Tea tree (Melaleuca alternifolia) oil contains primarily terpinen-4-ol, but more than 100 other constituents have been identified, including 1,8-cineole (eucalyptol). Tea tree oil should not be confused with cajeput oil, niauouli oil, kanuka oil, or manuka oil which are obtained from other Melaleuca species. No data exist on the safety and efficacy of tea tree oil in nursing mothers or infants. Topical tea tree oil is generally well tolerated, but should not be taken orally. Tea tree oil is usually used topically for the treatment of infections and has been used for prophylactic treatment of the nipples postpartum.[1] However, tea tree oil has estrogenic and antiandrogenic activity and numerous cases of breast enlargement in boys have been reported.[2-5] The relevance of these findings has been questioned,[6-9] but no further testing has been reported to confirm or refute the findings. Topical application around the breast should be avoided unless it is thoroughly removed before nursing.
Dietary supplements do not require extensive pre-marketing approval from the U.S. Food and Drug Administration. Manufacturers are responsible to ensure safety, but do not need to prove the safety and effectiveness of dietary supplements before they are marketed. Dietary supplements may contain multiple ingredients, and differences are often found between labeled and actual ingredients or their amounts. A manufacturer may contract with an independent organization to verify the quality of a product or its ingredients, but that does not certify the safety or effectiveness of a product. Because of the above issues, clinical testing results on one product may not be applicable to other products. More detailed information