When choosing a skincare product let’s face it: many of us are lured by the thought of high percentage ingredients. We scan product offerings like pseudo scientists assuring ourselves that more means more and the higher the percentage the better the result.
When it comes to acids however, the percentage of the acid in a formulation is only one factor to consider and not always indicative of efficacy.
In cosmetic formulation when working with acids there are three deciding factors in how effective or “strong” the product is going to be which work together to determine the product outcome. These are the percentage, the type of acid and the pH of the formulation.
What is pH?
pH tells us how acidic or alkaline a product is. pH is measured on a scale from 1 to 14 with pH 1 being highly acidic and pH 14 highly alkaline. pH 7, the midway point is considered neutral.
How does pH affect the skin?
Skin is naturally slightly acidic with a pH of around 4-6. A balanced pH is considered the first step in maintaining healthy resilient skin and variances too far either end of the pH scale a major contributor to unfavourable skin conditions. A balanced pH is vital when introducing acids into a skin care regime to help minimise potential reactions which can occur as acids penetrate and temporarily manipulate the skins protective barrier.
How does pH affect the efficacy of Acids?
In skincare the pH of an acid will determine the strength and bioavailability (how much of the acid the skin can use) and the acid’s ability to successfully penetrate the stratum corneum and therefore the depth of exfoliation. Low pH acids will have maximum penetrative ability whereas a higher pH results in weaker exfoliation because the acid has been partially neutralised.
