Patient information · Women's health
Contraception options
what the effectiveness figures actually mean
Every method quotes two numbers: how well it works when used perfectly, and how well it works in real life. For methods that depend on remembering something, the gap between the two is enormous — and that gap, rather than the headline figure, is what should drive the choice.
Seek urgent medical advice if you have
- a calf that is swollen, painful or hot, or sudden breathlessness or chest pain
- a sudden severe headache, weakness, numbness or speech difficulty
- severe abdominal pain after a coil fitting, or with a positive pregnancy test
- fever with pelvic pain and discharge in the weeks after a coil fitting
- migraine with aura for the first time while on a combined method — stop it and contact us
Combined hormonal contraception slightly increases the risk of blood clots, and this is why clot symptoms need acting on. In an emergency call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
The methods, by real-world effectiveness
- Implant — a small rod in the upper arm, 3 years, the most effective reversible method. Irregular bleeding is the main drawback and the main reason for removal.
- Hormonal coil (IUS) — 5 to 8 years depending on type. Usually makes periods much lighter or stops them, which is why it doubles as treatment for heavy periods.
- Copper coil (IUD) — 5 to 10 years, entirely hormone-free. Periods often become heavier and more painful, particularly at first.
- Injection — every 12 to 13 weeks. Often stops periods. Can delay return of fertility by up to a year after stopping, and affects bone density with long-term use.
- Combined pill, patch or ring — regulate cycles, reduce period pain and acne. Not suitable with migraine with aura, high blood pressure, high BMI with other risks, smoking over 35, or a history of clots.
- Progestogen-only pill — suitable for most people including while breastfeeding and where combined methods are not. Unpredictable bleeding is common.
- Condoms — the only method also protecting against sexually transmitted infections, and worth using alongside another method.
Long-acting methods work better because they remove the human factor
The pill is over 99% effective taken perfectly and about 91% effective in reality — roughly 9 in 100 users pregnant within a year. That is not carelessness; it is what happens to any daily task over 365 days. Methods you cannot forget close the gap entirely, which is why they are recommended first for anyone who wants reliability.
Choosing
Worth considering
- Do you want periods lighter, regular, or absent?
- Would you rather not think about it daily?
- Do you want fertility back quickly afterwards?
- Do you need STI protection as well?
- Do you want to avoid hormones entirely?
Things that rule methods out
- Migraine with aura — no combined methods
- Smoking over the age of 35 — no combined methods
- Previous blood clot, or some clotting conditions
- Certain epilepsy and HIV medicines, which reduce effectiveness
- Breast cancer, current or past — discuss individually
Practical points
- Irregular bleeding is common in the first three to six months with progestogen methods and usually settles. Judging a method at six weeks is judging it too early.
- There is no need for a break from hormonal contraception, and no evidence it causes long-term weight gain other than with the injection.
- Fertility returns quickly after stopping all methods except the injection.
- Vomiting or severe diarrhoea can stop pills working — use condoms for the following week.
- Coil fittings are uncomfortable for most and painful for some. Pain relief, local anaesthetic and an unhurried appointment make a real difference — ask.
- You can switch methods at any time, and trying one does not commit you to it.
Book an appointment if you want to discuss options, start or change a method, or have a coil or implant fitted or removed. We offer unhurried consultations with same-day fitting, and appointments long enough to talk it through properly.
Contraception advice and fitting arranged
Unhurried women's health appointments seven days a week.
Tower Bridge Hospital London
97–99 Whitechapel Road, London E1 1DT
WhatsApp 07903 284 189
info@mhwclinic.co.uk
Open Mon–Sat, 9am–7pm (closed Sundays until September)
In an emergency
Call 999, or go to the Royal London Hospital Emergency Department, Whitechapel Road, London E1 1FR.
When we are closed and it is not an emergency
Call NHS 111 or visit 111.nhs.uk.