Progestogen (POP / IUS / emergency contraception)

Levonorgestrel

Brand names: Mirena, Levosert, Jaydess, Kyleena, Levonelle

Adult dose

Dose: Emergency contraception: 1.5mg PO single dose within 72h (up to 96h reduced efficacy); IUS: insertion per device (Mirena 8 years, Levosert 6 years, Kyleena 5 years, Jaydess 3 years for contraception)

Route: Oral / Intrauterine

Frequency: Single dose (EC) or device-dependent

Clinical pearls

FSRH Emergency Contraception: ulipristal acetate or copper IUD preferred over levonorgestrel for >72h or recent BMI >70kg
Mirena IUS also licensed for HRT progestogen component, menorrhagia, endometrial protection
FSRH guidance for IUS technique and quick-start

Contraindications

Pregnancy (already established)
Active genital infection (IUS)
Distorted uterine cavity (IUS)
Severe liver disease
Hypersensitivity

Side effects

Bleeding pattern changes
Headache
Breast tenderness
Acne
Ovarian cysts (functional)
IUS: expulsion, perforation (rare), PID (rare, increased first 21 days post-insertion)

Interactions

Enzyme inducers (rifampicin, carbamazepine, phenytoin) — reduce EC efficacy → use 3mg dose or copper IUD
Antiretrovirals

Monitoring

IUS thread check at 6 weeks
Bleeding pattern
Pregnancy test if missed period after EC

Reference: BNF; FSRH Emergency Contraception; FSRH Intrauterine Contraception; UKMEC; https://bnf.nice.org.uk/drugs/levonorgestrel/. Verify against your local formulary and the latest BNF before prescribing.

Curated clinical cross-links plus same-class fallbacks.

Calculators

Pathways