AHA, BHA, PHA — What Are Hydroxy Acids and Which One Is Right for Your Skin?

Walk through any skincare aisle and you will encounter an alphabet soup of acids — AHA, BHA, PHA, glycolic, lactic, salicylic. If you are not sure what any of them mean or which one your skin actually needs, you are not alone.

Here is a clear, straightforward guide.

AHA — Alpha Hydroxy Acids

AHAs are water-soluble acids that work on the surface of the skin. They dissolve the bonds between dead skin cells, encouraging them to shed more efficiently and revealing the fresher skin beneath.

The most common AHAs are glycolic acid (derived from sugar cane, with the smallest molecule and deepest penetration) and lactic acid (gentler, with larger molecules, better for sensitive skin).

AHAs are excellent for: dull skin, uneven texture, mild hyperpigmentation, and dry skin that benefits from gentle exfoliation.

Emerald Derma product: REVEAL Gentle Daily Hydroxy Acid Cleanser uses AHA to exfoliate, brighten and refine skin texture as part of a daily cleansing routine.

BHA — Beta Hydroxy Acids

BHAs are oil-soluble — which means, unlike AHAs, they can penetrate into pores and work on the congestion inside them. Salicylic acid is the most well-known BHA.

This oil-solubility makes BHAs particularly effective for oily skin, enlarged pores, blackheads, and blemish-prone skin. They exfoliate inside the pore as well as at the surface.

BHAs are excellent for: oily skin, congested pores, blackheads, acne-prone skin, and skin that needs more than surface-level exfoliation.

PHA — Poly Hydroxy Acids

PHAs are the gentlest of the hydroxy acids. They have a larger molecular structure than AHAs, which means they penetrate the skin more slowly and cause significantly less irritation. They also have humectant properties — meaning they attract moisture to the skin as they exfoliate.

PHAs deliver the exfoliating and clarifying benefits of acids without the irritation that AHAs and BHAs can cause, making them suitable for sensitive skin types and for those who find traditional acids too harsh.

Emerald Derma product: CLEAR Poly Hydroxy Acid Degreasing Cleanser uses PHA to control oil, clarify pores, and decongest skin — with the gentleness that makes it suitable for daily use.

Which one is right for you?

• Dull, uneven skin or mild pigmentation → AHA (try REVEAL)

• Oily, congested, blemish-prone skin → BHA or PHA (try CLEAR)

• Sensitive skin that reacts to standard acids → PHA (try CLEAR)

• Normal or combination skin → either AHA or PHA depending on primary concern

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