Prepubertal gynecomastia linked to lavender and tea tree oils.
Level 4 - case-series / case-control
Case series of 3 patients with accompanying in vitro bench research.
PubMed 17267908 · doi:10.1056/NEJMoa064725
What was done
Clinicians investigated three healthy prepubertal boys with normal endogenous steroid concentrations who presented with gynecomastia while using topical products containing lavender and tea tree oils. Patient outcomes were monitored after discontinuing product use, and human cell line studies were conducted to assess estrogenic and antiandrogenic effects of both oils.
What was found
No quantitative clinical values are reported in the abstract. In all three boys, gynecomastia coincided with topical application of lavender and tea tree oil products and resolved shortly after product discontinuation. In vitro studies in human cell lines demonstrated estrogenic and antiandrogenic activities for both oils.
Why it matters
This study highlights common topical essential oils as potential endocrine-disrupting agents capable of inducing reversible breast tissue proliferation in prepubertal males.
Limits
The clinical evidence is limited to a three-patient case series without a control group. Exposure concentrations, product formulations, specific timelines, and quantitative endocrine assays are not provided in the abstract. In vitro cell line responses cannot establish in vivo human pharmacokinetics or clinical causality.
Cited by
- supports Lavender oil and tea tree oil possess endocrine-disrupting and hormone-modulating properties.