levonorgestrel at a glance
Medicine class
Progestogen contraceptive
Licensed roles
Emergency contraception by mouth or ongoing contraception using an intrauterine system
Administration
The emergency formulation is swallowed; the intrauterine system must be fitted and removed by a trained healthcare professional
STI protection
Levonorgestrel contraception does not protect against sexually transmitted infections
What is levonorgestrel used for?
The selected products have two distinct licensed contraceptive roles:
The oral tablet is licensed for emergency contraception after unprotected intercourse or failure of another contraceptive method.
Jaydess is licensed as an intrauterine system for ongoing contraception.
Jaydess is not licensed as post-coital emergency contraception, for treating heavy menstrual bleeding or for providing endometrial protection during oestrogen therapy.
How does levonorgestrel work?
Oral emergency levonorgestrel is thought to work mainly by delaying or preventing ovulation and fertilisation before implantation begins; it does not end an established pregnancy. An intrauterine system acts mainly within the womb by thickening cervical mucus, suppressing growth of the womb lining and impairing sperm movement and function. Ovulation usually continues.
levonorgestrel preparations and strengths
Tablet
Route: Oral
Strengths: 1500 micrograms, 1.5 mg
How to take levonorgestrel
Follow the product instructions and advice from the supplying clinician or pharmacist.
Swallow the oral emergency tablet.
If vomiting occurs soon after taking it, contact a pharmacist or clinician because a replacement tablet may be needed.
Jaydess must be inserted using aseptic technique by a trained healthcare professional.
After insertion, check the threads as instructed. If they cannot be felt, use another contraceptive method and arrange an urgent check.
levonorgestrel side effects
Common or expected effects
- Nausea, headache, dizziness, tiredness, lower-abdominal discomfort, vomiting or diarrhoea after oral emergency use
- Temporary changes to the timing or pattern of the next menstrual bleed and breast tenderness
- With an intrauterine system: spotting, irregular bleeding or absent periods, particularly after insertion
- Headache, pelvic or abdominal pain, acne, ovarian cysts, vaginal inflammation or discharge and breast discomfort
Get urgent medical advice
- Severe allergic reaction, including facial or throat swelling
- Pelvic infection after intrauterine insertion
- Partial or complete expulsion or uterine perforation
- Pregnancy with an intrauterine system, particularly possible ectopic pregnancy
- Severe or persistent depressive symptoms
levonorgestrel in pregnancy
Oral emergency levonorgestrel does not interrupt an established pregnancy and should not be used for that purpose. Pregnancy with Jaydess in place requires prompt specialist assessment because ectopic pregnancy must be excluded. Leaving the system in place increases pregnancy complications; removal also carries risks that must be discussed.
levonorgestrel while breastfeeding
UK Specialist Pharmacy Service advises that breastfeeding does not need to be interrupted after oral levonorgestrel used for emergency contraception. Levonorgestrel intrauterine systems are generally compatible with breastfeeding and are not expected to affect milk supply; specialist advice is appropriate for a premature or unwell infant.
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.
Common questions about levonorgestrel
Answers are fully visible for fast scanning and source review.
Does levonorgestrel end an existing pregnancy?
No. Oral emergency levonorgestrel acts before implantation and does not interrupt an established pregnancy.
Can levonorgestrel be used after unprotected sex?
The oral formulation is licensed for emergency contraception after unprotected sex or contraceptive failure. Jaydess is not an emergency contraceptive.
Sources
These sources were used to prepare and review this medicine page.
Prepared and reviewed by the iatroX editorial team.