What Does AHA Do for Keratosis Pilaris (KP)?

TL;DR: AHAs dissolve the excess keratin plugging hair follicles -- which is exactly what causes keratosis pilaris. Consistent use smooths the bumps over 6-8 weeks.

What It Is

AHA stands for Alpha Hydroxy Acid. The two most used in body care are glycolic acid (smallest molecule, deepest penetration) and lactic acid (gentler, also hydrating). Both dissolve the bonds between dead skin cells, clearing the surface layer. This is called chemical exfoliation.

How It Works on Body Skin

Keratosis pilaris is not an infection. It is not acne. It is a genetic condition where keratin -- a structural protein -- overbuilds inside hair follicles, creating those characteristic rough, bumpy patches on the upper arms, thighs, and buttocks. No amount of scrubbing physically removes this keratin effectively. AHAs dissolve it chemically. Glycolic acid penetrates deepest and works fastest. Lactic acid is better for sensitive or reactive skin and has the added benefit of drawing moisture into the skin as it exfoliates. At 5% concentration in a wash format, AHA is clinically effective for KP -- and the wash format is safer for daily body use than leave-on formulations.

What to Expect

Weeks 1-2: Skin may feel slightly tingly during use. Rough texture begins to feel less pronounced after the first few washes. Weeks 3-6: Bump height reduces noticeably. Redness associated with KP starts to calm. Weeks 6-8: Significant smoothing visible. KP does not fully cure -- consistent use is required to maintain results.

How to Use It Correctly

Apply to damp skin in the shower. Leave on for 60-90 seconds before rinsing -- this contact time matters. Use 4-5 times per week, not daily initially. As skin adapts, daily use is fine. Do not use on broken or actively irritated skin. Follow with a body moisturiser -- AHA exfoliation speeds moisture loss if skin is left bare.

Who Should Use It

Anyone with KP on upper arms, thighs, or buttocks. Also effective for general rough texture, dry skin that flakes, and dull body skin. Avoid on sunburned or eczema-flared skin. AHAs increase photosensitivity -- wear SPF on exposed areas or use in the evening.

The TLC Pick

The Active 5% AHA + 1% BHA Body Cleanser combines glycolic and lactic acid with salicylic acid -- targeting both the surface keratin buildup and any follicular congestion underneath. Purpose-built for KP.