How Do Period Delay Tablets Work?

There’s an underlying law of the universe which dictates a woman’s period will always arrive just in time to disrupt important plans. For any woman who’s ever had a special trip or event spoiled thanks to the arrival of her period, having a way of skipping it temporarily would be life-changing.

Users of the combined contraceptive pill are able to postpone or skip their period by starting their next packet of birth control instead of taking the break week. For women on different types of contraceptives (or no contraceptive at all), they’ve had no choice but to deal with their period and all its inconveniences – whenever it arrives. But recently, more and more high-street pharmacies have started selling period delay tablets on prescription – which may just be the solution many women have been waiting for.

Delaying your period

For many years, doctors have been able to prescribe a course of hormone tablets to delay a period. But more recently, retail pharmacists in the UK (such as Boots) have started selling the period delay tablet Utovlan via online consultation with a doctor.

These tablets contain an artificial hormone, similar to the body’s progesterone, which helps to delay the end of a natural cycle – ultimately delaying a period. These pills are only designed to be used by women not already taking the combined oral birth control pill.

The timing of periods is controlled by hormonal changes which take place every month. In simple terms, the hormone oestrogen – produced by the ovaries – causes the lining of the womb to thicken in the first two weeks of each month. After the woman has ovulated, progesterone (another hormone) maintains that womb lining for the next two weeks to prepare for the arrival of a fertilised egg. But if pregnancy doesn’t happen, progesterone levels drop steeply – causing the womb to shed its lining and the woman’s period to begin.

Period delay tablets contain norethisterone, an artificial version of progesterone. These work by keeping the progesterone levels in the body artificially higher for longer – ultimately delaying the arrival of a period. But there is a limit to how long the thickened womb lining can be maintained – so usually it’s only possible to delay a period using these tablets for about two weeks after it was due.

Anyone who wants to use a period delay tablet will need to start them about three days before their period is due. They will need to take the tablets three times a day for as long as they want their period to be delayed (up to a maximum of 17 days of tablets). The delayed period will arrive about two or three days after stopping the norethisterone tablets. Of course, each woman is different, so the effectiveness and timing of the delay can vary a little from person to person.

Suggested Reading: Are You PMSing? Stop Saying These 5 Things To Us During Periods

Period delay tablets: Not a contraception

While period delay tablets may temporarily delay your period, it is not a contraceptive method and cannot be used to prevent pregnancy. Women who don’t use contraception or use non-hormonal contraception (such as the copper IUD) will need to continue to taking measures to prevent pregnancy while using period delay tablets if they don’t want to become pregnant.

There’s virtually no evidence about what happens if a woman using progesterone-only contraceptive methods (such as the implant or progesterone-only pill) takes a period delay tablet. It’s likely that it won’t be harmful to combine these on a once-off basis – but it should be discussed first with the doctor who is prescribing them.

Women using combined oral contraception should not use norethisterone to delay periods. If they want to delay their period, they can skip their pill-free break and start the next pack. This is not harmful and does not affect how well the combined pill works as a contraceptive.

Side effects and risks

Like any medication, norethisterone can have some side effects. The most common ones are acne, menstrual spotting (light bleeding), low mood, loss of libido, breast pain or nausea. Not everyone will experience these.

However there are some women who should not use norethisterone to delay a period. These are women who are or could be pregnant, women who have just given birth and women who are breastfeeding. They also aren’t suitable for women with liver tumours, breast cancer and some other uncommon medical conditions.

The way that norethisterone is metabolised in the body may also increase the likelihood of blood clots. So women who have had blood clots before or are at a higher risk of clotting should avoid using period delay tablets. For the same reason, it’s important for any woman who takes period delay tablets to stay hydrated and move around often, especially on long plane flights. Norethisterone can also interact with some prescribed drugs (such as anti-epileptic or anti-TB medication) and the doctor prescribing the period delay tablets will check what other medication is being taken.

Most women will want to delay a period from time to time, and period delay tablets are one way to do this. Because they are not suitable for every woman, and they still need to be prescribed after a consultation with a doctor. But the option to delay a period once in a while, and the convenience of doing this through a high-street pharmacist, gives women control of their menstrual calendar.

Susan Walker, Reader in Contraception, Reproductive and Sexual Health, Anglia Ruskin University published this article first by The Conversation.