What are period delay tablets? A pharmacist’s guide

A holiday, a wedding, an exam, a religious commitment - sometimes your menstrual cycle collides with life at the worst possible moment. The good news: for most women, a short course of prescription medication can safely delay a period.

In this guide, our pharmacy team explains what period delay tablets are, how they work, when to take them, and what to expect once you stop taking them.

What are period delay tablets?

Period delay tablets are a short-term, prescription-only treatment used to postpone menstruation. In the UK, norethisterone is the only medicine licensed for this purpose [1]. It is a synthetic form of progesterone, one of the hormones that controls your menstrual cycle [2].

If you are wondering what period delay tablets are called at the pharmacy, you will usually see them sold as generic norethisterone 5mg tablets or under the brand name Utovlan [2, 3].

Which period delay tablets are best?

The honest answer is that both contain exactly the same active ingredient at the same strength, so they work in the same way - the main differences are price and packaging [2, 3].

So, in answer to what tablets delay your period: norethisterone is the licensed option, supplied on prescription by a GP or through a registered online pharmacy [1, 4], like Pharmacy Online.

How do period delay tablets work?

Towards the end of each menstrual cycle, your level of natural progesterone falls. That drop is the signal for the lining of your womb to shed - which you experience as a period [2, 5].

Norethisterone works by mimicking progesterone: taking it keeps your progestogen level topped up, so the womb lining stays in place and bleeding is postponed until you stop the tablets [1, 2].

What do period delay tablets do?

In short, period delay tablets hold your hormone levels steady. What happens when you take period delay tablets is that your period is paused for as long as you keep taking them; once you finish the course, your natural cycle takes over again, usually within three days [1].

Do period delay tablets work for everyone?

For most women with regular cycles, yes. But how effective period delay tablets are varies from person to person - NHS medicines guidance notes that both effectiveness and the speed at which bleeding returns afterwards differ between individuals [1].

How long do period delay tablets take to work?

Norethisterone needs a head start: it must be in your system before your natural hormone levels drop, which is why timing matters so much. To delay your period, you usually start taking the tablets three days before your period is due, giving the medicine time to build up and keep progesterone levels artificially high - the signal your body relies on to hold the womb lining in place.

Because of this, norethisterone is not a last-minute fix. If you start once bleeding has begun, the hormonal drop is already underway and the tablets will not reliably hold it back, so plan ahead of your holiday or event.

Taken correctly - one 5mg tablet three times a day - your period stays away for as long as you continue the course, up to a maximum of around 17 days. When you want your period to return, you simply stop; bleeding normally restarts within three days as your hormone levels fall.

Norethisterone does not work as a contraceptive, so keep using your usual contraception if you need to avoid pregnancy. It is intended for occasional use only - if you delay your periods often, speak to your pharmacist or GP.

When to take period delay tablets

Timing is the single most important part of using this treatment successfully. You start taking norethisterone three days before your period is due and keep taking it for as long as you want to hold your period off -— up to a maximum of around 17 days [1, 2].

The tablets work by keeping your progesterone levels artificially high, which stops the womb lining from shedding. That's why they have to be in your system before your natural levels fall.

How many days before your period should you start?

Three days before your period is due is the key point to remember. If you're not sure when that is, count back three days from the date you expect to bleed and start then [1]. Leave it any later - or wait until bleeding has already started - and the treatment is unlikely to work, because the hormonal drop that triggers your period will already be underway.

If your cycle is irregular and you can't confidently predict your next period, speak to a pharmacist or your GP before starting, as the timing is harder to judge and getting it wrong means the tablets may not hold your period back.

How long can you take period delay tablets for?

You typically start norethisterone three days before your period is due and keep taking it while you want to hold your period off, so a full course usually runs to around three weeks in total, delaying bleeding by up to about 17 days.

NHS guidance notes it can be taken for up to three to four weeks if necessary [1]. Your prescriber will confirm the right course length for your circumstances.

How often can you take period delay tablets?

They are intended for occasional, short-term use - a holiday, an event, an exam - not as a routine way to manage your cycle [1]. If you find yourself wanting to avoid periods regularly, or your periods are heavy or painful, talk to your GP: longer-term options such as certain contraceptives may suit you better [1, 5].

How to take period delay tablets

The licensed dose is one 5mg tablet, three times a day [1, 2]. If you are wondering how many period delay tablets you should take, stick exactly to what you have been prescribed - taking extra tablets will not make the treatment work better.

Swallow each tablet whole with water and space the three doses evenly - for example, morning, mid-afternoon and bedtime. Taking them at consistent times keeps your hormone levels stable, which is exactly what prevents bleeding.

If you are still unsure how to use period delay tablets, the patient information leaflet inside the pack explains everything, and your pharmacist can talk you through it [3].

How long after stopping period delay tablets will your period start?

Your period usually arrives within three days of taking the last tablet [1, 2]. How long do period delay tablets last? The delay only continues while you are taking them - the effect wears off quickly once you stop. If your period has not arrived within a few days of finishing the course, take a pregnancy test before considering any further tablets [2].

Is it safe to take period delay tablets?

For most healthy women who have regular periods, norethisterone is a safe short-term treatment when it has been prescribed after a proper medical assessment [1, 2].

