What is Bionor 5 used for?: A Detailed Guide to Norethisterone

October 6, 2025 •

5 min read

Norethisterone, the active ingredient in medications like Bionor 5, is a synthetic progestogen first developed in 1951 for menstrual regulation. A single 5mg tablet contains this hormonal compound, so what is Bionor 5 used for and how does it affect the body?

Quick Summary

Bionor 5 is a brand-name medication containing 5mg of the active ingredient norethisterone. It is primarily used to treat various gynecological conditions, including heavy and irregular periods, endometriosis, and premenstrual syndrome.

Key Points

Active Ingredient: Bionor 5 is a brand-name medication containing 5mg of norethisterone, a synthetic progestogen.
Treats Menstrual Disorders: It is primarily prescribed to manage heavy, painful, or irregular menstrual bleeding and severe symptoms of premenstrual syndrome (PMS).
Effective for Endometriosis: The medication is used to treat endometriosis by suppressing the growth of misplaced endometrial tissue.
Not a Reliable Contraceptive: Unlike many birth control pills, Bionor 5 is not intended for contraception and a non-hormonal method should be used if pregnancy prevention is necessary.
Requires Prescription: Bionor 5 should only be taken under the supervision of a doctor, who will determine the appropriate dosage for your specific condition.
Significant Contraindications: It should be avoided by pregnant women, individuals with a history of blood clots, or those with certain liver or breast conditions.
Potential for Side Effects: Common side effects include irregular bleeding, nausea, headaches, and mood swings; serious complications like blood clots are possible but rare.

What Exactly is Bionor 5?

Bionor 5 is a brand-specific name for a medication containing 5mg of norethisterone. Norethisterone is a synthetic version of the naturally occurring female hormone progesterone and is classified as a progestogen. This hormone plays a critical role in the female reproductive system, particularly in regulating the menstrual cycle and maintaining the lining of the uterus. By mimicking the effects of natural progesterone, Bionor 5 can help address hormonal imbalances and their related symptoms.

It is important to note that while the active ingredient is a progestogen, Bionor 5 is distinct from other products bearing similar brand names, such as those associated with the Norwegian biotech firm Bionor Holding AS, which have focused on HIV vaccines. The Bionor 5 product containing norethisterone is typically a tablet used for gynecological treatments.

Key Medical Applications of Bionor 5

Bionor 5's primary applications leverage its ability to regulate hormonal cycles and control uterine bleeding. A healthcare provider might prescribe Bionor 5 for any of the following conditions:

Dysfunctional Uterine Bleeding (DUB): Used to treat heavy, prolonged, or irregular bleeding that is not caused by an underlying organic issue. The treatment helps stabilize the uterine lining and prevent further bleeding.
Endometriosis: This condition involves the growth of endometrial tissue outside the uterus, causing pain and bleeding. Norethisterone helps suppress the growth of this ectopic tissue by converting the endometrium to a more stable, pregnancy-like state.
Premenstrual Syndrome (PMS): Bionor 5 can be prescribed to alleviate severe symptoms of PMS, such as mood swings, bloating, and breast tenderness.
Postponement of Menstruation: It can be used to delay the onset of a menstrual period for special occasions. This involves starting the medication a few days before the expected period.
Amenorrhea (Absence of Periods): In cases where a menstrual cycle has stopped for a long period (not due to pregnancy or menopause), Bionor 5 can be used to induce a withdrawal bleed and re-establish a regular cycle.

How Norethisterone Works in the Body

As a synthetic progestin, norethisterone's mechanism of action is multifaceted:

Suppression of Ovulation: At the pituitary level, it inhibits the pulsatile release of gonadotropin-releasing hormone (GnRH), which in turn blunts the luteinizing hormone (LH) surge that triggers ovulation.
Endometrial Control: Norethisterone causes the uterine lining (endometrium) to undergo secretory transformation. By stabilizing the lining, it reduces the likelihood of irregular or heavy bleeding.
Increased Cervical Mucus Viscosity: It alters the cervical mucus, making it thicker and less permeable to sperm, which also contributes to a contraceptive effect in some formulations and dosages.

Dosage and Administration

The precise dosage and duration of Bionor 5 depend on the specific condition being treated. It is crucial to follow a doctor's prescription exactly. The dosage will be determined by your healthcare provider based on your individual needs and the specific condition being addressed.

