Safety: Can be used undiluted, however it's best to do a patch test first. Limit usage to the problem area, and avoid the surrounding skin. Tea tree may cause irritate skin for sensitive skin types. Do not massage directly on or below varicose veins.
Disclaimer: Please note, the International Federation of Aromatherapists do not recommend that Essential Oils, Carrier Oils, or Hydrosols be taken internally unless under the supervision of a Medical Doctor who is also qualified in clinical Aromatherapy.