Norethisterone is not suitable if you [2, 3]:

• are pregnant, might be pregnant, or are breastfeeding
• have ever had a blood clot (deep vein thrombosis or pulmonary embolism)
• have had a heart attack or angina
• have - or have ever had - breast cancer
• have liver problems, including liver tumours
• had jaundice or severe itching during a previous pregnancy
• have unexplained vaginal bleeding that has not been investigated

The body converts part of each norethisterone dose into a small amount of oestrogen (ethinylestradiol) [2]. Oestrogen slightly increases the risk of blood clots, which is why your prescriber will ask about your weight, smoking status and any personal or family history of clots before supplying this medicine [6]. Women at higher clot risk may be offered an alternative such as medroxyprogesterone, which is used off-label for period delay [1].

At what age can you take period delay tablets?

Regulated online pharmacy services, including Pharmacy Online, typically supply period delay tablets to adults aged 18 and over. If you are under 18, see your GP, who can assess whether treatment is appropriate for you.

Taking period delay tablets when pregnant

Taking period delay tablets while pregnant is never safe - norethisterone must not be used during pregnancy [2, 3]. If there is any chance you could be pregnant, take a test before starting a course.

Can you take period delay tablets on the pill?

If you already take the combined contraceptive pill, you do not need norethisterone at all. The monthly bleed you get on the combined pill is a withdrawal bleed rather than a true period, and you can postpone it by running two packets together [1]:

• 21-day (monophasic) pills: finish your packet, skip the seven-day break, and start the next packet straight away.
• Everyday (ED) pills: skip the seven inactive “dummy” pills and go straight to the active pills in a new packet.
• Phasic pills: the method differs by brand - ask your pharmacist before trying it.

Be aware that back-to-back use is off-label for some pill brands, and breakthrough bleeding or spotting becomes more likely the longer you run packets together [1]. If you take the progestogen-only pill (mini pill), it cannot reliably delay a period, because it often makes bleeding irregular - speak to your prescriber about alternatives [1].

Period delay tablets are not contraception

Norethisterone does not prevent pregnancy, and it offers no protection against sexually transmitted infections [1, 2]. If you are sexually active while taking it, use another method of contraception, such as condoms.

Can iron tablets delay your period?

No - there is no clinical evidence that iron supplements postpone menstruation. Iron tablets contain no hormones, so they have no mechanism for holding back the womb lining.

If your period arrives late after starting iron tablets, something else is likely to be responsible: stress, weight change, illness, or the underlying anaemia the iron was prescribed for can all disturb your cycle [5]. If your periods have become irregular, mention it to your GP.

The only medicine licensed in the UK to delay a period is norethisterone [1].

What are the side effects of period delay tablets?

Like every medicine, norethisterone can cause side effects, although many women complete a short course without any problems. The most commonly reported effects include [2, 3]:

• nausea or feeling sick
• headaches
• bloating and fluid retention
• breast tenderness
• spotting or light breakthrough bleeding
• low mood or mood changes
• acne or oily skin
• tiredness

Most of these are mild and settle as your body adjusts. Some women also notice familiar premenstrual symptoms - bloating, cramps, irritability - even though they are not bleeding.

Stop taking the tablets and seek medical help straight away if you notice possible signs of a blood clot: pain, swelling or redness in one leg; sudden chest pain; breathlessness; or coughing up blood [3]. The same applies to a first-ever migraine, yellowing of the skin or eyes, or a significant rise in blood pressure [3]. Always read the patient information leaflet before starting treatment.

Where to buy period delay tablets

Can you buy period delay tablets over the counter?

No. Norethisterone is a prescription-only medicine (POM) in the UK, so you cannot pick it up from a supermarket or pharmacy shelf [4] - every legitimate supply route involves a prescriber.

Can you get period delay tablets from Pharmacy Online?

Yes. Period delay tablets are a prescription-only medicine, so you can't buy them off the shelf - but that doesn't mean a GP appointment is your only option. There are two main routes:

Through your GP surgery, though it's worth checking their policy first. Some NHS practices class delaying a period for a holiday or event as a non-urgent, non-clinical request and won't prescribe it on the NHS or may charge a private fee.

Through a registered online pharmacy like Pharmacy Online. You complete a short online health questionnaire covering your medical history and any medicines you take. A prescriber reviews your answers to make sure the treatment is safe and suitable for you, and if it's approved, your tablets are dispensed and delivered discreetly to your door - usually without needing a face-to-face appointment.

Whichever route you choose, the prescriber's check is there for your safety: period delay tablets aren't suitable for everyone, so being honest on the questionnaire or with your GP matters.

How much are period delay tablets?

The cost depends on how many days of delay you need, since that determines how many tablets are prescribed. You will find current prices on our period delay treatment page.

Whichever route you choose, use a UK-registered pharmacy like Pharmacy Online.

Period delay tablets at Pharmacy Online

If you are still unsure whether this treatment is right for you, our experienced pharmacy team is happy to help. Start an online consultation or contact Pharmacy Online, and we will advise whether norethisterone is suitable and arrange discreet delivery to your door.

This article is for general information only and does not replace personalised advice from a pharmacist, GP or other qualified clinician.