Obstetrics & Gynaecology/Progestogen-only pill

Progestogen-only pill

also: POP · mini-pill · desogestrel

Overview

Progestogen-only oral contraception — the safe choice when oestrogen is contraindicated (migraine with aura, VTE risk, breastfeeding, smokers ≥35).

Mechanism

Desogestrel POP primarily inhibits ovulation (≈97%) AND thickens cervical mucus. Traditional (levonorgestrel/norethisterone) POPs act mainly by thickening cervical mucus + endometrial thinning, with less consistent ovulation suppression.

Indications

Contraception when oestrogen contraindicated
Breastfeeding contraception

The agents

Desogestrel (Cerazette/Cerelle)ovulation-inhibiting

12-hour missed-pill window

Preferred — wider window.

Levonorgestrel / Norethisteronetraditional

3-hour window only

Stricter timing.

Adverse effects

Irregular / unpredictable bleedingclassic

Commonest reason for discontinuation; counsel up front.

Breast tenderness, acne, mood changecommon

Functional ovarian cystscommon

No increase in VTE riskcommon

Unlike combined methods.

Cautions & contraindications

Current breast cancerall

UKMEC 4 (hormone-sensitive).

Severe / active liver diseaseall

Interactions

Enzyme inducers reduce efficacy (as CHC)

Monitoring & kinetics

Bleeding pattern review,No BP/VTE monitoring required

Oral daily, no pill-free interval.

Source: FSRH — POP · BNF — Progestogen-only contraceptives