Emergency hormonal contraception
Levonelle, EllaOne
Revisado por Sid DajaniÚltima actualización por Michael Stewart, MRPharmSÚltima actualización 25 Abr 2024
Satisface las necesidades del paciente directrices editoriales
- DescargarDescargar
- Compartir
Emergency hormonal contraception is an emergency 'back-up' to prevent pregnancy in case you have unprotected sex. It is for occasional use. It is not suitable as a regular method of contraception.
The pack contains one tablet - take the tablet as soon as possible.
Use a condom during sex until your next period.
The most commonly reported side-effect is feeling sick (nausea).
En este artículo:
Seguir leyendo
About emergency hormonal contraception
Tipo de medicamento | Emergency contraception ('morning after pill') |
Utilizado para | To prevent pregnancy after unprotected sex |
También llamado | Levonelle® One Step; Levonelle® 1500; Emerres®; Ezinelle®; LoviOne®; Melkine®; Postinor®; Upostelle® (all of which contain levonorgestrel) EllaOne® (which contains ulipristal acetate) |
Disponible como | A tablet |
Emergency hormonal contraception (EHC) is also called the 'morning after pill'. If you have had unprotected sex, taking emergency hormonal contraception within 3-5 days can help prevent pregnancy. The pill should be taken as soon as possible after unprotected sex - the earlier it is taken, the more effective it is. EHC can be used if you have had sex without using contraception, or if you have had sex but there was a mistake with your usual contraception (for example, a split condom or if you forgot to take your usual contraceptive pills).
There are two types of 'morning after pill' available. One contains a medicine called levonorgestrel which is a female progestogen hormone. The other contains a medicine called ulipristal acetate which works on female hormone receptors within your body. They are both thought to work mainly by delaying or stopping your ovaries from releasing an egg.
Although EHC is effective, it is not as reliable as regular planned contraception. Therefore, it should only be used in an emergency.
The levonorgestrel pill is available free on prescription as brands called Levonelle®, LoviOne® and Upostelle®. It can also be purchased from a pharmacy, without a prescription, as a brand called Levonelle® One Step. It is effective for up to 72 hours (three days) after unprotected sex.
The ulipristal acetate pill is effective for up to 120 hours (five days) after having unprotected sex. Ulipristal acetate is available free on prescription through a doctor or family planning clinic as a brand called ellaOne®. It can also be purchased from a pharmacy, without a prescription.
A non-hormonal method of emergency contraception is also available. An intrauterine contraceptive device (IUCD) can be inserted by a doctor or nurse up to five days after unprotected sex. This method of emergency contraception is more effective than hormonal tablets. Your doctor can give you more information about this.
Before taking emergency hormonal contraception
To make sure this is the right treatment for you, before you take the 'morning after pill' it is important that your doctor or pharmacist knows:
If there is a possibility that you could already be pregnant.
Si está en periodo de lactancia.
Si tiene problemas con el funcionamiento del hígado.
If you have severe asthma.
If you have ever had an ectopic pregnancy.
If you have a condition of your small bowel that interferes with the way you absorb food, such as Crohn's disease.
Si padece un raro trastorno sanguíneo hereditario llamado porfiria.
Si alguna vez ha tenido una reacción alérgica a un medicamento.
If you are taking other medicines. This includes any medicines you are taking which are available to buy without a prescription, as well as herbal and complementary medicines. This is important because some medicines reduce the effectiveness of EHC. These include some medicines for epilepsy, two antibiotics called rifampicin and rifabutin, a herbal remedy for low mood, called St John's wort, some medicines used to treat HIV and AIDS, and some medicines taken for indigestion and heartburn.
Seguir leyendo
How to take emergency hormonal contraception
Before you take the tablet, read the manufacturer's printed information leaflet from inside the pack. It will give you more information about the brand of pill you have been given and the side-effects from taking it. Take it exactly as you have been told.
The pack contains one tablet. Take the tablet as soon as possible, as it works better the sooner you take it. Levonorgestrel (called Levonelle®1500, Levonelle® One Step, Upostelle®) is best taken within 12 hours after unprotected sex - do not take it later than 72 hours after unprotected sex unless you have been advised otherwise by a doctor. Ulipristal acetate (ellaOne®) should be taken no later than 120 hours after unprotected sex.
You can take the tablet at any time of day. Although you can take the tablet either before or after food, it is better to have a snack as you take the tablet if possible. This will help to reduce the risk of you feeling sick after taking the tablet. However, don't let this delay you taking the tablet.
If you are sick within three hours of taking the tablet then you should take another tablet as soon as possible. You will need to get a further supply through your doctor or pharmacy.
