Grapefruit, But I adore Grapefruit essential oil, and use it regularly in the diffuser. When I first began Learning about aromatherafy in the '90's, I expected grapefruit essential to smell rather harsh and bitter. I was glad to be so wrong when I enjoyed my first whiff. Instead, Grapefruit oil has a pleasantly sweet. Tangy/tart aroma that blends well with a number of other essential oils.For a lovely aromatic combination, try blending it with frankincense oil. I also love it blending with conifers like fir needle oil.
Do not take any oils internally and do not apply undiluted essential oils, absulotes, C02 or other concentrated essences onto the skin without advanced essential oil knowkledge or consultation from a qualified aromatherapy practitioner.