Morning-After Pill in Hong Kong: Plan B, Ulipristal and the Copper IUD

A condom splits. A pill gets missed. Sex happens without protection. What follows is mostly a timing question: how long do I have before this stops working? The Family Planning Association of Hong Kong (FPAHK) calls these tablets 緊急避孕丸, and its guidance sets short windows much like the NHS does.

Three options exist. Two are single tablets, levonorgestrel and ulipristal acetate, and the third is the copper IUD, a small device that a clinician fits. All three work better the sooner they are used, and the coil is the most effective of them (NHS). The tablets cover one act of sex, not the rest of the month.

In short

• Levonorgestrel works up to 72 hours after sex, ulipristal acetate up to 120 hours, and a copper IUD can be fitted within 5 days (NHS).
• Sooner is better. Levonorgestrel's efficacy falls as time passes, so take it as soon as you can.
• Body weight and enzyme-inducing medicines can change which pill fits best; the copper IUD is affected by neither.
• Restart regular contraception in the way that suits the tablet you took, and test for pregnancy if your period is 5 to 7 days late or more.

Which emergency contraception options exist, and how long do you have?

If you are reading this with a split condom already in the bin, the first thing you need is the shape of the window you are standing in. Levonorgestrel is a single 1.5 mg tablet for use within 72 hours of unprotected sex. Ulipristal acetate is a single 30 mg tablet with a longer reach, up to 120 hours, and the FPAHK says its efficacy is the same across that window. A copper IUD is fitted within 5 days and is the most effective of the three; the Family Planning Association of Hong Kong records a failure rate of 0.09% for it (FPAHK).

The coil has a second use. Once fitted, it can stay in as your regular contraception for 5 or 10 years, depending on the type (NHS). That suits someone who wants long-term cover as well. A trained nurse or doctor fits it, usually after an appointment.

The pill percentages come from different trials with different designs, so read them as rough ranges rather than a direct league table.

How well does each one work?

None of the three is a guarantee. Research cited by the NHS suggests that around 1 to 2 women in every 100 who take an emergency pill still become pregnant (NHS). WHO puts the pregnancy rate at 1.2% for ulipristal and 1.2% to 2.1% for levonorgestrel, and notes that ulipristal is the more effective of the two pills when sex was between 72 and 120 hours ago (WHO).

Timing matters most with levonorgestrel. Its SmPC says to take the tablet as soon as possible, preferably within 12 hours and no later than 72 hours. In a 1998 trial of the older two-dose regimen, levonorgestrel prevented 95% of expected pregnancies when taken on day 1, 85% on day 2 and 58% on day 3; pooled across studies, the pregnancy rate was 1.01% against roughly 8% expected without emergency contraception (Levonelle SmPC).

Ulipristal keeps its efficacy across the 120 hours. In pooled trials of women treated within 72 hours, pregnancy rates were 1.36% with ulipristal and 2.15% with levonorgestrel, and in an open-label study of women who started 48 to 120 hours after sex, 2.1% became pregnant (ulipristal SmPC). The FPAHK reads the evidence the same way: levonorgestrel loses efficacy as time passes, while ulipristal does not within its 120-hour window (FPAHK).

Does body weight or other medicines change which pill to use?

Both SmPCs describe the data on weight and BMI as limited and inconclusive and say the tablet should be taken as soon as possible whatever you weigh (Levonelle SmPC; ulipristal SmPC). The FPAHK's comparison table is more definite: it does not recommend levonorgestrel above 70 kg or a BMI above 26, and says ulipristal's efficacy is not affected by weight (FPAHK). A pharmacokinetic study found levonorgestrel levels about half as high in women with a BMI of 30 or more, and doubling the dose to 3 mg brought those levels into line with normal-weight women on 1.5 mg, though the SmPC says the clinical relevance is unclear (Levonelle SmPC).

Some medicines speed up the liver enzymes that clear these hormones, leaving less of the drug working. The SmPCs name efavirenz, rifampicin, rifabutin, carbamazepine, phenytoin, barbiturates, ritonavir, griseofulvin and St John's wort, and they count use within the past four weeks (Levonelle SmPC; ulipristal SmPC). If one of those applies to you, the SmPCs point to a copper IUD first. For women who cannot or do not want an IUD, the levonorgestrel SmPC lists a double dose, two 1.5 mg tablets together within 72 hours, as an option, and says this exact combination has not been studied. That is the label's wording, not a dose to work out alone. The ulipristal SmPC does not recommend ulipristal with these medicines.

