How the non-hormonal coil (IUD) works
This coil does not release any hormones, so the natural hormones of your menstrual cycle will continue.
The non-hormonal coil works locally, just in the womb (uterus) by creating a very mild inflammatory reaction. This is enough to stop both sperm and egg from surviving and to prevent eggs from implanting.
When will it stop you getting pregnant?
The non-hormonal coil will start to prevent pregnancy as soon as it’s inserted.
Types of non-hormonal coil
Different types of coil use slightly different methods to keep small amounts of copper in the uterus.
The T-shaped coil
The most common non-hormonal coil is a T-shaped plastic frame wrapped with copper wire:
the T-shaped frame is designed to fit within the triangular shape of the womb (the arms of the T fold down so they can pass through the neck of the womb)
the size of the device shows how much copper is on it and how long it will last, but it will be between 5 and 10 years depending on the design. For a 10-year coil, the copper is on the arms and the stem of the T-shape. With the 5-year coil the copper is often only on the stem of the T
The frameless coil
A new style of IUD is a ‘frameless device’, which consists of copper beads on a soft wire. These are also called the intrauterine ball or IUB. These are not currently available in the UK.
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