What is it?
The oil obtained from macadamia nuts. It is mostly monounsaturated fat, rich in oleic and palmitoleic acids and low in polyunsaturated fat. In cosmetics and personal care products it works as an emollient that softens skin and hair, in body and face lotions, cleansing oils, lip products, makeup and hair care. On labels it may appear as Macadamia Ternifolia Seed Oil or Macadamia Integrifolia Seed Oil, which the CIR regards as the same ingredient.
Key information
- The CIR Expert Panel concluded that macadamia seed oil is safe in the present practices of use and concentration in cosmetics.
- In 2010 use data, Macadamia Ternifolia Seed Oil appeared in 533 cosmetic products, at up to 30 percent.
- Macadamia is a major tree-nut allergen in food, but the FDA exempts highly refined oils from the definition of a major food allergen.
- A body product with 30 percent macadamia oil caused no irritation or allergic reactions in a repeated patch test on 55 people.
More information
The CIR report explains that Macadamia ternifolia is an old name once used for the edible macadamia nut and now describes a wild, inedible species. Oil comes from Macadamia integrifolia, so the two ingredient names describe the same oil. In the data the Panel reviewed, the oil was 50 to 67 percent oleic acid and 12 to 25 percent palmitoleic acid, with only 1.5 to 5 percent linoleic acid.
The Cosmetic Ingredient Review (CIR) Expert Panel included both names in its assessment of 244 plant-derived fatty acid oils and concluded that macadamia seed oil is safe in the present practices of use and concentration. A body and hand product containing 30 percent was not irritating or sensitizing when tested undiluted on 55 people, and a cleansing oil with 0.5 percent was judged not to be a sensitizer in a test on 214 people. The report also describes one woman whose lip inflammation from lipstick was traced to macadamia oil and another lipstick ingredient; it improved when she stopped using lipsticks containing them.
The FDA lists macadamia among the tree nuts that count as major food allergens, but the same guidance exempts highly refined oils from that definition. The CIR Panel noted that people with food allergies rarely react to refined oils, especially oils that have undergone more processing, because the allergy-causing proteins do not carry over into refined oil. If you have a macadamia allergy, you may want to check whether a product uses refined or unrefined oil.
Sources: Cosmetic Ingredient Review: Plant-derived fatty acid oils, final report for Expert Panel review (March 2011); FDA: Questions and answers regarding food allergens, Edition 5 (January 2025)