For some women your doctor may prescribe two levonorgestrel tablets, to be taken together at the same time. This will usually only happen if you are taking certain other medicines that affect how well levonorgestrel works.
Aproveche al máximo su tratamiento
EHC is for occasional use only. It should not be relied upon as a regular method of contraception. Do not use EHC more than once in the same menstrual cycle.
Taking the 'morning after pill' will not provide protection against pregnancy for the rest of your cycle. If you are already using a regular method of contraception such as the contraceptive pill, you should continue to take this at your regular times, although you should also use a condom or avoid having sex until your next period.
Your next period may occur a few days earlier or later than expected. If your periods are delayed by more than about 5-7 days, or if your bleeding is unusual in any way, see your doctor for further advice. Even if you have taken the tablet correctly, there is still a small risk of pregnancy and a pregnancy test may be advised.
If you have any pain in your lower tummy (abdomen) or any unusual vaginal bleeding in the following few weeks, you should see a doctor. These may be signs of an ectopic pregnancy, and although this is rare, it is best to be aware of the possibility as it is a serious condition.
EHC will not protect you against sexually transmitted infections. Speak with your pharmacist, doctor or clinic if you are concerned about this and need advice.
Seguir leyendo
Can emergency hormonal contraception cause problems?
Along with their useful effects, most medicines can cause unwanted side-effects although not everyone experiences them. The table below contains some of the most common side-effects associated with EHC. You will find a full list in the manufacturer's information leaflet supplied with your tablet.
Common side-effects of emergency hormonal contraception (EHC) | ¿Qué puedo hacer si me ocurre esto? |
Sentirse mal (náuseas) o estar enfermo (vómitos) | If you are sick within three hours of taking a tablet then you should take another tablet as soon as possible |
Irregular bleeding before your next period, a light or heavy period, an early or late period | If your periods are delayed by more than 5-7 days, or are unusually light or heavy, see your doctor for further advice |
Pain in your lower tummy (abdomen) | This is often nothing to worry about but if it is severe or if it continues for more than a day or so, see your doctor for further advice |
Feeling tired or dizzy, headache, breast tenderness, diarrhoea, back pain, mood changes | These should pass within a few days |
If you experience other symptoms which you think may be due to the tablet, speak with your doctor or pharmacist for further advice.
How to store emergency hormonal contraception
Mantenga todos los medicamentos fuera del alcance y de la vista de los niños.
Almacenar en un lugar fresco y seco, lejos del calor y la luz directos.
Información importante sobre todos los medicamentos
Información importante sobre todos los medicamentos
Si va a someterse a una operación o a un tratamiento dental, comunique a la persona que vaya a realizar el tratamiento qué medicamentos está tomando.
If you take any medicines that you have bought without a prescription, check with a pharmacist that they are suitable for you to take with your prescribed medicines.
No tome nunca más de la dosis prescrita. Si sospecha que usted u otra persona ha tomado una sobredosis de este medicamento, acuda al servicio de urgencias de su hospital. Llévese el envase, aunque esté vacío.
Este medicamento es para usted. Nunca se lo dé a otras personas aunque su enfermedad parezca ser la misma que la suya.
No guarde medicamentos caducados o que no desee. Llévelos a su farmacia local, que se encargará de eliminarlos por usted.
Si tiene cualquier duda sobre este medicamento pregunte a su farmacéutico.
MHRA - Notificación de reacciones adversas
Notifique a la Agencia Reguladora de Medicamentos y Productos Sanitarios las sospechas de efectos secundarios de medicamentos, vacunas, cigarrillos electrónicos, incidentes con productos sanitarios o productos defectuosos o falsificados para garantizar un uso seguro y eficaz.
Lecturas complementarias y referencias
- Manufacturer's PIL, Levonelle® One Step; Bayer plc, The electronic Medicines Compendium. Dated October 2020.
- Manufacturer's PIL, Ulipristal 30 mg film-coated tablet; Zentiva, The electronic Medicines Compendium. Dated June 2022
- Medicamentos BNF completa 89ª edición; Asociación Médica Británica y Real Sociedad Farmacéutica de Gran Bretaña, Londres.
Historia del artículo
La información de esta página ha sido redactada y revisada por médicos cualificados.
Fecha límite de la próxima revisión: 21 feb 2027
25 Abr 2024 | Última versión

Pregunte, comparta, conecte.
Explore debates, formule preguntas y comparta experiencias sobre cientos de temas de salud.

¿Se encuentra mal?
Evalúe sus síntomas en línea de forma gratuita