternatives can save you time, cost and anxiety.

Ella (Ulipristal acetate) is a prescription‑only pill that works up to five days and maintains a steadier failure rate across the whole window.

The Yuzpe regimen uses two doses of a combined estrogen‑progestin pill taken 12hours apart, a method that predates modern single‑dose options.

For the highest efficacy, the copper IUD (Paragard) can be inserted up to five days after intercourse, turning a short‑term rescue into a long‑term contraceptive.

In some countries, mifepristone combined with misoprostol is approved as a later‑stage EC, but it requires medical supervision and is less common in the UK.

In the US, PlanB One‑Step is essentially the same levonorgestrel formulation as the I‑Pill, sold under a different brand.

Overall, emergency contraception refers to any method used after intercourse to prevent pregnancy, distinct from routine birth control.

Most EC pills belong to the broader class of hormonal contraception, which modulates ovulation, fertilisation or implantation.

How the I‑Pill Works

Levonorgestrel is a synthetic progestogen. Taken as a single 1.5mg dose, it either stops ovulation or thickens cervical mucus, making it harder for sperm to reach an egg. The pill must be taken as soon as possible; the sooner you swallow it, the higher the chance of preventing pregnancy.

Key Alternatives Explained

Ulipristal acetate (Ella) is a selective progesterone receptor modulator. Unlike levonorgestrel, it can inhibit ovulation even after the luteinising hormone (LH) surge has begun, which is why the effectiveness stays high up to 120hours.

The Yuzpe regimen relies on the combined action of estrogen and progestin. Two doses are required 12hours apart, and the method works mainly by preventing or delaying ovulation. Its main drawback is the higher incidence of nausea and vomiting.

A copper IUD releases copper ions that are toxic to sperm and create a hostile environment for fertilisation. Inserting the device within five days offers >99% effectiveness and provides ongoing contraception for up to ten years.

Mifepristone‑misoprostol regimens act later in the reproductive timeline, interfering with implantation. They are usually reserved for cases where the other options are unavailable or contraindicated.

Side‑Effect Profile at a Glance

• I‑Pill: mild nausea, fatigue, spotting, headache in ~15% of users.
• Ella: occasional abdominal pain, headache, dizziness; lower nausea rates than Yuzpe.
• Yuzpe: higher rates of vomiting (up to 20%) and menstrual irregularities.
• Copper IUD: short‑term cramping, heavier periods, spotting for the first few cycles.
• Mifepristone‑misoprostol: cramping, bleeding, rare allergic reactions.

Comparison Table

Choosing the Right Method for You

Ask yourself these quick questions:

1. How many hours have passed since intercourse? If it’s over 72hours, levonorgestrel loses potency-Ella or a copper IUD become better choices.
2. Do you have a prescription handy? Ella and the copper IUD require a clinician’s approval in the UK.
3. What’s your budget? Over‑the‑counter pills are cheap, but the IUD, while pricey up‑front, saves money long‑term.
4. Are you comfortable with an intra‑uterine device? Some prefer a non‑invasive pill even if it’s slightly less effective.
5. Do you have a history of hormonal side effects? If you’re prone to nausea, the copper IUD may be the gentlest option.

Matching the answers to the table above will usually point you to the most suitable EC.

How to Use Each Option Correctly

I‑Pill: Take the whole tablet as soon as possible. If you vomit within two hours, repeat the dose with a fresh tablet.

Ella: Obtain a prescription, then swallow the single tablet within five days. No need to repeat even if you experience mild nausea.

Yuzpe: Take the first combined pill dose immediately, then the second dose exactly 12hours later. Use a backup barrier method for at least 7days.

Copper IUD: Book an appointment with a qualified clinician. The device is inserted using a sterile speculum; the procedure takes about 5‑10minutes.

Mifepristone‑misoprostol: Follow a clinician’s dosing schedule-usually 200mg mifepristone orally, followed 24‑48hours later by misoprostol tablets.

Potential Pitfalls and How to Avoid Them

• Delaying the I‑Pill beyond 72hours dramatically reduces efficacy; set an alarm.
• Skipping the second Yuzpe dose nullifies protection.
• Attempting self‑insertion of a copper IUD can cause infection-always see a professional.
• Taking Ella without a prescription is illegal in the UK and may lead to counterfeit products.
• Missing the follow‑up appointment after IUD insertion can leave you without proper placement verification.

Cost & Accessibility in the UK (2025)

Over‑the‑counter levonorgestrel pills cost £20‑£30 per pack and are sold in pharmacies without a prescription. Ella still needs a GP or sexual health clinic prescription, and the price sits at £35‑£45. The copper IUD, though pricey (£150‑£200), includes the procedure and long‑term contraception, making it cost‑effective after the first year.

Many sexual‑health clinics offer free or subsidised EC for people under 25 or on low income, so always check local services before buying.