Women's health
Combined hormonal contraception
The combined pill, patch and ring — Oestrogen-plus-progestogen contraception — highly effective, with specific eligibility checks.
Education and reference only. This is a plain-language class overview — it deliberately contains no doses. Always check the current Summary of Product Characteristics (SmPC), the BNF and your local formulary before prescribing or administering any medicine.
What it is
Combined hormonal contraception contains an oestrogen and a progestogen and is available as a daily pill, a weekly patch or a monthly ring. It is very effective when used correctly and has non-contraceptive benefits too.
How it works
The hormones mainly prevent ovulation, with additional effects on the cervical mucus and womb lining, so that pregnancy is very unlikely while the method is used correctly.
In practice
In practice the most important step is the eligibility assessment before prescribing: the small but real risk of blood clots means combined methods are avoided in people with certain conditions (such as migraine with aura, a personal history of clots, or higher cardiovascular risk), guided by the UK Medical Eligibility Criteria. Check blood pressure and risk factors, counsel on what to do after missed doses, and remember the protection covers pregnancy only, not sexually transmitted infections.
Examples
Practical use
How to take it & use it well
- Use your method consistently as directed, whether that is a daily pill, a weekly patch or a monthly ring, at around the same time.
- Follow the missed-dose or late-application rules in your leaflet carefully, as protection can be reduced if a pill is missed or a patch or ring is left off too long.
- If you have vomiting or severe diarrhoea, treat it like a missed pill and check the leaflet, as the hormones may not be absorbed.
- Have your blood pressure and overall suitability reviewed regularly with your GP or contraception clinic.
- Seek urgent advice if you develop a painful swollen leg, chest pain, breathlessness or a sudden severe headache.
Common uses
- Contraception
- Menstrual cycle control and heavy/painful periods
- Acne and some other indications
Monitoring
- Blood pressure and risk-factor review before and during use
- Reassess eligibility if health changes
- Migraine pattern (especially new aura)
Weighing it up
Advantages & disadvantages
Advantages
- Used correctly it is a highly effective and reversible way to prevent pregnancy.
- It often makes periods lighter, more regular and less painful.
- It can help with symptoms such as acne and premenstrual mood changes for some people.
- Fertility usually returns quickly once the method is stopped.
Disadvantages
- It carries a small increased risk of blood clots in the legs or lungs.
- It is not suitable for everyone, including some people who smoke, have migraine with aura or have certain medical conditions.
- It can cause side effects such as breast tenderness, mood changes, nausea or breakthrough bleeding.
- It needs to be used consistently, and missed doses or late changes can reduce protection.
Key safety principles
What to watch for
- Small increased risk of venous and arterial clots — assess eligibility (UKMEC) before prescribing.
- Avoid with migraine with aura, history of thromboembolism, and certain cardiovascular risks.
- Effectiveness reduced by missed doses, vomiting and some interacting drugs; no protection against STIs.
Key interactions
What to avoid or check alongside
- Enzyme-inducing drugs such as rifampicin and some epilepsy medicines can lower hormone levels and reduce contraceptive protection.
- The herbal remedy St John's wort can also reduce effectiveness and risk unplanned pregnancy.
- Lamotrigine levels can be affected by combined hormones, which may change seizure control.
- Some HIV and hepatitis C medicines interact and may need an alternative or additional contraceptive method.
Patient & carer advice
- Know what to do if you miss a dose or are unwell
- Seek urgent help for calf pain/swelling, chest pain or breathlessness, or new migraine with aura
- Use condoms as well to protect against infections
Use with
Related clinical calculators
Dose and risk decisions for this class often depend on renal function, weight or bleeding/stroke risk. These tools help:
Answers
Combined hormonal contraception: frequently asked questions
What should I do if I miss a pill?
It depends on how many you have missed and where you are in the pack. Follow the missed-pill instructions in your leaflet, and use condoms and consider emergency contraception if advised.
Who should avoid combined hormonal contraception?
It is generally avoided in people with migraine with aura, a history of blood clots, certain heart or liver conditions, and in some smokers, especially over a certain age. Your clinician will assess your suitability.
Does combined contraception cause blood clots?
It slightly raises the risk of clots in the legs or lungs. The overall risk stays low for most people, but warning signs like a painful swollen leg or chest pain need urgent care.
Why does migraine with aura matter?
Migraine with aura combined with these hormones increases stroke risk, so a progestogen-only or non-hormonal method is usually recommended instead.
Will my fertility return after stopping?
Yes. Fertility normally returns quickly after stopping, often within the first cycle or two, so use another method straight away if you do not want to conceive.
Authoritative sources
Always verify against the source
This overview is for orientation. For doses, interactions, contra-indications and the full monograph, use:
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