Exfoliation, AHA and BHA: differences and use

Beginner · SESH Academy

Distinguish physical exfoliation from acids and choose by purpose and tolerance rather than strength alone.

Find the stratum corneum at the top and cell renewal below. This is thick skin, such as a palm; its clear lucidum layer is absent from facial skin.

Find the stratum corneum at the top and cell renewal below. This is thick skin, such as a palm; its clear lucidum layer is absent from facial skin.

Image source · OpenStax College: J. Gordon Betts, Peter Desaix, Eddie JohnsonCC BY 3.0Compressed display copy; illustration content retained.
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What you will learn

Distinguish physical exfoliation from acids and choose by purpose and tolerance rather than strength alone.

Core ideas before application

Which is an AHA?

Lactic acid. Lactic acid is an alpha hydroxy acid.

Which commonly appears in clogged-pore products?

Salicylic acid. Salicylic acid is used in some acne and clogged-pore products, subject to tolerance.

Compare the acidic, neutral and alkaline parts of the pH scale. A pH value alone does not determine exfoliation strength or skin compatibility.

Compare the acidic, neutral and alkaline parts of the pH scale. A pH value alone does not determine exfoliation strength or skin compatibility.

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Is strong burning the goal of exfoliation?

No; it can indicate irritation. Poor tolerance does not prove effectiveness.

Is percentage alone enough to compare acids?

No; type, pH, formula and use matter. The same percentage can produce different exposure when other factors differ.

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