Chemical Peel Acids (Glycolic, Lactic, Trichloroacetic, Jessner's)

Also known as: glycolic acid (AHA), lactic acid (AHA), trichloroacetic acid (TCA), Modified Jessner's solution

Dermatology

In plain English

These are chemical peels applied in the clinic to exfoliate the skin for acne, dark spots, uneven texture, and photoaging. Glycolic and lactic acids (AHAs) are gentler 'superficial' peels; trichloroacetic acid (TCA) and Jessner's solution can go deeper. They cause controlled peeling so fresher skin replaces the old surface. Strength and depth are chosen by the provider, and sun protection afterward is essential.

The science

Alpha-hydroxy acids (glycolic, lactic) reduce corneocyte cohesion to promote epidermal exfoliation and stimulate collagen; TCA precipitates proteins to produce controlled coagulative necrosis at a depth set by concentration; Jessner's solution (lactic + salicylic + resorcinol/glycolic variants) is a keratolytic combination used alone or to prime for TCA. Comparative acne studies show AHA, salicylic, and TCA peels are effective with good safety profiles when depth is matched to indication and skin type.

References

• Kessler E et al., alpha- vs beta-hydroxy acid peels in facial acne (RCT), Dermatol Surg 2008
• 25% TCA vs 30% salicylic acid peel in mild-moderate acne (comparative study), 2021