Levonorgestrel

Please note: these are basic guidelines, refer to your doctor for a professional medical opinion.

Popular brand names:

[POP] Microval; [intra-uterine device] Mirena; [emergency contraceptives] Escapelle, Norlevo

Popular combinations:

[COC] Biphasil, Logynon ED, Nordette, Nordiol, Triphasil

Drug group:

Female sex hormone and oral contraceptive

Prescription needed?

Yes (most preparations)

What does it do?

Levonorgestrel is used as:

• Contraception - in combination with oestrogen (combined oral contraceptive or COC) or alone (progesterone only pill or POP)
• Postcoital emergency contraception (‘morning after pill’) - high dose levonorgestrel, available over-the-counter
• Hormone replacement therapy (HRT) - in combination with oestrogen, for the short-term treatment of menopausal symptoms

How does it work?

• Levonorgestrel is a synthetic hormone similar to the female sex hormone progesterone
• It thickens the mucous at the neck of the uterus (cervix), making it difficult for sperm to enter the uterus

How should it be used?

• Contraception/HRT: tablets should be taken once daily, at the same time each day
• Emergency contraception: take no later than 72 hours after unprotected intercourse

What is the typical dosage?

Your doctor will recommend a dosage tailored to your need, but typically:

• Progestogen-only contraceptive (POP): 30mcg once daily
• HRT and combined oral contraceptive: dose varies according to preparation used
• Emergency contraceptive: 5mg as a single dose as soon as possible (best within 12 hours)
• Intrauterine device: effective for 5 years, then should be replaced

How quickly will it start to work?

Contraceptive protection may not be fully effective for 14 days

How long will the effects last?

24 hours (contraception), other effects up to 3 months
     

When should I stop using it?

Can be safely stopped as soon as contraception is no longer needed  

Is it safe for prolonged use?

Long-term use is associated with:

• POP: small increase in risk of breast cancer
• COC: increased risk of thrombosis/breast cancer, reduced risk of endometrial/ovarian cancer
• HRT: increased risk of thrombosis/breast cancer, for short-term use around the menopause

Regular blood pressure checks, physical examinations and mammograms are required.

What are the possible side effects?

Levonorgestrel alone can cause menstrual irregularities (spotting between or absence of periods).

The following have also been reported:

• More common: swelling of the ankles/feet, weight gain, nausea/vomiting, breast tenderness
• Less common: lower abdominal pain
• Report to your doctor before taking your next dose if you experience: headaches, depression, severe lower abdominal pain (pregnancy must be excluded)

What other considerations are important?

Dosage may be adjusted by your doctor under certain conditions.

• Certain health problems: personal/family history of breast cancer, liver/kidney problems, heart failure, high blood pressure, blood clots or stroke, diabetes, asthma, epilepsy, porphyria, sickle cell anaemia, abnormal vaginal bleeding, recurrent migraines/severe headaches, history of depression
• Other medicines: levonorgestrel may influence or be influenced by many drugs, discuss with your doctor or pharmacist
• Pregnancy and breast-feeding: Not safe (but not usually used) in pregnancy, unlikely to affect the breastfed baby if used at normal doses
• Children: Not prescribed
• Over 60: Not prescribed
• Driving and hazardous work: No known problems
• Alcohol: No known problems.
• Surgery and general anaesthetics: The drug should be stopped before surgery