Chemicals that mimic the body’s natural hormone oestrogen are known to affect a woman’s risk of breast cancer. Evidence is mounting that the aluminium-based compound, which often makes up quarter of the volume of some antiperspirant agents, can break through the skin and that once in the body it could mimic oestrogen. A review just published in the Journal of Applied Toxicology calls for further research to evaluate the potential that this could increase the risk of getting breast cancer.