Radioactive iodine (I131) for benign thyroid conditions

Radioactive iodine is used to treat patients with overactive thyroids, multi-nodular disease, and goitres. This treatment has been in use for over 60 years. The iodine comes in a capsule (similar in size to antibiotics) which is taken with water. 

As the thyroid gland naturally takes up the iodine from the food we eat, once digested, the radioactive iodine is absorbed by the thyroid and destroys some of the thyroid tissue, the aim being to reduce the over-activity or to shrink it in size.

Treatment is given as an outpatient, with a typical visit taking  around 30 minutes, after which you may go home.  You may be asked to stop taking your thyroid medication before your treatment, and to re-start it again afterwards. Radiographers will give you further instructions.

You will need to follow radiation protection advice after treatment, which will vary depending on the dose you are given.  It is also essential that you do not have radio-active iodine treatment if you are pregnant or think there is a chance that you might be ( and age 10-55 years) . Radiographers will discuss both these issues with you ahead  of your visit . Please refer  to the patient information booklet for details of our guidance.

For more information please download our patient information leaflet here.

Read our patient radiation protection precautions for Radioactive iodine (i131) here or here.