What Happens If You Take Norethisterone on the First Day of Your Period?

In short, if you take norethisterone on the first day of your period, it won’t stop your period. So, it is important to take norethisterone 3 days before your period starts to achieve the desired results.

Here we’ll look at what happens if you take norethisterone on the first day of your period and when you should take it to effectively delay your period.

What happens if I take norethisterone on day 1 of my period?

If you take norethisterone on the first day of your period, it’s unlikely to stop your periods from starting. If your period has already started when you take norethisterone, it will not stop it.

However, it may still influence your hormone levels, so you may have a shorter or lighter period than usual, even though it does not stop it completely.

Norethisterone is a man-made form of progesterone. The main function of progesterone is to prepare the female body for pregnancy. Each month a series of changes take place as part of the menstrual cycle to prepare the body for the release and potential fertilisation of an egg.

The menstrual cycle is split into 2 phases:

• Follicular
• Luteal

The first phase is the follicular phase where a follicle cell develops in the ovary, stimulating the production of oestrogen, and preparing for ovulation. At this point, progesterone levels remain low.

When an egg is released, progesterone levels rise during the second half or luteal phase of the cycle and the follicle that’s left behind transforms into a ball of cells called the corpus luteum. The corpus luteum produces progesterone, signalling to the body to prepare for pregnancy. If pregnancy happens, progesterone levels stay high.

If pregnancy doesn’t occur, progesterone levels fall dramatically, and a new cycle begins, starting with your period.

Source: Trends in Cardiovascular Medicine (2017)

Taking norethisterone a few days before your period will effectively trick your body into thinking it might be pregnant, stopping your womb from shedding, and delaying your period until you stop taking it.

When should you take norethisterone?

Norethisterone is most effective for period delay when it is taken 3 days before your period starts.

How to take norethisterone

To delay your period, the typical norethisterone dosing schedule is 1 tablet 3 times a day.

Ideally, you should take norethisterone 3 days before your period is due to start for them to effectively delay your period. Your period should start within 3 days of finishing the norethisterone tablets.

You can find out more detailed information about norethisterone and how to take it in the patient information leaflet.

Does norethisterone prevent pregnancy?

No, norethisterone only delays your period, it does not stop you from getting pregnant. If your period does not start within 3 days of stopping norethisterone tablets, you may be pregnant, speak to your clinician for advice.

If you want to prevent pregnancy rather than delay your period, you should think about the contraceptive pill instead.

What is norethisterone?

Norethisterone belongs to a group of medicines called progestogens, these medications are similar to the naturally produced female hormone progesterone. Norethisterone is a man-made form of progesterone and is commonly taken to delay your period.

Norethisterone is the generic form of the medication. Branded versions are also available from Prescription Doctor. They are:

• Primolut N 5mg
• Utovlan 5mg

The branded versions contain the same active ingredients in the same doses as the generic forms, but branded versions tend to be more expensive.

How does norethisterone work?

During a normal menstrual cycle, progesterone levels naturally fall during your period, but norethisterone keeps your progesterone levels up. Doing so, stops your womb lining from shedding, delaying your period.

Why might you delay your period?

There are several reasons why you might want to delay your period, such as:

• Occasions: You may choose to delay your period if you have an important occasion coming up, such as a wedding, where you don’t want to risk being on your period or experiencing any of the associated symptoms.
• Holiday: If you have an upcoming holiday, you may prefer to delay your period rather than be on it while you are away. Find out how you can best delay your period for a holiday by reading our blog.
• Painful periods: If you experience painful periods, delaying your period can provide some relief.
• Endometriosis: Sometimes delaying your period can help to manage some of the debilitating symptoms associated with endometriosis.

Norethisterone alternatives for period delay

If norethisterone isn’t right for you, Prescription Doctor can provide an alternative called Provera which contains the active ingredient medroxyprogesterone acetate.

Summary

Noresthisterone is an effective period delay medication, taken by women who want to stop their period happening at a specific time, perhaps for an important life event. 

Norethisterone is most effective for period delay when it is taken 3 days before your period starts. If you take it on the day of your period, it won’t delay your period because it works by keeping your progesterone levels high to stop your womb lining from shedding. 

Authored & Reviewed By

Yasmin Ahmed

BPharm - Clinical Lead

Musarat Yasmin Ahmed currently serves as the clinical lead at Prescription Doctor, bringing with her a wealth of experience.

Published on: 06/08/2024 Reviewed on: 06/08/2024