Lavender and Tea Tree Oil May Elevate Estrogen Levels

The New England Journal of Medicine published an article in January 2007 suggesting that the repeated use of lavender and tea tree oil products can cause breast growth in boys. It appears that lavender and tea tree oil mimic the effects of estrogen and inhibit the effects of androgen.

If this occurs in boys, there is reason to believe that these oils can also affect the estrogen levels in women, especially estrogen sensitive women such as those with endometriosis. I used tea tree oil shampoo almost every day for seven years before stopping about one month ago. Shortly after I stopped, my endometrioma (cyst) and a growth in my uterus both decreased in size. I am not sure if there is a connection, but I do know that I have been tested to have higher-than-average estrogen levels in the second phase of my menstrual cycle and I do not want to use any product that has been shown to increase estrogen levels, even if the tests have only be done on boys.

It might be a good idea for women who have endometriosis, especially those who have tested to be estrogen dominant to discontinue the use of products with lavender and tea tree oil. Be aware that many products contain lavender as a fragrance but do not list lavender in the ingredients, instead listing the catch-all of "fragrance".