Combined hormonal contraceptives
also: COCP · the pill · combined pill · patch · ring
Overview
Oestrogen + progestogen contraception (pill, patch, vaginal ring). Highly effective with perfect use; eligibility governed by FSRH UKMEC.
Mechanism
Ethinylestradiol + a progestogen suppress the hypothalamic–pituitary axis: negative feedback ↓GnRH → ↓FSH/LH → no LH surge → ovulation inhibited (primary action). Also thickens cervical mucus and thins the endometrium.
Indications
- Contraception
- Menstrual cycle control / menorrhagia
- Acne, PMS, endometriosis symptom control
The agents
21+7 or continuous
Lowest VTE risk progestogen — FSRH first choice.
Higher VTE risk; drospirenone is anti-androgen (acne).
weekly ×3 + 1 free week
3 weeks in, 1 out
Adverse effects
Oestrogen-driven; risk highest in first months and with 3rd/4th-gen progestogens.
Risk amplified by smoking, age, migraine with aura, hypertension.
Especially first 3 months.
Offset by ↓ ovarian & endometrial cancer.
Cautions & contraindications
UKMEC 4 — ischaemic stroke risk. Use a progestogen-only method instead.
UKMEC 4.
UKMEC 4.
UKMEC 4 (VTE + lactation).
UKMEC 4.
Interactions
- Enzyme inducers (rifampicin, carbamazepine, some antiepileptics, St John's wort) → contraceptive failure — use alternative method
- No longer requires extra cover with most antibiotics (only enzyme-inducing ones)
Monitoring & kinetics
BP + BMI before starting and at review,Reassess UKMEC at each visit (age, migraine, smoking)
Oral daily / weekly patch / monthly ring. Stop 4 weeks before major surgery (VTE).
Source: FSRH — UKMEC + CHC · BNF — Combined hormonal contraceptives