The pH stands for “potential hydrogen” and describes the acid-alkaline ratio of substances. 1 is the most acidic and 14 is the most alkaline. If your pH level is too alkaline or too acidic, skin conditions such as eczema and rosacea result because the acid mantle is disturbed. Our ideal pH level should be about 5.5 - slightly acidic.
Your skin is naturally protected by a thin layer made of ceramides, free fatty acids and lipids called the acid mantle. When the acid mantle is mixed with amino acids and lactic acid from sweat, this creates our skin’s pH level.
Since lemon juice is highly acidic at 2 pH, it can cause permanent damage to your skin. Lemon juice can change the natural pH of your acid mantle, potentially causing hyperpigmentation, irritation, and sensitivity.
On the other spectrum, baking soda has a pH of 9.0, which means it's highly alkaline. When we use products with a high pH, we are disrupting our acid mantle.
Acne-prone skin tends to have a slightly higher skin pH, which contributes to the ideal environment for acne. Without the right level of acidity, excess sebum production and overgrowth of the acne-causing bacteria, P. acnes, becomes more problematic for acne-prone skin.
How do we achieve the ideal pH?
A gentle pH balanced cleanser helps to maintain our skin barrier’s integrity. A cleanser that is pH balanced simply means it has a pH similar to that of skin (4.5-5.5).
Normal soaps and many drugstore cleansers have a high pH (8 to 10) that can irritate your skin and disrupt your acid mantle. The goal is to cleanse your skin without over-stripping it of its natural oils. We recommend CeraVe Foaming Facial Cleanser for a cheap and pH friendly cleanser for your skin.
Skin Surface pH in Acne Vulgaris: Insights from an Observational Study and Review of the Literature. 2017.