What is it?
An extract of the peel of the lemon, Citrus limon. Citrus peel extracts are made by soaking the peel in water, alcohol or glycols, and can contain flavonoids such as hesperidin, sugars and, depending on the process, some of the peel’s aromatic oil. Lemon peel extract is used mostly in shampoos, conditioners and cleansers, and also in skin care, where it is listed as a skin-conditioning and skin-protecting ingredient.
Key information
- The CIR Expert Panel concluded in 2016 that citrus peel ingredients, including lemon peel extract, are safe when formulated to be non-sensitizing and non-irritating.
- Leave-on products must contain no more than 15 ppm of bergapten (5-MOP), a natural citrus compound that can cause skin reactions in sunlight.
- Lemon peel extract was reported in 150 products in 2016, at up to 0.14 percent in leave-on products.
- A moisturizer with 0.1 percent lemon peel extract caused no irritation in a 14-day human test.
More information
Suppliers described to the Cosmetic Ingredient Review (CIR) citrus peel extracts made by soaking fresh or dried peel in water with ethanol or butylene glycol, then filtering, and containing flavonoids, sugars and hesperidin. In 2016 data, lemon peel extract was the most used of the 47 citrus peel ingredients the CIR reviewed, in 150 products, more than half of them rinse-off hair and cleansing products. Reported concentrations were low: up to 0.14 percent in leave-on and 0.057 percent in rinse-off products.
The CIR Expert Panel found a consistent lack of irritation and sensitization across the citrus peel data and concluded that these ingredients are safe when formulated to be non-sensitizing and non-irritating, provided leave-on products contain no more than 15 ppm (0.0015 percent) of bergapten (5-MOP), a furocoumarin that can cause phototoxic reactions in sunlight. A moisturizer containing 0.1 percent lemon peel extract caused no irritation in a 14-day human cumulative irritation test and was not predicted to irritate eyes. The Panel named limonene, citral and furocoumarins as constituents that formulators combining several botanicals should keep in check.
Fresh lemon is a different exposure. The CIR’s companion review of citrus fruit ingredients describes many cases of sun-triggered skin reactions after contact with lemon and lime juice, and in a Danish study of professional food handlers, 15 of 191 patients had positive skin prick tests to lemon peel. On labels, look for Citrus Limon Peel Extract. Lemon peel oil is a separate ingredient, and new EU rules require it to be named on labels above 0.001 percent in leave-on and 0.01 percent in rinse-off products.
Sources: CIR: Safety Assessment of Citrus Peel-Derived Ingredients as Used in Cosmetics (final report, 2016); CIR: Safety Assessment of Citrus Fruit-Derived Ingredients as Used in Cosmetics (final report, 2016); EUR-Lex: Commission Regulation (EU) 2023/1545 on labelling of fragrance allergens
