What Is Levonorgestrel and How Does It Work?
Levonorgestrel is the active ingredient in emergency contraceptive pills such as Levonelle. It works primarily by delaying or preventing ovulation, which stops an egg from being released and fertilised. It does not terminate an existing pregnancy and is not the same as the abortion pill. For best results, it should be taken as soon as possible after unprotected sex, and it is most effective within 72 hours.
The NHS provides detailed guidance on emergency contraception, including when it can be used and what to expect. If you are unsure whether it is the right option for you, speaking to a pharmacist is a good first step.
Common Levonorgestrel Side Effects to Be Aware Of
Most levonorgestrel side effects are mild and short-lived, typically resolving within a few days. The most frequently reported effects are related to hormonal changes in the body and are not a cause for concern in most cases.
| Side Effect | How Common | How Long Does It Typically Last |
|---|---|---|
| Nausea | Very common | A few hours to one day |
| Headache | Common | A few hours to one day |
| Fatigue or dizziness | Common | A few hours |
| Abdominal pain or cramps | Common | One to two days |
| Irregular bleeding or spotting | Common | Until your next period |
| Breast tenderness | Less common | A few days |
| Vomiting | Less common | A few hours |
How Levonorgestrel Can Affect Your Next Period
One of the most commonly reported effects of levonorgestrel is a change to your menstrual cycle. Your next period may arrive earlier or later than expected, and it may be heavier, lighter, or more irregular than usual. This is a normal hormonal response to the medication and not a sign that something has gone wrong. However, if your period is more than five to seven days late after taking levonorgestrel, it is advisable to take a pregnancy test to rule out pregnancy.
Spotting or light bleeding in the days following the pill is also common and does not indicate that the medication has failed. If you are concerned about any changes to your cycle, our team at King’s Pharmacy is happy to provide reassurance and guidance.
What to Do If You Vomit After Taking Levonorgestrel
If you vomit within 2-3 hours of taking levonorgestrel, the pill may not have been fully absorbed, and you should take another dose as soon as possible. Contact your pharmacist or GP to obtain a replacement dose promptly, as time is an important factor in the effectiveness of emergency contraception. If vomiting is a concern for you, your pharmacist may be able to advise on anti-sickness options.
Serious Levonorgestrel Side Effects and When to Seek Medical Advice
Serious side effects from levonorgestrel are rare, but there are some situations where you should seek medical attention promptly. These include severe abdominal pain, which can, in rare cases, indicate an ectopic pregnancy, particularly if you have missed a period or have had a previous ectopic pregnancy. You should also seek advice if you experience an allergic reaction, such as rash, swelling, or difficulty breathing, after taking the pill.
If you are on regular medication, it is important to check with a pharmacist before taking levonorgestrel, as certain medicines, including some epilepsy drugs, HIV treatments, and St John’s Wort, can reduce its effectiveness.
Curious about the pricing? Read our detailed guide on how much a contraceptive pill costs in Birmingham for more details.
Get Contraception Advice at King’s Pharmacy Birmingham
If you have taken levonorgestrel and are concerned about side effects, or if you need confidential advice on emergency contraception in Birmingham, our pharmacy team is here to help. We offer a discreet, non-judgmental service and can advise on all contraceptive options available to you.
If you have questions about levonorgestrel or any other contraception, contact the King’s Pharmacy team today or find out more about our Birmingham health clinics.
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Frequently Asked Questions
How long do Levonorgestrel side effects last?
Most side effects, such as nausea, headache, fatigue, and dizziness, resolve within 24 hours of taking the pill. Changes to your menstrual cycle, including spotting or an altered period, may last until your next period arrives. If symptoms are persistent or worsening after a few days, speak to a pharmacist or GP for further advice.
Is it normal to bleed after taking levonorgestrel?
Yes. Light spotting or irregular bleeding in the days following levonorgestrel is common and is caused by the hormonal shift triggered by the medication. It does not mean the pill has failed or that anything is wrong. However, if your next period is more than five to seven days late, take a pregnancy test to be sure.
Can Levonorgestrel make you feel sick?
Nausea is one of the most commonly reported side effects of levonorgestrel. Taking the pill with food can help to reduce the likelihood of feeling sick. If you do vomit within 2-3 hours of taking it, you will need a replacement dose as the medication may not have been properly absorbed. Contact King’s Pharmacy or your GP promptly if this happens.
Does levonorgestrel affect future fertility?
No. Levonorgestrel does not affect your long-term fertility. Once the hormone clears your system, your fertility returns to normal. It is also worth noting that levonorgestrel does not provide ongoing contraceptive protection, so it is important to use regular contraception going forward if needed. Our team at King’s Pharmacy in Birmingham can advise on suitable options.
Can you take Levonorgestrel more than once?
Yes, levonorgestrel can be taken more than once, including within the same menstrual cycle if necessary. However, it is not intended to be used as a regular form of contraception due to its higher hormone dose and reduced reliability compared to long-term methods. If you find yourself needing emergency contraception frequently, speak to a pharmacist about ongoing contraceptive options that may be better suited to your needs.