Women who use permanent hair dye products to color their hair at home do not experience greater risk of most cancers or greater cancer related mortality. While this should provide general reassurance to users of permanent hair dyes, the researchers say they did find a slight increase in risk of ovarian cancer and some cancers of the breast and skin. Natural hair color was also found to impact on the likelihood of some cancers.

Use of hair dye is very popular, particularly among older age groups keen to cover up signs of grey. For example, it is estimated that it is used by 50-80% of women and 10% of men aged 40 and older in the United States and Europe. The most aggressive hair dyes are the permanent types and these account for approximately 80% of hair dyes used in the US and Europe, and an even greater proportion in Asia.

To gain a better understanding of the risk of cancer from use of personal hair dye, researchers analyzed data on 117,200 women. The women did not have cancer at the start of the study and were followed for 36 years. The results showed no increased risk of most cancers or of cancer death in women who reported having ever used permanent hair dyes compared with those who had never used such dyes.