The origin of the rumor
In 2017, the French magazine 60 Million Consumers warned its readers against the use of this essential oil and that of the tea tree ( Melaleuca alternifolia) – both regularly used in personal hygiene products, in detergents and aromatherapy devices, although they are rarely found in combination in the same product. They were accused of being able to cause hormonal imbalances by acting as endocrine disruptors.
Some rare studies
The post made a lot of noise, but it wasn’t the first to raise the issue. As early as 2007, a study published in the New England Journal of Medicine concluded that prepubertal gynecomastia (abnormal breast development) in three boys aged 4, 7 and 10, coincided with the use of products based on essential oils and that the symptoms of the disease disappeared when these products were no longer used. By studying cell lines, the researchers concluded that both lavender and tea tree essential oils had estrogen-boosting and anti-androgenic effects.
Another study , which also looked at just three cases of prepubertal gynecomastia in boys, suggested in 2016 that lavender and tea tree essential oils could – under circumstances yet to be determined – mimic the action. hormones and therefore act as endocrine disruptors.
The suspected link between gynecomastia and regular exposure to lavender or tea tree oil is reinforced by an in vitro study, i.e., involving only cells, presented at the 2018 annual meeting of the American Society of Endocrinology. The study was published the following year. Its authors, researchers at the National Institute for Environmental Health Sciences, United States, tested the impact of eight essential oils on human cancer cells. Their conclusion: the chemicals in these oils disrupt the normal activity of hormones. According to them, some of the chemicals could mimic estrogen and block testosterone, causing hormonal imbalance.
These few studies, however, were carried out on a small scale, and are far from establishing a direct link between essential oil and endocrine disruption. A literature review published in 2020 did not find any evidence associating tea tree essential oil with endocrine disruption in children, and little or no evidence to support a link between the essential oil. lavender and endocrine disruption in children.
There is insufficient data to establish a link. The studies were carried out on essential oils, and not on the lavender itself, in addition to having covered too few cases.