What is norethisterone?
Norethisterone (brand name Utovlan and generics) is a synthetic progestogen — a version of the hormone progesterone. It is nationally authorised across the EU. While it has several uses (including heavy or irregular periods, endometriosis, and premenstrual symptoms), it is best known in primary care as a short course to delay a period — for example, around a holiday, a wedding, or an exam.
It is a prescription-only medicine for period delay in most EU countries. On Prescrivia, requests start from the norethisterone treatment page.
How norethisterone delays a period
In the natural cycle, the fall in progesterone in the second half of the cycle triggers the shedding of the womb lining (a period). Taking norethisterone keeps the progesterone-like hormone high, holding the womb lining in place. When you stop taking it, the lining sheds and a period starts, usually within 2–3 days.
Norethisterone is not a contraceptive. It does not reliably prevent pregnancy and should not be relied on for contraception.
The regimen described in the product information
According to the summary of product characteristics (SmPC) for norethisterone 5 mg tablets, the regimen described for period delay is one 5 mg tablet three times daily, starting three days before the expected period and continued until it is convenient for the period to resume. According to the same product information, courses are short (up to about 10–14 days), and a period usually starts two to three days after the last tablet.
That is a description of the licensed regimen, not an instruction to you. Whether norethisterone is appropriate at all — and the exact dose, start date, and duration for your situation — is a clinical decision made by a doctor who has reviewed your cycle regularity, medical history, and clot-risk factors. Prescrivia does not provide dosing instructions: if an independent doctor decides treatment is suitable, your specific regimen comes with the prescription, and you should follow it and the patient information leaflet exactly.
Who can use it
Most women with no contraindications can use norethisterone short-term for period delay. A clinician will check:
- Whether the expected period date is reliable (less predictable with irregular cycles)
- Your medical history (see below)
- Whether you might already be pregnant
- Any medicines you take
If you are already taking a hormonal contraceptive (pill, patch, ring, implant, injection), you do not usually need norethisterone — speak to a clinician about running pill packets together or adjusting your contraceptive routine instead.
Common side effects
Short courses are usually well tolerated. Possible side effects:
- Nausea
- Headache
- Breast tenderness
- Bloating
- Mood changes, low mood
- Changes in libido
- Spotting or breakthrough bleeding while taking it
- Skin reactions — rare
After stopping, the next period may be heavier or more crampy than usual because more lining has built up. Cycles usually return to normal within a month.
Less common but important risks
Norethisterone (like other progestogens) can slightly raise the risk of blood clots (DVT, PE). The risk is small but real. The risk is higher in women who:
- Are over 35
- Smoke
- Are significantly overweight
- Have a personal or family history of clots
- Are immobile for long periods (e.g. long-haul flights)
- Have certain medical conditions
For a short course for period delay, the absolute risk is very low for most women, but a clinician will assess before prescribing.
Who should avoid norethisterone
Norethisterone is contraindicated in:
- Current or past blood clots (DVT, PE, stroke)
- Active liver disease
- History of breast cancer or other hormone-sensitive cancer
- Unexplained vaginal bleeding (until investigated)
- Pregnancy (and in those trying to conceive — it is not a contraceptive but should not be used in pregnancy)
- Severe migraines with aura (specialist decision)
- Known allergy to norethisterone
Caution is also needed in women with risk factors for clots, heart disease, kidney disease, epilepsy, diabetes, or depression.
Important considerations
- Not a contraceptive: you can still get pregnant while taking norethisterone. If you are sexually and may become pregnant, use a reliable contraceptive too
- Pregnancy test: if there is any chance you might be pregnant when the period is due, take a test before starting norethisterone
- Other medicines: tell your clinician about all medicines, as norethisterone can interact with some (e.g. certain antiepileptics, rifampicin, St John's Wort)
- Surgery: if you are going to have surgery or be immobile, mention this — norethisterone is usually stopped beforehand
- Long-haul travel: long flights can raise clot risk; mention any planned travel
Alternatives
If you cannot take norethisterone, or if you are already on contraception, alternatives include:
- Running packets of the combined pill together (skip the 7-day break) — only if you already take it and have discussed with a clinician
- Back-to-back use of the contraceptive ring or patch
- A progestogen-only pill adjustment under clinician advice
- Menstrual cups or period-proof underwear for managing a period during an event (if delay is not essential)
How Prescrivia can help
Prescrivia connects you with independent EU-registered doctors who can review your medical history, advise whether norethisterone is suitable for period delay, and — if clinically appropriate — arrange a prescription through a regulated pharmacy. Period delay is a short-term option for specific circumstances; a clinician will help confirm it is the right choice for you. You can start a norethisterone assessment review here.
Sources
- Utovlan 5 mg tablets — Summary of Product Characteristics (SmPC), national authorisation.
This article is for general information only and is not medical advice. Always read the patient information leaflet and speak to a qualified clinician before starting any hormonal treatment.