Lemon extract in skincare is a known skin sensitizer and irritant. Lemon extract can have antibacterial properties but it’s incredibly irritating, as lemon juice has a pH of 2, which is incredibly acidic and its use is linked with damage to your skin’s acid mantle. Why does this matter?
Your acid mantle is basically your skin’s immune system. It’s your skin’s natural defense against bacteria and fungi and it likes to stay around a pH 5.5 to be healthy. Damage to the acid mantle can be accomplished by using skin care products or DIY “all-natural” concoctions with a too high (basic/alkaline) or too low (acidic) pH.
Once that happens, symptoms can include:
Burning or itching when using products that you had no reactions to before
Dehydrated skin (dry but oily)
Burns, scaling, cracking skin
Your skin turns dry/oily when it was oily/dry
If you peruse Pinterest, you’ll come across many DIY “all natural” masks and treatments using lemon to lighten brown spots or bleach your skin. The truth is, lemon extract/juice/peel/oil does way more harm than good. Using lemon juice on your skin, or products containing lemon extract, lemon oil, lemon peel and even other citrus extracts and peel oils (like orange, mandarin, grapefruit, etc.) can cause brown discolorations and red rash looking irritation when you go out into the sun. This is a reaction known as phytophotodermatitis or PPD.
The PPD is due to a volatile fragrance chemical known as limonene, of which lemon juice contains a high amount.(Google “oxidized limonene allergy”.) Limonene is very often at the end of a skincare ingredient list as it is a very common fragrance ingredient.
While ignoring Pinterest DIY recipes is easy, unfortunately many skincare companies still use citrus oils in their products, most especially as fragrance. Some do feature citrus oils prominently and devote entire skincare lines to these ingredients.
Some people find that using these ingredients at night or during the day but use a lot of sunscreen to try to counteract its damaging effects. Unfortunately, that may not be enough and their use is best avoided entirely – especially when there are so many other great alternative ingredients and products.
Matura M, Goossens A, Bordalo O, Garcia-Bravo B, Magnusson K, Wrangsjö K, Karlberg A. Oxidized citrus oil (R-limonene): a frequent skin sensitizer in Europe. J Am Acad Dermatol. 2002;47(5):709-14.