Combined oral contraceptive
Norethisterone with mestranol
Brand names: Norinyl-1
Adult dose
Dose: 1 tab daily for 21 days, 7-day break
Route: PO
Frequency: OD
Clinical pearls
- Older COC; modern lower-dose ethinylestradiol/levonorgestrel formulations preferred
Contraindications
- VTE history
- Migraine with aura
- Smoker >35y
- Hormone-dependent tumour
- Pregnancy
- Severe hepatic disease
Side effects
- VTE
- Breakthrough bleeding
- Mood change
- Breast tenderness
Interactions
- Enzyme inducers (rifampicin, AEDs, St John's wort)
Reference: BNF; FSRH; https://bnf.nice.org.uk/drugs/norethisterone-with-mestranol/. Verify against your local formulary and the latest BNF before prescribing.
Related
Curated clinical cross-links plus same-class fallbacks.
Calculators
Pathways
- Spinal Anaesthesia Hypotension Management · AAGBI; ASA
- Pre-Eclampsia / Eclampsia in ED · NICE NG133; RCOG Green-top 10A
- Suspected Ectopic Pregnancy · NICE NG126; RCOG Green-top 21
- Polycystic Ovary Syndrome (PCOS) · International PCOS Guideline 2023; NICE CKS
- Pre-eclampsia Management · NICE NG133 2019
- Ectopic Pregnancy · NICE CG154 / RCOG GTG 21