Description
What Is Norethisterone?
Norethisterone is a synthetic progestogen — a hormone similar to the natural hormone progesterone. Progesterone plays an essential role in regulating the menstrual cycle. During the second half of the cycle, progesterone maintains the lining of the womb (endometrium). When progesterone levels fall, menstruation begins.
Norethisterone works by maintaining hormone levels and preventing the lining of the womb from shedding. As a result, your period is postponed for as long as you continue taking the tablets. Norethisterone 5mg tablets are licensed in the UK for a range of menstrual disorders and are widely used for short-term period postponement.
It is important to understand: Norethisterone is not a contraceptive, does not prevent pregnancy, and does not act as emergency contraception.
How to Take Norethisterone for Period Delay
- Start taking one 5mg tablet three times daily
- Begin three to four days before your period is due
- Continue for the number of days required
- Do not exceed 17 days of continuous treatment
Your period will usually begin two to three days after you stop taking the tablets. If bleeding has already started, Norethisterone will not stop your period. If you miss a dose, take it as soon as you remember. Do not take a double dose.
Who Is Suitable for Norethisterone?
You may be suitable if you are over 18, are not pregnant or breastfeeding, have no significant clotting risk, have no severe liver disease, have no hormone-sensitive cancers, and have no unexplained vaginal bleeding.
Who Should Not Take Norethisterone?
Norethisterone may not be appropriate if you have:
- A history of deep vein thrombosis (DVT)
- A history of pulmonary embolism
- A known clotting disorder
- Severe liver disease
- Hormone-dependent cancer such as certain breast cancers
- Unexplained vaginal bleeding
- Known hypersensitivity to Norethisterone
Caution is also required if you smoke, have a BMI over 35, have migraines with aura, have cardiovascular risk factors, or have diabetes with vascular complications.
Drug Interactions
Norethisterone may interact with certain medicines, including enzyme-inducing anti-epileptics, rifampicin and rifabutin, certain HIV treatments, and herbal remedies such as St John’s Wort. These medicines may reduce effectiveness. You must declare all prescription, over-the-counter, and herbal medicines during consultation.
