Citric Acid
A fruit acid used mostly in tiny amounts to balance a formula’s pH; at higher strengths it is a mild AHA exfoliant.
citric acid, sodium citrate, citrate
Dull skin · Texture & large pores
What it does
Citric acid is one of the most common ingredients on skincare labels, but usually as a helper rather than a hero: in small amounts it adjusts a formula’s pH. Found in citrus fruits including oranges, lemons and grapefruits, citric acid is an alpha hydroxy acid (AHA), and at higher strengths it can gently exfoliate to reveal glowing skin.
How it works
When used as an exfoliant, it loosens the bonds between dead cells on the skin’s surface so they shed more evenly. It is gentler and less studied than glycolic or lactic acid, and it also binds trace metals, which helps keep formulas stable. Used regularly at exfoliating strengths, it can help smooth texture and brighten the look of dull skin.
MG says
Citric acid is often used in skincare to regulate acidity and, at exfoliating strengths, can help achieve a smoother, more even skin texture. Most cosmetic citric acid is made by fermentation rather than squeezed from fruit, and it has no scent of its own. In Auteur Definitive Enzyme Cleanser it is the only AHA in the formula, working alongside keratin-dissolving enzymes.
Cautions
At exfoliating strengths citric acid can sting or irritate, especially when layered with other acids or retinoids, so avoid it in a complex layered routine where possible. Like other exfoliating AHAs, it can make skin more sensitive to the sun, so use a broad-spectrum sunscreen daily and for a week after use.
