Yes it is safe to have most types of coil fitted while you are taking tamoxifen treatment. There are several types of coil or intrauterine contraceptive devices (IUCDs). They all work by stopping a fertilised egg from being implanted in the lining of the womb.

One type of coil, the Mirena coil, contains the female hormone progesterone. Because some breast cancers can be stimulated to grow by progesterone, as well as by oestrogen, it is usually best not to have this type of coil fitted.

The coil releases progesterone directly into the womb (uterus). But, it is possible that very small amounts of the hormone will be carried elsewhere in the body. So, many doctors are cautious about fitting women with hormone sensitive breast cancer with this type of coil.

The World Health Organisation (WHO) recommends that women do not use this type of coil for at least 5 years after being diagnosed with breast cancer. Even if there is no sign of breast disease after five years, use of this type of coil is not recommended but may be considered. If this applies to you, it is important to discuss this issue with your cancer specialist.