Ask An Adult: How Does The Morning After Pill Work?
The Debrief: We all know that the morning after pill can be used to prevent pregnancy following unprotected sex – but how does it work, how reliable is it and how do you know if it’s working? So many questions, so we’ve asked several experts to explain…
How exactly does the morning after pill work? How do you know if the morning after pill has worked?
‘The Morning after pill works by delaying ovulation, the monthly release of an egg from your ovaries,’ explains consultant gynecologist Diana Mansour. ‘Once the egg is released from your ovary, it travels down the fallopian tube towards the womb. Fertilisation happens if sperm meets and fuses with the egg. If you have sex around the time of ovulation, sperm sits around in the cervix and top part of your vagina for 5-7 days. So, by delaying ovulation, there’ll be no egg available to be fertilised until after the sperm have gone, hence pregnancy cannot occur.’
How do you know the morning after pill has worked?
In theory, during the average woman’s cycle there are six days when sex can result in pregnancy. This time is known as the ‘fertile window’. Since the timing of ovulation is unpredictable, you have no way of knowing when your fertile window is – and it can be at a different time every month. This means you’re at risk of pregnancy throughout almost the whole of your menstrual cycle.
So how reliable is the morning after pill? Is the morning after pill 100% effective?
Despite this, the morning after pill is still a very effective form of emergency contraception. ‘The overall failure rate is about 2%, but the sooner you take it the more effective it is,’ says Sue Knight, a lead nurse at sexual health charity Brook.
Is there anything else you can do to improve your chances of not getting pregnant?
‘We do always tell women about using the emergency coil (IUD) – that’s over 99% effective so it’s the most effective method of preventing an unintended pregnancy,’ Sue adds.
As Diana Mansour explains, ‘The copper IUD prevents implantation of a fertilised egg. Its failure rate is about one in a thousand.’
Can you use the coil and morning after pill together?
Yes, and this is a great way of backing up your emergency contraception. ‘We’d tend to give the emergency contraceptive pill first,’ says Sue. ‘Then, if there wasn’t a doctor or specialist nurse on duty to fit the coil there and then, we’d book the person in as soon as possible for the coil fit if they want that as well.’
When can you take the morning after pill?
It should be taken as soon as possible to give the best chance of avoiding pregnancy.
However, despite being commonly known as ‘the morning after pill’, you can take the emergency contraceptive pill up to five days after unprotected sex.
‘One of the morning after pills can be taken up to five days after unprotected sex,’ explains Clare Murphy from the British Pregnancy Advisory Service (BPAS).
What’s the difference between the two different types of morning after pill?
There are different types of morning after pill; some contain levonorgestrel, a synthetic version of progestrogen. ‘It’s very much like the progestrogen-only pill, but in a higher dose,’ Diana explains. Another contains ulipristal acetate, which prevents progestrogen from working normally.
If you’re not sure, discuss your options with your healthcare professional – whether it’s your doctor, nurse or pharmacist. They can advise you on the different dosages available and how effective they’ll be.
Does anything else make the morning after pill less effective?
The morning after pill can interact with certain anti-epileptic medications, and herbal medications such as St John’s Wort, so it’s really important to discuss what other medications you’re taking with the pharmacist or healthcare professional.
How can you tell if the morning after pill has worked?
‘Your period will normally come when you’re expecting it, plus or minus a couple of days. However, it might be delayed up to seven days from when you’re expecting it,’ Diana says. ‘For about one in five women it will be delayed, so don’t get too panicked, but if you’re more than seven days late, think about seeing a doctor or nurse, or get a pregnancy test.’
She adds: ‘If it doesn’t work but you decide to keep the pregnancy, we’ve got no evidence that either of the emergency contraceptive pills have an effect on the baby.’
Otherwise, that’s certainly the time to go and have a chat with your GP, or one of the local sexual health services, about other options.
Where can you get the morning after pill?
‘Emergency contraception is available free of charge from Brook clinics, GPs, contraception and sexual health clinics,’ says Sue. It’s also available over the counter from pharmacies and, Clare says, ‘Lots of pharmacies now have an arrangement with the local NHS service to supply it free of charge to women of a certain age, often up to 25, so most areas have that kind of scheme in place.’
She adds: ‘It’s not always necessary for you to have to pay for the morning after pill. There’s usually lots of information on your local NHS website about which stores will provide it for free.’
Can you stock up on the morning after pill in advance?
The morning after pill is for occasional use only and should not be seen as a replacement for regular contraceptive methods. It should be seen more as a back-up.
However, it may be sensible to have an emergency contraceptive pill at home just in case, for those rare occasions.
Is the morning after pill free? - When/where can it be purchased for free?
You can buy the morning after pill over the counter from pharmacies, but you can also get the morning after people for free from contraception clinics, Brook centres, some pharmacies and most sexual health clinics. You can also get them from most NHS walk-in centres or urgent care centres, most GP surgeries and some A&E departments.
Can you stock up on the morning after pill for free
‘It can be given [free of charge] in advance for certain situations, for example if you’re going away on holiday,’ says Sue. ‘You could also purchase it in advance,’ she adds.
BPAS would like to see the availability of advanced supply extended. ‘We know lots of women rely on condoms as their main form of contraception, but the fact is condoms do come off,’ says Clare. ‘We think it would make absolute sense for women to be able to keep a pack of emergency contraception at home, because the sooner you can take it the better.’
Women should be advised to adopt a regular method of contraception.
What are the side effects of the morning after pill?
‘This is a medication that’s been around for over a decade, it’s generally well tolerated, and you can take it as and when needed. However, it shouldn’t be seen as a regular method of contraception. Obviously, if you find yourself taking it more than just occasionally, it would make sense to consider a more regular form of contraception and speak to a healthcare professional about the options available’, says Clare.
‘I think there’s a narrative around emergency contraception, that it’s a “dirty girl’s drug”, a marker of irresponsibility – but we feel that having it in your cupboard, in recognition that things don’t always go according to plan, is actually a real marker of responsibility.’
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