What is Norethisterone?
Norethisterone is a synthetic progestogen — a laboratory-made form of the naturally occurring female sex hormone progesterone. It is widely used in gynaecological medicine for a range of indications, most commonly to delay menstruation (periods) for a specific period, such as during a holiday, sporting event, or important occasion.
It is available under brand names including Primolut N and Utovlan in various EU countries and is a prescription-only medicine across the EU. It is not a contraceptive at the doses used for period delay.
How does Norethisterone work?
The menstrual cycle is regulated by the rise and fall of sex hormones — particularly oestrogen and progesterone. In the second half of the menstrual cycle (the luteal phase), progesterone levels rise and then fall sharply if pregnancy has not occurred. This fall in progesterone triggers the shedding of the uterine lining, which is the menstrual bleed.
Norethisterone works by supplying exogenous (external) progestogen, maintaining the hormonal conditions that prevent this shedding. As long as norethisterone is taken, progesterone levels remain elevated and the period is delayed. When the tablets are stopped, progesterone levels fall, and the period typically begins within 2–3 days.
Norethisterone does not affect ovulation or the underlying menstrual cycle in the same way as combined oral contraceptives, and it does not reliably prevent pregnancy.
Who is Norethisterone for?
Norethisterone for period delay is suitable for adult women who wish to postpone their period for a specific, short-term period. Common reasons include:
- Holidays, travel, or extended activities where menstruation would be particularly inconvenient
- Sporting events or performances
- Religious observances
- Medical procedures
Norethisterone is not appropriate for women with:
- A personal or family history of venous thromboembolism (DVT, pulmonary embolism)
- A history of arterial thrombosis (heart attack, stroke)
- Severely impaired liver function or active liver disease
- Known or suspected hormone-sensitive cancers (e.g. breast cancer, certain types of endometrial cancer)
- Undiagnosed vaginal bleeding
- Pregnancy (or suspected pregnancy)
A thorough medical assessment is required before norethisterone can be prescribed. This ensures the treatment is appropriate for the individual and that the risks of venous thromboembolism and other serious effects have been properly evaluated.
Dosage
For period delay, norethisterone is taken as follows:
| Parameter | Guidance |
|---|---|
| Dose | 5 mg three times daily |
| Timing | Start 3 days before expected period |
| Interval | Every 8 hours |
| Maximum continuous duration | Up to 17 days (as agreed with doctor) |
| Onset of period after stopping | Typically 2–3 days |
Norethisterone should not be used more than once in a given menstrual cycle. The period following a course of norethisterone may be heavier or more prolonged than usual.
Side effects
Common side effects
- Breakthrough bleeding or spotting: Light bleeding may occur during the course, particularly if the course extends beyond the expected period date
- Breast tenderness or discomfort
- Nausea
- Headache
- Mood changes, including low mood or depression
- Bloating or fluid retention
- Acne or oily skin
Serious risks
- Venous thromboembolism (VTE): Progestogens — including norethisterone — are associated with an increased risk of blood clots (deep vein thrombosis and pulmonary embolism). Women with additional risk factors (obesity, smoking, immobility, family history) should discuss this risk carefully with their doctor before use.
- Liver effects: Norethisterone should not be used in women with active or severe liver disease.
- Mood disturbance: Significant depressive symptoms have been reported with progestogen-containing medicines; women with a history of depression should be monitored closely.
Norethisterone vs Utrogestan
| Medicine | Active Ingredient | Class | Form | Primary Use |
|---|---|---|---|---|
| Norethisterone | Norethisterone | Synthetic progestogen | Oral tablet | Period delay, gynaecological conditions |
| Utrogestan | Progesterone | Natural (micronised) progesterone | Oral capsule / vaginal | HRT, period delay, luteal support |
Utrogestan contains natural progesterone (micronised progesterone) rather than a synthetic progestogen. Some evidence suggests that natural progesterone may have a different (and possibly more favourable) cardiovascular and mood profile compared to synthetic progestogens. The choice between them is a clinical decision that should be made with a doctor.
How to access Norethisterone online in Europe
Norethisterone is a prescription-only medicine across EU member states. It cannot be dispensed without a valid prescription from a qualified medical professional.
Prescrivia operates as a technology intermediary, connecting patients with independent EU-registered doctors for online health assessments. We do not prescribe medicines, employ doctors, or sell medicines directly. If an independent doctor determines that norethisterone is clinically appropriate based on your individual circumstances, they may issue a prescription, which is then fulfilled by a licensed EU pharmacy partner.
Important: Prescrivia does not guarantee that a prescription will be issued. All clinical decisions are made independently by qualified medical professionals.
Important safety information
Tell your doctor before taking Norethisterone if you:
- Have or have had blood clots, heart attack, or stroke
- Are a smoker (particularly over age 35)
- Are obese or have limited mobility
- Have liver disease or jaundice
- Have a history of depression
- Are pregnant, think you might be pregnant, or are breastfeeding
Contraception note: Norethisterone at period-delay doses is not a reliable contraceptive. If you could be at risk of pregnancy, use additional contraception.
Sources
Medical information on this page is based on the following sources:
- European Medicines Agency (EMA). Norethisterone-containing products — Product information. ema.europa.eu
- World Health Organization (WHO). Medical eligibility criteria for contraceptive use — 5th edition. who.int
- Medicines and Healthcare products Regulatory Agency (MHRA). Norethisterone — UK public assessment report. gov.uk/mhra
This content is reviewed periodically to reflect updated clinical guidance. It is provided for informational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for advice relevant to your individual health circumstances.
Frequently asked questions
- What is Norethisterone used for?
- Norethisterone is a synthetic progestogen (a form of the hormone progesterone) used to delay menstruation. It is also used in other gynaecological conditions including endometriosis, premenstrual syndrome, and as a component of certain hormonal treatments. For period delay, norethisterone is typically taken for a few days before the expected start of a period and continued until the period is desired.
- How does Norethisterone delay a period?
- Norethisterone works by maintaining elevated progestogen levels, which prevents the drop in progesterone that normally triggers the shedding of the uterine lining (the menstrual bleed). When norethisterone is stopped, progesterone levels fall and the period typically begins within 2–3 days.
- When should I start taking Norethisterone to delay my period?
- Norethisterone for period delay should be started 3 days before the expected start of your period. It is taken three times daily (at 8-hour intervals). Your period should then be delayed for as long as you continue taking the tablets, typically up to 17 days, though the duration should be agreed with your doctor.
- Does Norethisterone act as a contraceptive?
- At the doses used for period delay (5 mg three times daily), norethisterone is not reliably contraceptive. If contraception is required, additional or alternative contraceptive methods should be used. Women taking norethisterone at these doses should discuss contraception with their doctor.
- What are the main risks with Norethisterone?
- Norethisterone is associated with an increased risk of venous thromboembolism (blood clots) — a risk shared with many progestogen-containing medicines. It is contraindicated in women with a personal or family history of blood clots, certain liver conditions, undiagnosed vaginal bleeding, or known or suspected hormone-sensitive cancers. A medical assessment is required before it can be prescribed.
Behandlinger
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