Lavender oil ‘may have led to boys developing breasts’ - Times Online

Lavender oil ‘may have led to boys developing breasts’ - Times Online: "Lavender oil ‘may have led to boys developing breasts’"

Researchers in the US believe that the oils may have hormone-like properties that lead to gynecomastia — the growth of breasts. When the boys stopped using the oils, the breasts disappeared. Writing in the journal New England Journal of Medicine, the researchers say that the repeated use of such oils may disrupt normal hormonal function.

The researchers, from the US National Institutes of Health and the paediatric department of the University of Colorado School of Medicine, say that the oils “may possess endo-crine-disrupting activity that causes an imbalance in oestrogen and androgen pathway signalling”.

They investigated this by growing breast cancer cells in test tubes and adding diluted extracts of lavender and tea tree oil. These experiments showed that the oils had activity that mimicked the female sex hormone oestrogen.

Essential oil are not recommended for use on children or pregnant women.