Acid percentage and pH are both important measures, but they tell you different things about a product’s acidity. Acid percentage refers to the concentration of acid in a solution, while pH measures how acidic or alkaline that solution is on a scale from 0 to 14.
Understanding acid percentage
Acid percentage is the amount of acid in a product, expressed as a percentage of the total formula. For example, a product with 10% glycolic acid contains 10% of that specific acid. This tells you the strength of the acid but not how it will behave on your skin.
Understanding pH
pH measures the acidity or alkalinity of a solution on a scale from 0 (highly acidic) to 14 (highly alkaline), with 7 being neutral. The pH of a product affects how it interacts with your skin. For example, a low pH (acidic) product can exfoliate, while a high pH (alkaline) product can disrupt your skin’s natural barrier.
Why both matter
A product’s effectiveness depends on both its acid percentage and pH. A high acid percentage with a high pH may be less effective than a lower acid percentage with a low pH. Always check both numbers to understand how a product will work.
Practical takeaway
When choosing skincare products, look for both the acid percentage and pH level. This will help you understand the product’s strength and how it will interact with your skin. For example, a product with 5% glycolic acid and a pH of 3.5 is likely to be effective for exfoliation without being too harsh.