A drug combination that could be taken before sex has been branded a “promising candidate” for an on-demand contraceptive pill.
A research team from Stanford University said the mixture of two medications had worked well in an initial test cohort of nine women to disrupt ovulation at the time of their cycle when the chances of ovulation were highest.
This has led to hopes that a ‘day before’ contraceptive pill could one day be made available – rather than couples relying on the daily pill, barrier protection, or in cases of unprotected sex, the ‘morning after’ or emergency pill.
“Emergency contraception pills work by inhibiting ovulation,” said Dr Erica Cahill, author of the Stanford research.
“These medications do not affect anything about intercourse or sperm. If they are taken near or after ovulation, they are ineffective. The best way to be effective is to take them before ovulation occurs.
“Ideally, an on-demand or pericoital pill would allow people to take a pill to prevent ovulation ahead of intercourse.”
How does the ‘morning after’ pill work?
The ‘morning after’ pill is a progesterone-only hormone pill that works by delaying the release of an egg from an ovary.
In the UK, there are two types of emergency pill – levonorgestrel, known as Levonelle and ulipristal acetate, known as ellaOne.
As the NHS explains, you need to take the emergency pill within three days (Levonelle) or five days (ellaOne) of unprotected sex to be effective.
There’s usually just one pill to take and the sooner you do, the greater your chances of avoiding pregnancy. The morning after pill does not end a pregnancy that has already implanted.
How might the ‘day before’ pill work?
The days just before ovulation are known as the luteal surge, the hormonal increase that triggers ovulation.
It usually starts about 36 hours beforehand. This is the most challenging time to stop the ovulation process as it’s when an egg is most likely to be fertilised.
Women in the Stanford study were given a mixture of ulipristal acetate, which is currently used in the ellaOne morning-after pill, and meloxicam, a type of non-steroidal anti-inflammatory drug.
Ulipristal acetate can stop ovulation but only when it’s taken before the beginning of the luteal surge. Research suggests meloxicam may be able to disrupt ovulation after the luteal surge has started.
This is why the research team combined both drugs to see if they’d be able to work at a women’s peak fertility.
Nine women took the combined drugs around the time of their luteal surge and then underwent ultrasound scans and had their hormone levels monitored.
In six of the women, ovulation was disrupted. Eight met some criteria for incomplete ovulation. On average, their cycles were three days longer than expected.
How promising is this development?
As Dr Becky Mawson at The Lowdown, a contraceptive advice platform, explains to HuffPost UK: “Contraception works on preventing egg and sperm meeting. The idea behind the day-before contraception is delaying the egg release till after the sperm has died off and therefore can’t fertilise.
“Sadly, a ‘day-before’ contraceptive is still very far from being used even in research setting,” she cautions, stressing the small size of the test cohort.
“We can’t comment on effectiveness as it isn’t being used to prevent pregnancy at moment and only in nine women. Trials will be needed of thousands of women using it to prevent pregnancy and look at failures rates.”
However, Mawson believes “any new research in the area is great. The more options available to people the more chance people will use them to prevent unwanted pregnancy if women don’t want to be using a daily pill anymore.”