The NHS says to ask for advice first if you take medicines for TB, epilepsy or HIV, or griseofulvin or St John's wort, since an IUD may be advised instead (NHS). The ulipristal SmPC also does not recommend ulipristal for severe asthma treated with oral steroids (ulipristal SmPC). A pharmacist or clinic can confirm which option fits your situation.

What happens in the days after taking it?

You swallow the tablet and then nothing obvious happens. Side effects are mostly mild and short. The FPAHK lists headache, nausea, dizziness, tiredness, period-like cramps, abdominal and back pain and breast tenderness, and says they generally do not last more than 24 hours (FPAHK). The levonorgestrel SmPC adds diarrhoea, vomiting and irregular bleeding.

If you vomit within 3 hours of a tablet, both SmPCs say another tablet should be taken (Levonelle SmPC; ulipristal SmPC). The NHS page gives 2 hours and suggests asking a pharmacist (NHS), so the longer window is the safer one to go by.

Your next period is the main thing to watch. After levonorgestrel, most women get it within 5 to 7 days of the expected date (Levonelle SmPC). After ulipristal, 74.6% of women had their period within 7 days of when they expected it, and 18.5% had it more than 7 days late (ulipristal SmPC). The levonorgestrel SmPC says bleeding patterns may be temporarily disturbed.

If you are breastfeeding, the FPAHK says levonorgestrel can be used. Its SmPC suggests feeding first and then skipping nursing for 8 hours (Levonelle SmPC), and the NHS says the pill can be used while breastfeeding (NHS). Ulipristal is different: breastfeeding should be avoided for 7 days (FPAHK; ulipristal SmPC).

These tablets work by stopping or delaying ovulation. Once a pregnancy has implanted they are no longer effective and will not cause an abortion (WHO; FPAHK).

How do you restart regular contraception, and when should you test for pregnancy?

A single tablet covers a single act of sex. It gives you no protection for anything afterwards, which is where the next decision starts (FPAHK).

What you do next depends on which tablet you took. After levonorgestrel, WHO says you can resume or start any contraception method straight away, including a copper IUD (WHO). After ulipristal, WHO says to start a progestogen-containing method on the sixth day, and the ulipristal SmPC says it may reduce the action of hormonal contraceptives (WHO; ulipristal SmPC). The Levonelle One Step SmPC advises using a barrier method such as a condom until your next period (Levonelle One Step SmPC). The two emergency pills are not used together in one cycle (FPAHK). If a copper IUD was fitted, no further contraception is needed (WHO).

Then there is the test. After ulipristal, test if your period is more than 7 days late (ulipristal SmPC); after levonorgestrel, test if it is more than 5 days late (Levonelle SmPC). Both SmPCs also say to test if the bleeding is abnormal. The FPAHK's advice is to see a provider if your period is more than a week late (FPAHK).

Severe pain low in the abdomen after either pill needs urgent attention. Both SmPCs say an ectopic pregnancy should be considered if pregnancy occurs, so this is not a symptom to sit with (Levonelle SmPC; ulipristal SmPC).

Does emergency contraception protect against infections?

No. Neither the pills nor the copper IUD protect against HIV or other sexually transmitted infections (FPAHK). If you are worried that the same encounter left you with an infection, the FPAHK says to ask a healthcare provider about further tests.

Which emergency contraception does PockDose list?

PockDose lists Plan B (Levonorgestrel), generic Plan B: levonorgestrel 1.5 mg, one tablet a dose, in packs of 8, 12, 18, 24 or 30 tablets. No prescription is needed to order it. Because the tablet works best the sooner it is taken, WHO notes that an advance supply can be kept at home so it is on hand to take as soon as possible after unprotected sex (WHO).

The same hormone appears in everyday contraceptive pills, taken daily rather than once. Levlen (Levonorgestrel + Ethinylestradiol) contains levonorgestrel 0.15 mg with ethinylestradiol 0.03 mg; Alesse (Levonorgestrel + Ethinylestradiol) is a combined daily pill with the same two hormones; and Ovral (Norgestrel + Ethinylestradiol) uses norgestrel instead. These are for regular contraception, not for emergencies.

You can browse the levonorgestrel range, read more on the emergency contraception page, or look through women's health for related options.