EllaOne side effects are usually mild and short-lived: headache, nausea and abdominal pain are reported most often, and your period can shift by a few days. EllaOne is an emergency contraceptive pill that can be used up to 120 hours, or five days, after unprotected sex. What many women do not know is that this medicine and hormonal contraception can work against each other in both directions. That is exactly where things most often go wrong in practice.
What is EllaOne and how does it work?
EllaOne contains 30 mg of ulipristal acetate. It is not a hormone like the one in the pill, but a substance that temporarily blocks the action of progesterone on the ovary. That delays your ovulation.
That delay is the entire mechanism. Sperm can survive for several days in your body. If ovulation is pushed beyond that window, there is no egg to fertilise. Research in Human Reproduction (2010) showed that ulipristal could still delay follicular rupture when given just before ovulation, at a point where levonorgestrel no longer manages it.
From that follows the key limitation: if ovulation has already happened, EllaOne has nothing left to delay. It also does not interrupt an existing pregnancy. That is a medical distinction, not a detail.
EllaOne compared with the other options
There are three routes for emergency contraception in the Netherlands, and they differ considerably in how long they remain usable and how reliable they are:
| Option | Active substance | Usable up to | Prescription needed? | Point to consider |
|---|---|---|---|---|
| EllaOne | Ulipristal acetate 30 mg | 120 hours (5 days) | No, via the pharmacy | Still works just before ovulation |
| Levonorgestrel morning-after pill | Levonorgestrel 1.5 mg | 72 hours (3 days) | No, via the pharmacy | Loses effectiveness faster after 72 hours |
| Copper coil | Copper, no hormone | 120 hours (5 days) | Yes, fitted by a doctor | The most reliable option, and stays as contraception |
In a randomised study in The Lancet (2010) the pregnancy rate within 72 hours was 1.8 percent with ulipristal against 2.6 percent with levonorgestrel. These details also come from the patient leaflet and the Dutch Farmacotherapeutisch Kompas.
EllaOne experiences: what do users say?
Experiences with EllaOne are rarely about taking it, because that is one tablet. They are almost always about the weeks afterwards: when will my period come, and is it normal that I feel different? These are the experiences shared most often.
What women find helpful: the five-day window instead of three, availability at the pharmacy without a prescription, a single dose with or without food, and barely noticeable side effects for many women.
Points women mention: headache and nausea in the first days, a period arriving several days earlier or later than expected, spotting that can be confusing, uncertainty about whether it worked, and confusion about when the pill becomes reliable again.
Picture two women who take EllaOne on the same day. One gets her period three days early and assumes something is wrong, when that is a known and harmless effect. The other is a week late, stays stuck in uncertainty, and eventually has her hCG measured for a definitive answer. The same medicine, a very different experience.
Side effects of EllaOne
Most side effects of EllaOne are mild and settle within a few days. Commonly reported are headache, nausea, abdominal pain, period pain, tiredness, dizziness and mood changes.
A shift in your cycle is not a side effect in the narrow sense but part of how it works: your ovulation is delayed, so your period moves with it. It usually arrives within a week of the expected date. If you vomit within three hours of taking it, there is a good chance it was not absorbed, so checking with the pharmacy or your doctor is sensible.
Contact a doctor about severe or persistent abdominal pain in the weeks afterwards, particularly if your period does not arrive. That can also point to a pregnancy outside the womb, which is rare but needs prompt assessment.
Benefits and points to consider
The clearest benefit of EllaOne is the five-day window and the fact that it still works just before ovulation, precisely in the days when the chance of pregnancy is highest.
There are two points that are rarely explained well. The first is the interaction with hormonal contraception, and it runs both ways. If you used a progestogen in the days beforehand, such as the pill or the mini-pill, that can reduce how well ulipristal works. And in the other direction, ulipristal can disturb the reliability of your pill. This is why the leaflet advises waiting five days after EllaOne before starting or restarting hormonal contraception, and using condoms during that time and the following week.
The second point is body weight. An analysis of the randomised trials (Contraception, 2011) showed the chance of pregnancy despite emergency contraception was more than three times higher in women with obesity than at a normal weight, with levonorgestrel falling short sooner than ulipristal at higher weights. For anyone wanting certainty on this, the copper coil is the most reliable option.
Alternatives to EllaOne
Which option fits best depends mainly on how much time has passed and where you are in your cycle.
- The levonorgestrel morning-after pill, usable up to 72 hours and without the waiting period before resuming the pill
- The copper coil, which can be fitted up to five days later and then continues as long-term contraception
- Thinking about regular contraception? Read about the mini-pill with desogestrel or experiences with the Yasmin pill
When an hCG blood test gives clarity
The hardest part after emergency contraception is the waiting. A home urine test only becomes reliable from around the time your period was due, and a faint line sometimes makes the uncertainty worse rather than better.
A blood test measures the exact amount of hCG and can confirm a pregnancy earlier than most urine tests, from roughly 8 to 10 days after conception. You get a number rather than a line. If your period stays away for more than a week, or a home test gave an unclear result, the hCG blood test from Lunara gives an answer, with an assessment by a BIG-registered doctor. Want to know what a measured value means? Read about hCG levels in early pregnancy and about hCG doubling time.
Frequently asked questions
How long does EllaOne work?
EllaOne can be taken up to 120 hours, or five days, after unprotected sex. It works best the sooner you take it, so waiting offers no advantage.
When does your period come after EllaOne?
Usually within a week of the expected date, slightly earlier or slightly later. If you are more than seven days late, a pregnancy test is sensible.
When can you restart the pill after EllaOne?
The leaflet advises waiting five days before starting or restarting hormonal contraception, because ulipristal and progestogens can disturb each other. Use condoms during that time and the week after.
Does EllaOne work less well at a higher weight?
Analyses of the trial data suggest emergency contraception is less reliable at higher body weight, with ulipristal holding up longer than levonorgestrel. If you want maximum certainty, discuss the copper coil.
Can you use EllaOne more than once in a cycle?
Repeated use within the same cycle is not recommended and has not been studied as a method. Emergency contraception is meant for exceptions; if it happens often, discuss a regular method with your GP.
EllaOne gives you five days instead of three, and in emergency contraception that is a real difference. Pay particular attention to the waiting period before resuming hormonal contraception, because that is where things most often go wrong. And if uncertainty lingers, do not wait longer than you need to for an answer.
Every blood test result includes a professional assessment from a BIG-registered doctor. For treatment decisions, discuss your results with your GP.
References
- Farmacotherapeutisch Kompas. Ulipristal. Accessed 2026.
- Thuisarts.nl. Emergency contraception. Accessed 2026.
- Glasier AF, et al. Ulipristal acetate versus levonorgestrel for emergency contraception: a randomised non-inferiority trial and meta-analysis. The Lancet, 2010. PMID 20116841.
- Glasier A, et al. Can we identify women at risk of pregnancy despite using emergency contraception? Data from randomized trials of ulipristal acetate and levonorgestrel. Contraception, 2011. PMID 21920190.
- Brache V, et al. Immediate pre-ovulatory administration of 30 mg ulipristal acetate significantly delays follicular rupture. Human Reproduction, 2010. PMID 20634186.
- McKeage K, Croxtall JD. Ulipristal acetate: a review of its use in emergency contraception. Drugs, 2011. PMID 21568368.
Author
Lunarahealth
Dr. Naimi, BIG-registered physician, oversees the medical standards behind our content and assessments. Read our medical policy
