Emergency contraception timing after unprotected sex matters because the options do not all have the same time window, and the number of hours that have passed is only part of the assessment. In the UK, levonorgestrel emergency contraception is licensed for use within 72 hours, while ulipristal acetate can be used up to 120 hours. A copper intrauterine device (IUD) is the most effective method of emergency contraception and can sometimes remain an option when oral emergency contraception is no longer suitable.
The practical message is to seek advice as soon as you can rather than waiting for a deadline. Ovulation is difficult to predict precisely, oral emergency contraception works by delaying ovulation, and factors such as earlier episodes of unprotected sex, missed contraception, medicines and body weight can affect which option is appropriate. This guide explains how the choices change as time passes without turning the article into a substitute for an individual clinical assessment.
Quick answer: what changes as the hours pass?
The sections below are a timing guide, not a self-selection tool. A pharmacist, GP or sexual health clinician should assess the full situation, including when sex happened, where you may be in your cycle, any contraception that was missed or used incorrectly, medicines you take and whether there have been several episodes of unprotected sex.
Why the clock is not the whole story
Oral emergency contraception mainly works by delaying ovulation. FSRH guidance states that the available evidence suggests oral emergency contraception is ineffective after ovulation has already taken place. The difficulty is that most people cannot know the exact day or hour of ovulation from a calendar or app, and cycle timing can vary.
That is why a simple rule such as “I still have two days left” can be misleading. The formal 72-hour and 120-hour limits matter, but the best option also depends on biological timing and individual circumstances. The copper IUD is different: FSRH describes it as the most effective method of emergency contraception and the only emergency method that is effective after ovulation, provided it can be inserted within the appropriate clinical window.
During the first 72 hours
Within the first 72 hours, both levonorgestrel and ulipristal acetate are within their licensed emergency-contraception windows. NHS guidance advises using emergency contraception as soon as possible. FSRH also states that ulipristal acetate has been demonstrated to be more effective than levonorgestrel from 0 to 120 hours after unprotected sexual intercourse, although the most appropriate option still depends on the individual assessment.
This is an important correction to overly simple advice that treats the first 24 hours as a universal ‘best period’ for every oral option. Earlier access is still sensible because the risk of ovulation and loss of options increases with delay, but the evidence for ulipristal acetate is not accurately described by saying its effectiveness simply falls hour by hour across the whole 120-hour window.
Between 72 and 120 hours
Once 72 hours have passed, levonorgestrel is outside its UK licensed time window. Ulipristal acetate remains licensed up to 120 hours, and FSRH says it is the only oral emergency contraception likely to be effective when the episode occurred 96 to 120 hours ago. A copper IUD may also be considered and remains the most effective emergency-contraception method.
If you want a clearer comparison of the methods themselves rather than the clock alone, read our guide to emergency contraception options: pill versus copper IUD. It explains the different roles of oral emergency contraception and the copper IUD while keeping the timing decision with a clinician.
If more than five days have passed
More than 120 hours after the last episode of unprotected sex, oral emergency contraception is unlikely to be effective. That does not always mean there is nothing to discuss. FSRH guidance allows a copper IUD to be inserted for emergency contraception within five days after the first episode of unprotected sex in a cycle, or within five days of the earliest estimated date of ovulation, whichever is later. This requires clinical assessment; it is not a calculation to make on your own.
If you are unsure exactly when sex happened, your cycle is irregular, or there have been several episodes, contact a pharmacy, GP or sexual health service rather than assuming you are either safely inside or definitely outside a treatment window.
If your main concern is that the pill was already taken later than intended, the separate article on what happens if the morning after pill is taken late covers delayed-use concerns and what to do next without duplicating this page’s full timing-window explanation.
If there has been more than one episode of unprotected sex
The timing does not simply reset from the most recent episode. A clinician needs to consider all episodes in the current cycle because an earlier episode may change pregnancy risk, the usefulness of a pregnancy test and whether a copper IUD can be used. FSRH guidance also notes that oral emergency contraception can sometimes be used more than once in the same cycle if there is further unprotected sex, but the choice can be affected by which emergency pill was used previously and by recent progestogen exposure.
For that reason, give the pharmacist or clinician the dates and approximate times of every relevant episode, not only the latest one. Also explain whether regular contraception was missed, delayed, vomited, removed or otherwise compromised.
Timing after taking the emergency contraceptive pill
Oral emergency contraception does not provide ongoing protection for sex later in the cycle. FSRH advises that there is a new pregnancy risk if further unprotected sex occurs and ovulation then happens later in the same cycle. After levonorgestrel, suitable hormonal contraception can usually be started immediately. After ulipristal acetate, FSRH generally advises waiting five days before starting or restarting hormonal contraception, then using condoms or avoiding sex until the chosen method becomes effective.
