FSIHS Leading Research Project on Essential Oils as Endocrine Disruptors

The FSIHS Research Department is investigating the proposed link between lavender and tea tree oils and endocrine disrupting outcomes such as prepubertal gynecomastia in children. 

Through a partnership with the National Association for Holistic Aromatherapy (NAHA), the Franklin School of Integrative Health Sciences’ Research Department is leading a 3-part research project to investigate the proposed link between lavender and tea tree essential oils and endocrine disrupting outcomes, including prepubertal gynecomastia.

With support from NAHA and some of the industry’s leading personal care product and essential oil companies, FSIHS researchers have developed a measurement instrument that can successfully measure childhood exposure to these essential oils through personal care products. This instrument will be used to conduct epidemiological studies on the outcomes associated with these exposures.

While multiple laboratory studies over the last decade have uncovered potential endocrine disrupting effects of essential oils, this proposed link has yet to be either substantiated or rejected through epidemiological studies. Without an analysis of the effects of these ingredients within the human body, the safety of these two oils in pediatric products cannot be confirmed scientifically. These studies will be the first to identify the outcomes of the use of lavender and tea tree essential oils in personal care products for babies and children.

“This research is long overdue,” said Dr. Jessie Hawkins, the lead researcher for this project. “For over ten years, the question of whether or not lavender and tea tree essential oils are safe for routine application to children has created debate and controversy. We’re excited to finally produce some evidence that either establishes safety or identifies the prevalence of this outcome. This work will not only improve pediatric essential oil safety guidelines but also produce some of the first epidemiological research evaluating the outcomes associated with long-term exposure to essential oil-based products.”

The 2-year research project began November 2018 and is expected to be completed late 2020. Researchers at FSIHS are employing multiple methodologies to evaluate the potential connection in a comprehensive manner. The project begins with a cross sectional study which evaluates multiple endocrine-related outcomes and numerous routes of exposure. It also includes a case-control study to specifically identify the potential for a link between these two oils and prepubertal gynecomastia. “Between the two studies, we have several thousand children participating from across the country. This ensures that our team can evaluate the potential link comprehensively–if a relationship exists, we’re going to find it,” says Hawkins.

“The data we collect from this project will be groundbreaking for the essential oil industry and the field of aromatherapy,” said Christy Hires, Assistant Researcher and Aromatherapy Department Chair at the FSIHS. “The safety–or possible lack thereof–of these two oils within pediatric formulations is one of the most significant questions we hear from our students. While aromatherapists and leaders of the natural products industry believe these oils to be safe, there is currently no scientific evidence to support that opinion. The goal of this research is to resolve the discrepancy between practice and evidence.”

The project will allow FSIHS researchers to identify whether or not a relationship between lavender and tea tree essential oils and prepubertal gynecomastia exists. It will also allow FSIHS researchers to evaluate the potential for relationships between these two essential oils and multiple other endocrine disrupting outcomes, including precocious puberty in young girls and endocrine-related cancers. Upon completion, the research team plans to use these findings to establish improved safety guidelines for essential oils in pediatric populations.

Funding for this project comes from the FSIHS Research Department, and contributions from NAHA and industry leaders in both the personal care products industry and the essential oil industry. A crowd funding project led by NAHA is also planned for Spring 2019, and corporate sponsorship opportunities are still available. All corporate and industry sponsors must agree to abide by the FSIHS research ethics guidelines which prevent conflicts of interest in the research itself. For more details, contact the FSIHS Research Department at info@franklininstituteofwellness.com


The Franklin School of Integrative Health Sciences is a research-focused natural health college that educates and trains future aromatherapists, health coaches, and herbalists. The college’s nonprofit research department, the Franklin Health Research Foundation, conducts original clinical studies on the actions of herbal products, essential oils, dietary supplements, and preventive health behaviors for both academic purposes and industry sponsors. This unique approach to research and education enables graduates of the Franklin School of Integrative Health Sciences to become world leaders in the field of evidence-based integrative health.