levonorgestrel: prescribing and clinical use
Focused clinical detail for use alongside current product information, local policy and patient-specific assessment.
levonorgestrel: clinical details
Prescribing considerations
- Identify the intended formulation and indication: oral emergency contraception and Jaydess are not interchangeable.
- Before oral emergency use, assess possible existing pregnancy, menstrual history, further unprotected intercourse, severe malabsorption, significant liver disease, ectopic-pregnancy risk and enzyme-inducing medicines.
- The selected oral product contains lactose.
- Before Jaydess insertion, exclude pregnancy, assess pelvic infection and STI risk, investigate unexplained bleeding and confirm that uterine anatomy permits correct placement.
- Counsel that neither formulation protects against sexually transmitted infections.
Contraindications and cautions
- Oral product: hypersensitivity to levonorgestrel or an excipient.
- Jaydess: pregnancy; current or recurrent pelvic inflammatory disease; acute cervicitis or vaginitis; recent postpartum endometritis or infected abortion; unresolved cervical intraepithelial neoplasia; uterine or cervical malignancy; progestogen-sensitive tumour; unexplained uterine bleeding; cavity-distorting uterine abnormality; acute liver disease or liver tumour; or hypersensitivity.
Monitoring
- After Jaydess insertion, review placement and threads, then reassess periodically or when clinically indicated.
- Investigate missing threads, new heavy bleeding, pain, pregnancy symptoms or suspected expulsion using examination and imaging where appropriate.
- If pregnancy occurs with Jaydess, establish pregnancy location promptly.
- Review troublesome bleeding, infection symptoms or significant mood changes.
Clinical pharmacology
Levonorgestrel is a synthetic progestogen. Oral emergency use primarily inhibits or delays ovulation before implantation. Jaydess produces high local endometrial exposure, thickens cervical mucus and impairs sperm function while maintaining low systemic exposure relative to its local effect.
Formulation and product differences
- The oral emergency product is a lactose-containing tablet intended for occasional use.
- Jaydess is a sterile, single-use, T-shaped intrauterine system with removal threads and a silver ring for imaging identification.
- Jaydess requires trained insertion and removal and is not established for emergency contraception, heavy menstrual bleeding or endometrial protection during oestrogen therapy.
levonorgestrel preparations and strengths
Tablet
Route: Oral
Strengths: 1500 micrograms, 1.5 mg
levonorgestrel interactions
Interactions depend on the formulation. A pharmacist or prescriber should review all prescription, non-prescription and herbal products.
CYP3A4 enzyme inducers
Medicines including carbamazepine, phenytoin, primidone, barbiturates, rifampicin, rifabutin, some HIV medicines, griseofulvin and St John's wort can lower oral levonorgestrel exposure and reduce emergency contraceptive effectiveness; an alternative method may be advised.
Ciclosporin
Oral levonorgestrel may inhibit ciclosporin metabolism and increase the risk of ciclosporin toxicity.
Medicines affecting liver enzymes
These may alter circulating levonorgestrel from Jaydess, but a major effect on contraceptive efficacy is not expected because its action is mainly local.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.