Comparison: Bionor 5 vs. Other Hormonal Treatments


Feature	Bionor 5 (Norethisterone 5mg)	Combined Oral Contraceptives (e.g., Norgestimate/Ethinyl Estradiol)	Progestin-Only Pills (e.g., Norethindrone 0.35mg)
Active Ingredients	Norethisterone (Progestin only)	Progestin (Norgestimate) + Estrogen (Ethinyl Estradiol)	Progestin (Norethindrone) only
Primary Uses	Menstrual irregularities, endometriosis, PMS, menstrual postponement	Contraception, menstrual regulation, acne	Contraception, often for women who cannot take estrogen
Contraceptive Efficacy	Not a reliable contraceptive. Requires a separate, non-hormonal birth control method.	Highly effective when used correctly.	Effective when used perfectly, but requires strict timing.
Mechanism	Stabilizes uterine lining, suppresses ovulation at higher doses.	Suppresses ovulation, alters cervical mucus, changes endometrium.	Primarily thickens cervical mucus, may suppress ovulation.
Dosage	Varies widely depending on indication, determined by healthcare provider.	Fixed daily dose taken continuously or cyclically.	Fixed daily dose taken at the same time each day.

Side Effects and Safety Considerations

As with any medication, Bionor 5 can cause side effects. Awareness and discussion with a doctor are crucial.

Common Side Effects

Irregular bleeding or spotting, particularly during the first few months
Nausea and vomiting
Headaches and dizziness
Breast tenderness or enlargement
Weight changes
Mood changes or depression
Acne and hair changes (loss or growth)

Serious Side Effects (Seek immediate medical attention if experienced)

Signs of a blood clot (e.g., sharp chest pain, shortness of breath, sudden severe headache, swelling in a leg)
Vision changes (blurred vision, loss of vision)
Symptoms of liver problems (e.g., yellowing of skin or eyes, upper right abdominal pain, dark urine)
Severe mood changes or symptoms of depression

Who Should Not Take Bionor 5?

Pregnant women or those who suspect pregnancy: Norethisterone is contraindicated during pregnancy as hormonal medicines can affect the fetus.
Individuals with a history of blood clots: A past or current history of conditions like deep vein thrombosis (DVT) or pulmonary embolism (PE) increases the risk.
People with liver disease or liver tumors: Liver function can be affected by hormonal medications.
Those with a history or suspicion of breast cancer: Hormone-sensitive cancers are a contraindication.

Potential Drug Interactions

Norethisterone can interact with other medications, potentially reducing its effectiveness or increasing the risk of side effects. It's essential to inform your doctor about all drugs and supplements you are taking.

Enzyme Inducers: Medications or herbal supplements that induce the enzyme CYP3A4, such as rifampicin, carbamazepine, and St. John's wort, can decrease the concentration of norethisterone in the body, potentially reducing its effectiveness.
Antivirals: Certain HIV protease inhibitors can affect norethisterone levels.
Other Medications: Be cautious with certain antifungals (like itraconazole) and other drugs that affect hormonal levels.

Conclusion

Bionor 5, containing the active ingredient norethisterone, is a powerful and effective hormonal medication used for treating a range of gynecological issues, including heavy and irregular periods, endometriosis, and severe PMS. Its action involves regulating the menstrual cycle and controlling uterine bleeding. While offering significant benefits for many patients, its use is associated with potential side effects and is contraindicated in specific medical conditions, most notably pregnancy and a history of certain cardiovascular events. Always consult a qualified healthcare professional to determine if Bionor 5 is the right treatment for your condition and to understand the specific dosage and safety guidelines. It is not a contraceptive and requires an alternative birth control method if pregnancy prevention is desired.

Outbound link to a reputable source for further reading: Norethindrone: MedlinePlus Drug Information

Frequently Asked Questions

For acute dysfunctional uterine bleeding, Bionor 5 may help stop bleeding. For long-term menstrual regulation, it may take a few cycles to establish a more regular pattern, as determined by a healthcare provider.

Bionor 5 may be prescribed to postpone a period. This is typically done under the guidance of a healthcare professional who will provide instructions on when to start and stop the medication.

No, Bionor 5 is not a reliable contraceptive, and you can still become pregnant while taking it. It is essential to use a separate, non-hormonal barrier method, such as condoms, to prevent pregnancy.

If you miss a dose of Bionor 5, it is important to consult the patient information leaflet or your healthcare provider for guidance on how to proceed.

Common side effects include irregular bleeding, headaches, nausea, breast tenderness, weight changes, and mood fluctuations.

Bionor 5 suppresses the growth of endometrial tissue outside the uterus by creating a hormonal environment similar to pregnancy, which helps reduce pelvic pain and bleeding associated with the condition.

Though rare, serious risks include the formation of blood clots, liver problems, vision changes, and severe depression. It is crucial to be aware of the symptoms and seek medical help if they occur.

Some herbal products, like St. John's wort, can interact with Bionor 5 and reduce its effectiveness. Always inform your doctor about any herbal supplements or over-the-counter medications you are taking.