Norethisterone is a progestogen used in several situations: delaying a period, treating heavy or painful periods, managing irregular bleeding, and as a component of some contraceptives and hormone replacement therapy.
An important point that causes real confusion: when norethisterone is prescribed to delay a period or treat bleeding, it does not work as contraception. It is a hormone tablet, but it is not a contraceptive pill, and you are not protected against pregnancy while taking it for those purposes. If you need contraception, arrange it separately.
Common hormonal medicine side effects
- Bloating and fluid retention
- Breast tenderness
- Nausea
- Headache
- Mood changes or irritability
- Breakthrough bleeding or spotting while taking it
- Tiredness, acne, and changes in sexual desire
For a short course these are usually mild and stop once the course finishes.
Bleeding, mood, skin, weight and cycle changes
When used to delay a period, bleeding normally begins a few days after the last tablet, though this varies. Spotting while taking it does not necessarily mean it is not working, and the cycle afterwards may be different from usual before settling back.
See period delay pill side effects, bleeding afterwards and a missed period after norethisterone.
Low mood or irritability is reported and usually resolves after the course. Over a longer course, acne and fluid-related weight change can occur.
Serious warning signs that need medical attention
Get emergency help for:
- Pain, swelling or redness in one calf or thigh
- Sudden breathlessness or chest pain
- Sudden severe headache, one-sided weakness, difficulty speaking, or loss of vision
- Yellowing of the eyes or skin
See hormonal medicine and blood clot symptoms. Also contact a doctor for very heavy bleeding, severe abdominal pain, or severe low mood.
Who may be at higher risk?
Tell your doctor or pharmacist about a personal or family history of blood clots, liver conditions, migraine with aura, a history of breast cancer, current or possible pregnancy, or unexplained vaginal bleeding that has not been investigated. Norethisterone is not appropriate in pregnancy.
Repeated or prolonged use for period delay is worth reviewing rather than treating as routine.
What to discuss with your doctor, pharmacist or clinic
- When exactly should I start and stop it for the dates I need?
- Do I need contraception as well while taking this?
- Is it safe for me given my history?
- When should my period arrive afterwards?
- If my periods are heavy enough to need this regularly, what else should we look at?
Related contraception, HRT and hormonal medicine guides
- Hormonal contraception side effects
- Hormonal medicine side effects
- Women’s health and hormonal medicine side effects
- When to see a doctor about hormonal medicine
- Report a hormonal medicine side effect
See also Primolut N and heavy period medicine side effects.
Medical Disclaimer: This content is for informational and educational purposes only and does not constitute medical diagnosis, prescription, or professional advice. Always read the patient information leaflet and consult a qualified doctor or pharmacist regarding any medicine or health concern.