The coil (IUD and IUS) and the implant explained

The contraceptive implant

The implant is a small, flexible rod placed just under the skin of the upper arm by a trained clinician, using local anaesthetic. It steadily releases a progestogen hormone that mainly stops the ovaries releasing an egg, and it works for up to three years (it can be removed sooner if you wish). It is over 99% effective. The commonest side effect is a change in bleeding pattern — periods may become lighter, irregular or stop — which is harmless but worth knowing about.

The copper coil (IUD)

The intrauterine device, or copper coil, is a small T-shaped device placed inside the womb by a trained clinician. It contains no hormones; the copper makes the womb an inhospitable environment for sperm and eggs. It works for 5–10 years depending on the type, is over 99% effective, and is also the most effective form of emergency contraception. Some people find periods become heavier or more crampy, especially at first.

The hormonal coil (IUS)

The intrauterine system, or hormonal coil, is a similar T-shaped device that releases a small amount of progestogen directly into the womb. It thickens cervical mucus and thins the womb lining, and often makes periods much lighter or stops them — so it is also used to treat heavy periods. Depending on the type it lasts 3–8 years and is over 99% effective. Irregular bleeding is common in the first few months as the body settles.

Having one fitted, and reversibility

Fitting a coil takes a few minutes in a clinic; it can cause cramping and some people find it uncomfortable, so pain relief options are discussed beforehand. The implant is fitted through a tiny injection-like procedure. All three are fully reversible — fertility returns quickly after removal — which is a key advantage over permanent options. A brief check confirms the method is suitable for you before fitting.