The exact backup period depends on the contraceptive method, so follow the instructions given by the pharmacist or clinician rather than using a generic number of days. FSRH also advises pregnancy testing 21 days after the last episode of unprotected sex; a pregnancy test is also recommended if the next period is more than seven days late after emergency contraception.
Getting emergency contraception support in Chingford
Mount Pharmacy at 80 Chingford Mount Road is currently listed on the NHS as providing contraception services. Its NHS profile lists the NHS Pharmacy Contraception Service, including free oral emergency contraception, and notes that booking may be needed. The same NHS profile also lists a paid emergency-contraception service for people aged 16 or over. If you need local assessment, see the emergency contraception service at Mount Pharmacy for contact and service information. A pharmacist will assess suitability; oral emergency contraception is not guaranteed, and copper-IUD fitting requires a suitably trained service.
What information should you have ready?
A good emergency-contraception assessment is based on more than one question about time. If possible, be ready to tell the pharmacist or clinician:
- the date and approximate time of each episode of unprotected sex or contraceptive failure;
- the first day of your last period and whether your cycles are usually regular;
- what regular contraception you use and what went wrong, such as missed pills or a condom failure;
- whether you have already used emergency contraception during this cycle;
- which prescribed medicines, over-the-counter medicines, herbal products or supplements you use;
- whether you are breastfeeding or could already be pregnant; and
- any other health information the clinician asks for, including weight or BMI where relevant to choosing oral emergency contraception.
Do not delay asking for help because you do not know every answer. An approximate timeline is more useful than waiting while the emergency-contraception window becomes narrower.
Conclusion
Emergency contraception timing after unprotected sex is not a single countdown. Levonorgestrel has a 72-hour licensed window, ulipristal acetate can be used up to 120 hours, and the copper IUD is the most effective method and may sometimes remain possible based on ovulation timing. The safest practical approach is to seek assessment promptly, give the clinician the full timeline and avoid assuming that a calendar or app can tell you which option is suitable.
If you are in Chingford and want local advice, Mount Pharmacy can assess oral emergency-contraception options and signpost to a service that can fit a copper IUD when appropriate. Supply is subject to clinical suitability and current service availability.
Frequently asked questions
Is the morning after pill only useful the next morning?
No. The term “morning after pill” can be misleading. Levonorgestrel is licensed for use within 72 hours after sex and ulipristal acetate within 120 hours. You should still seek help as soon as possible because timing relative to ovulation and other factors affect which option is appropriate.
Can I still use emergency contraception after three days?
Possibly. Ulipristal acetate can be used up to 120 hours after sex, and a copper IUD may also be an option. Levonorgestrel is licensed only up to 72 hours. A clinician should assess the full timeline rather than choosing solely from the number of hours.
What if more than five days have passed?
Oral emergency contraception is unlikely to be effective more than 120 hours after the last episode of unprotected sex. A copper IUD can sometimes still be used if the clinical timing in relation to ovulation allows it, so contact a sexual health service, GP or pharmacy for advice rather than assuming there are no options.
Does the emergency contraceptive pill protect me if I have sex again?
No. Oral emergency contraception does not provide ongoing contraception. Further unprotected sex later in the same cycle can create a new pregnancy risk. Ask the pharmacist or clinician when to start or restart regular contraception and how long to use additional precautions.
When should I take a pregnancy test after emergency contraception?
FSRH guidance advises a pregnancy test 21 days after the last episode of unprotected sex. You should also test and seek advice if your next period is more than seven days late, or if you have other pregnancy concerns.
Can Mount Pharmacy fit a copper IUD for emergency contraception?
The current NHS profile for Mount Pharmacy confirms emergency-contraception services but does not list copper IUD fitting at the pharmacy. The profile states that the pharmacy can advise where to obtain an IUD. IUD insertion requires a suitably trained clinician, commonly through a sexual health clinic or some GP services.
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Mount Pharmacy
Clinical information sources
- NHS – Emergency contraception
- NHS – How to take the emergency contraceptive pill
- FSRH – Emergency Contraception Guideline (amended July 2023)
- NHS England – NHS Pharmacy Contraception Service, version 3.0
- NHS – Mount Pharmacy contraception services profile
Important information
This page provides general information and does not replace an individual consultation. Emergency contraception is not suitable for everyone, and the most appropriate option depends on timing, menstrual-cycle factors, medicines, regular contraception and other clinical information. Booking, availability and supply can change, and a consultation does not guarantee that an emergency contraceptive pill will be supplied. If you need a copper IUD, you will need a service with a suitably trained IUD fitter.
