Is the Levonelle Pill Less Effective for Some People?

The Levonelle pill is one of the most well-known forms of emergency contraception available in the UK. Used to help prevent pregnancy after unprotected sex or contraceptive failure, it’s a reliable and accessible option – but it’s not a one-size-fits-all solution.

At Junction Pharmacy, we regularly advise patients on their emergency contraception options, including Levonelle and ellaOne. One of the most common concerns people have is whether these pills work the same for everyone. In this article, we’ll look at key factors that may impact the effectiveness of the Levonelle pill and what you can do to make sure you’re using the right product for your needs.

How the Levonelle Pill Works

Levonelle contains a synthetic hormone called levonorgestrel, which works by delaying or preventing ovulation. If ovulation hasn’t yet occurred, Levonelle reduces the chance of sperm meeting an egg, thereby preventing pregnancy.

To be most effective, Levonelle should be taken within 72 hours (3 days) after unprotected sex. The sooner it’s taken, the more effective it is, ideally within the first 12 to 24 hours.

1. Timing Makes a Difference

Timing is one of the most critical factors when it comes to the effectiveness of the Levonelle pill. Although it’s licensed for use up to 72 hours after unprotected sex, its effectiveness decreases as time passes.

• Within 24 hours: Around 95% effective

• 24 to 48 hours: Around 85% effective

• 48 to 72 hours: Around 58% effective

If more than 72 hours have passed, Levonelle is no longer the recommended option, and you may be better suited to ellaOne (effective for up to 120 hours) or a copper IUD, which can be fitted at some sexual health clinics.

At Junction Pharmacy, we’ll ask you when you last had unprotected sex so we can advise on which emergency contraceptive is most suitable based on time alone.

2. Weight and BMI Can Impact Effectiveness

One factor that many people aren’t aware of is the potential effect of body weight on how well the Levonelle pill works.

Some studies suggest that Levonelle may be less effective in people with a higher body mass index (BMI), particularly over 26, or those weighing more than 70kg. The medication’s concentration in the bloodstream may be lower in individuals with a higher body weight, which could reduce its ability to prevent ovulation.

That doesn’t mean Levonelle is completely ineffective for people above that threshold — but the evidence does point to a reduction in effectiveness.

In these cases, ellaOne may be a better option, as research shows it maintains its effectiveness across a broader weight range. However, like any medication, ellaOne also has its own considerations, including potential interactions and contraindications.

If you’re unsure which pill is best for you, our team at Junction Pharmacy can help you make an informed choice confidentially and without judgement.

3. Interactions with Other Medications

Certain medicines can interfere with how well Levonelle works. These include:

• –> Some epilepsy medicines, such as carbamazepine and phenytoin

• –> Rifampicin, an antibiotic used for TB and meningitis

• –> St John’s Wort, a herbal remedy for low mood

• –> Some treatments for HIV

These medications may speed up the breakdown of levonorgestrel in the body, meaning the Levonelle pill may not work as intended. If you’re taking any of these or aren’t sure about potential interactions, speak with our pharmacists before taking Levonelle.

In some situations, a double dose of Levonelle may be recommended, or you may be advised to use ellaOne or a copper IUD instead.

4. Vomiting or Severe Diarrhoea

Although uncommon, if you vomit within 3 hours of taking Levonelle, there’s a chance the medication hasn’t been absorbed properly, which could reduce its effectiveness. You’ll need to take another dose as soon as possible.

Similarly, severe diarrhoea may interfere with absorption and impact how well the medication works.

Our pharmacy team is always on hand to answer your questions and help determine whether a second dose is needed.

Stocked Options at Junction Pharmacy

We know that time is of the essence when it comes to emergency contraception. That’s why we stock both the Levonelle pill and ellaOne, making it easy for you to access the treatment you need quickly and discreetly.

You don’t need a GP appointment, just visit us in-store or call ahead to check stock and availability. We offer private consultations in a calm, confidential setting to help you feel comfortable and supported throughout the process.

Access the Solution You Need

The Levonelle pill is a safe and effective emergency contraceptive, but its success depends on several personal factors, including timing, weight, and any medications you’re currently taking. At Junction Pharmacy, we’re here to guide you through the decision-making process and ensure you leave with the right solution for your needs.

If Levonelle isn’t suitable for you, we can offer ellaOne as an alternative or help direct you to a clinic that provides copper IUDs.

Need emergency contraception? Don’t wait, contact Junction Pharmacy or drop in for advice and access to the Levonelle pill or ellaOne today.

This blog was written on behalf of Junction Pharmacy by Pharmacy Mentor.