Levonorgestrel
Levonorgestrel is a synthetic form of progesterone, classed as a progestogen (sometimes called a progestin). It is used to prevent pregnancy and is taken in tablet form. Products may contain levonorgestrel alone for emergency use or combine it with ethinylestradiol for daily contraception. Its main use is contraception, with separate products for emergency and daily use.
Key points
- Levonorgestrel does not protect against sexually transmitted infections.
- It is not a regular method of contraception when used as an emergency tablet.
- A high body mass index may reduce its efficacy.
What levonorgestrel is and what it is used for
Levonorgestrel is a progestogen used for emergency contraception and as part of daily combined oral contraception. Emergency use is for preventing pregnancy after unprotected sex or contraceptive failure. Daily combined use is a routine contraceptive method. In combined tablets, levonorgestrel is paired with ethinylestradiol; the emergency tablet contains levonorgestrel alone.
How it works
Levonorgestrel mainly prevents or delays ovulation. It also thickens mucus at the cervix, which can hinder sperm movement. Together these effects make it harder for sperm to fertilise an egg. It does not disrupt a pregnancy that is already established. The stated onset is 0–2 hours and the stated duration is 24–72 hours.
Forms and brands
Plan B is a 1.5mg levonorgestrel tablet for emergency contraception; levonorgestrel is its only active ingredient. Levlen is a combined tablet containing 0.03mg ethinylestradiol and 0.15mg levonorgestrel; it is used for contraception. The two products differ in strength and in whether levonorgestrel is combined with another ingredient. Both are supplied as tablets. Pharmacy partners in India ship to Malaysia in discreet packaging.
Safety
Levonorgestrel should not be used by anyone with hypersensitivity to it. Minor effects include nausea, fatigue and headache. Moderate effects can include lower abdominal pain, dizziness and breast tenderness. Ectopic pregnancy is a serious side effect and requires immediate medical attention. St John’s wort and rifampicin can interact with levonorgestrel. There is no age restriction, though counselling is recommended for adolescents.
Pregnancy and breastfeeding
If you are already pregnant, discuss this with a healthcare provider. Levonorgestrel is not intended for regular use during breastfeeding. Confirm suitability with a qualified clinician or pharmacist before use.
Further reading
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