Mandelic Acid

The gentlest alpha hydroxy acid.

Excellent choice for sensitive skin.

Helps firm and fade post-breakout marks

Light sensitive so requires opaque packaging.

May be derived from almonds or synthetic.

What is mandelic acid? Mandelic acid is a type of alpha hydroxy acid (AHA). Although in the correct pH range of 3–4 it’s an effective exfoliant, glycolic acid is considered more effective due to its smaller size. As the smallest AHA, mandelic acid is twice as large as glycolic so penetrates more slowly and evenly into skin. These traits make mandelic acid more tolerable for those with sensitive skin or skin cannot tolerate glycolic acid. It’s even suitable for skin prone to rosacea.

Unlike glycolic acid, mandelic acid is light-sensitive and must be packaged in an opaque container to remain effective. Because of this, mandelic acid is less likely to make skin more sensitive to sunlight, an issue with glycolic acid that means daily sunscreen use becomes even more important.

This acid may be synthetic or derived from almonds (Paula’s Choice uses the synthetic kind). Like other AHAs, mandelic acid is most effective in leave-on products when used in concentrations of 5% or greater.

Is mandelic acid an AHA option that is effective for improving uneven skin tone? Mandelic acid seems to have a slight edge over other AHAs when it comes to fading hyperpigmentation, particularly post-breakout marks, melasma, and dark spots from sun exposure, although exactly why this is unknown. It is well tolerated by all skin tones.

Chemically, mandelic acid is oil-loving and water-loving (hydrophilic), allowing it to offer multi-level benefits which include helping skin look and feel firmer and smoother. Mandelic acid can also be combined with BHA or other AHA ingredients.

A couple studies have shown that mandelic acid and salicylic acid worked well together in a higher-strength peel for use on darker skin tones struggling with discolorations, including post-acne marks. Other research using mandelic acid on its own at a 45% strength have shown impressive efficacy and gentleness compared to similar-strength AHA peels, and such peels are considered safe for sensitive skin.

Last, research has shown peel-strength amounts (30% and up) of mandelic acid can increase sebum (oil) production, which isn’t great for oily skin but would be a benefit for dry skin. For this reason, people struggling with discolorations and dry skin may derive dual benefits from such peels.

See: Alpha Hydroxy Acid