What Is Lemon Juice?
The question ‘what is lemon juice?’ may seem like it has an obvious answer but in the context of skincare and skin health, it is actually a little complicated. Lemon juice for skin has recently increased in popularity with a number of DIY blogs recommending its use. These blogs and articles claim that lemon juice is good for acne, strengthening nails, helping dandruff, pigmentation and even soothing chapped lips (ouch!).
These claims seem to come from the fact that lemon juice contains a number of ingredients that are frequently used in skincare such as vitamin c, vitamin B3, and citric acid. However, it is important to remember that the ingredients in a formulation or product do not make it beneficial to the skin. One of the most important parts of formulating with key ingredients is making sure the formulation is safe and non-irritating to the skin. For this reason, and some other reasons, lemon juice is not an ingredient you should be using on your skin.
Lemon Juice For Skin
the good: Contains vitamin c, vitamin B3, and citric acid. However, these are often in low concentrations and you are better off sourcing these ingredients through other products.
the not so good: Lemon juice can be irritating, can damage the skin’s natural barrier, can cause nasty burns when exposed to sunlight, and can dehydrate the skin.
Who is it for? All skin types except those that have an identified allergy to it.
Synergetic ingredients: Works well with most ingredients.
Keep an eye on: NDefinitely consider avoiding this ingredient unless it is formulated properly.
What Are The Claimed Benefits of Lemon Juice?
Lemon juice is claimed to help acne, strengthen nails, help dandruff, pigmentation, and even soothe chapped lips. These claims are not supported by any substantial scientific research and maybe an extrapolation of the benefits of the vitamin C, vitamin B3, and citric acid that lemon juice contains. Just because lemon juice contains these ingredients doesn’t mean it provides the same benefits. The benefits of these ingredients will depend on concentration, source, formulation, and sensitivity.
Why Should You Avoid Lemon Juice?
Concentration and source
While lemon juice does contain vitamin C, vitamin B3, and citric acid the concentration of these ingredients is quite low when compared to formulated skincare products that contain these key ingredients. Given that lemon juice is sourced from naturally-occurring fruit, the concentrations of these ingredients will vary greatly based on the variety of lemon, where it is grown, and under what conditions it is grown. This will also apply to the acidity of the lemon as well. It’s hard to know what you’re using.
For example, ascorbic acid which is the chemical name of the naturally-occurring vitamin C is usually formulated between 5-15%, niacinamide or vitamin B3 usually between 2-10% and acids, like citric acid, such as AHAs 2-10%. While lemon juice usually contains less than 0.05% ascorbic acid, 5% of citric acid, and less than 0.0001% of niacin, which is a precursor to niacinamide or vitamin B3.
One of the other issues with using lemon juice is that as it is a naturally-occurring ingredient it has not been formulated to be stable. This means that the key ingredients, in particular, ascorbic acid are prone to degradation when they are exposed to light and air. This may negate any potential benefit to the skin, leaving behind an acidic juice that irritates the skin.
Let’s talk about pH. pH is the measure of how acidic or basic something is. The skin’s natural pH sits in the range of 4.7-5.75. Lemon juice is highly acidic with a pH of 2. This means that the skin’s natural pH is disrupted and brought into the acidic range. The pH of a product is an important part of the formulating process as it ensures the product isn’t irritating or damaging to the skin. The prolonged use of acidic products has been linked to disruption of the skin’s natural barrier, moisture loss or transepidermal water loss, and sensitivity.
One of the other interesting side effects of lemon juice on the skin is that it can cause blistering and burns when worn in the sun. This reaction is called phytophotodermatitis and is caused by some of the natural compounds in the fruit increasing your sensitivity to the sun. This reaction is also common with limes and celery. If your stomach is feeling up to it google image ‘phytophotodermatitis lemon juice’, warning though, it’s not pretty.
So, Is Lemon Juice Safe For The Skin?
The answer is that is probably best to avoid using it on the skin, particularly if you have sensitive, irritated or inflamed skin. There are products with the key ingredients you find in lemon juice that are formulated to be safe and non-irritating.
Klimek-Szczykutowicz M, Szopa A, Ekiert H. Citrus limon (Lemon) Phenomenon-A Review of the Chemistry, Pharmacological Properties, Applications in the Modern Pharmaceutical, Food, and Cosmetics Industries, and Biotechnological Studies. Plants (Basel). 2020;9(1):119.