Women's health
Long-acting reversible contraception
LARC — implant, coil (IUD/IUS), injection — Highly effective, low-maintenance contraception that lasts months to years and is quickly reversible.
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.
Quick answer
What is Long-acting reversible contraception?
Long-acting reversible contraception (LARC) includes the implant, the hormonal and copper coils, and the contraceptive injection. These methods prevent pregnancy for months to years, do not rely on daily use, and are among the most effective contraception — with fertility returning after they are stopped or removed.
- How it works: Most LARC methods release a progestogen hormone that thickens cervical mucus, thins the womb lining and (for the implant and injection) usually stops the release of an egg.
- In practice: In practice long-acting reversible contraception (LARC) — the implant, the hormonal coil (IUS), the copper coil (IUD) and the contraceptive injection — is the most effective everyday contraception precisely because it does not depend on remembering a daily pill, and the methods are promoted as excellent first-line options.
What it is
Long-acting reversible contraception (LARC) includes the implant, the hormonal and copper coils, and the contraceptive injection. These methods prevent pregnancy for months to years, do not rely on daily use, and are among the most effective contraception — with fertility returning after they are stopped or removed.
How it works
Most LARC methods release a progestogen hormone that thickens cervical mucus, thins the womb lining and (for the implant and injection) usually stops the release of an egg. The copper coil works without hormones: copper makes the womb and tubes hostile to sperm and eggs. Because they work continuously without daily input, they remove the main cause of contraceptive failure — forgetting.
In practice
In practice long-acting reversible contraception (LARC) — the implant, the hormonal coil (IUS), the copper coil (IUD) and the contraceptive injection — is the most effective everyday contraception precisely because it does not depend on remembering a daily pill, and the methods are promoted as excellent first-line options. Each has a distinct profile that guides choice. The implant (a small rod under the skin of the arm) and the hormonal coil last for years and commonly change bleeding patterns — often making periods lighter or absent, though irregular bleeding, especially early on, is the main reason people stop. The copper coil is hormone-free, works immediately, can be used as emergency contraception, but tends to make periods heavier and more painful. The injection is given every few months, can reduce or stop periods, but is associated with a small, reversible reduction in bone density with long use and a slower return of fertility after stopping — unlike the implant and coils, where fertility returns quickly. Practical points include a fitting procedure for the coils and implant (with associated small risks), the importance of checking coil threads, and that LARC does not protect against sexually transmitted infections, so condoms still matter. Choice is shaped by bleeding preferences, medical history and whether oestrogen needs avoiding.
Examples
Practical use
How to take it & use it well
- These methods, known as LARC, include the implant, the hormonal coil, the copper coil and the contraceptive injection, and once in place they work for a long time with nothing to remember each day.
- The implant and coils are put in by a trained nurse or doctor during a short procedure, with the coils fitted through the cervix and the implant slipped under the skin of the upper arm.
- The injection is given by a clinician every so often, so the main thing to remember is to book and attend your repeat appointment on time.
- Expect your bleeding pattern to change, as hormonal methods often make periods lighter or stop them, while the copper coil can make periods heavier and more crampy.
- Remember that none of these methods protect against sexually transmitted infections, so use condoms as well if there is any risk.
- Go back to your clinic if you have problems such as troublesome bleeding, pain, or you think the coil or implant has moved, rather than putting up with it.
Common uses
- Highly effective everyday contraception
- When avoiding a daily routine is preferred
- Managing heavy or painful periods (hormonal coil); emergency contraception (copper coil)
Monitoring
- Bleeding pattern and satisfaction with the method
- Coil threads/position and implant site; blood pressure and bone considerations for the injection
- STI risk and the need for condoms; timing of removal/replacement
Weighing it up
Advantages & disadvantages
Advantages
- They are among the most effective forms of everyday contraception, with nothing to remember day to day.
- Once fitted or given, they work for a long time, from months to years depending on the method.
- Hormonal methods often make periods lighter or stop them, which many women welcome.
- Fertility returns quickly after the implant or coils are removed, so they do not delay future plans.
- There is a range to choose from, including a hormone-free copper option, so most women can find one to suit them.
Disadvantages
- Changes in bleeding are common, and irregular bleeding is the main reason women stop these methods.
- The copper coil can make periods heavier, longer and more painful for some women.
- The implant and coils need a fitting procedure, which some women find uncomfortable.
- The injection can cause a small, reversible drop in bone density with long use and a slower return of fertility.
- None of them protect against sexually transmitted infections, so condoms may still be needed.
Key safety principles
What to watch for
- Bleeding pattern changes are common — often lighter or absent periods with hormonal methods, but irregular bleeding is the main reason people stop; the copper coil tends to make periods heavier.
- The injection is linked to a small, reversible drop in bone density with long use and a slower return of fertility afterwards (fertility returns quickly with the implant and coils).
- Coils and the implant need a fitting procedure (small risks); none protect against sexually transmitted infections — use condoms as well.
Key interactions
What to avoid or check alongside
- Unlike the combined pill, the implant, coils and injection are not made unreliable by most stomach upsets or by antibiotics in the usual way.
- Some medicines that speed up the liver, such as certain epilepsy treatments, can make the implant less reliable, so tell your clinic what you take.
- The hormonal and copper coils and the injection are not affected by these liver-acting medicines in the same way, which can make them a better choice for some women.
- The copper coil can also be used as emergency contraception if fitted soon after unprotected sex, which is a useful extra role.
- None of these methods guard against sexually transmitted infections, so condoms remain important when there is any risk, whatever else you use.
Patient & carer advice
- These are the most effective methods because there is nothing to remember day to day
- Your bleeding pattern may change — often lighter, but sometimes irregular, especially at first
- They do not protect against STIs, so use condoms too; fertility returns after removal (a little slower after the injection)
Answers
Long-acting reversible contraception: frequently asked questions
What counts as long-acting contraception?
Long-acting reversible contraception, or LARC, includes the implant, the hormonal coil, the copper coil and the contraceptive injection. Once fitted or given, they work for a long time with nothing to remember each day, which makes them among the most effective everyday methods. There is a hormone-free copper option too.
Will my periods change?
Very often, yes. Hormonal methods such as the implant and hormonal coil tend to make periods lighter, irregular or stop them altogether, which many women welcome. The copper coil, by contrast, can make periods heavier, longer and more crampy. Irregular bleeding is the main reason women stop, so talk to your clinic if it troubles you.
How quickly does my fertility return afterwards?
After the implant or either coil is removed, fertility returns quickly, so they do not hold up future plans for a baby. The injection is different, as fertility can take longer to return after stopping it. If you are thinking about pregnancy soon, mention this so you can choose the method that suits your timing.
Do these methods protect against STIs?
No. None of the long-acting methods protect against sexually transmitted infections. They only prevent pregnancy. If there is any risk of infection, use condoms as well as your chosen method. Condoms are the way to reduce the risk of STIs alongside the strong pregnancy protection these methods give.
Does the contraceptive injection affect my bones?
With long use, the injection can cause a small drop in bone density, which generally recovers after stopping it, and fertility can also take longer to return. For most women this is not a problem, but your clinic will consider it, especially with very long use, and can discuss whether another method might suit you better.
Authoritative sources
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