TCA (Trichloroacetic Acid)

Potent chemical exfoliant for controlled depth peels and resurfacing.

Also known as: Trichloroacetic acid, TCA, trichloroacetate

What it is

TCA is a non-volatile, halogenated acetic acid that causes controlled protein denaturation and coagulation in the epidermis and dermis. It's a fixed-strength exfoliant—unlike AHAs and BHAs, its depth of penetration depends on concentration (10–50%), application time, and skin prep, not pH.

What it does

TCA precipitates proteins in the stratum corneum and deeper layers, triggering a controlled inflammatory response that promotes collagen remodeling and epidermal renewal. At low concentrations (10–15%), it produces light exfoliation; at 25–35%, medium-depth peeling; and at 40–50%, deep peeling with visible frosting. Results include improved texture, reduced fine lines, diminished hyperpigmentation, and scar revision.

The evidence

Strong clinical evidence supports TCA peeling for photoaging, melasma, acne scars, and post-inflammatory hyperpigmentation. Depth of effect is well-documented and reproducible; outcomes depend heavily on operator skill and patient selection. Long track record in dermatology and aesthetic medicine.

Best for

Moderate to severe photoaging, hyperpigmentation, acne scarring, and texture irregularities; best on Fitzpatrick I–III skin (higher risk of post-inflammatory hyperpigmentation in darker skin).

Pairs well with

Retinoids (post-peel recovery), vitamin C (brightening), hydrating serums and ceramides (barrier repair), sunscreen (essential post-treatment).

Use cautiously with

Other strong exfoliants (retinoids, vitamin A) in the same week; avoid in active infection, eczema, or recent isotretinoin use; use cautiously with hydroquinone (risk of irritation).

Cautions

Requires professional application; risk of scarring, dyspigmentation, and systemic toxicity if misapplied or over-neutralized. Contraindicated in pregnancy. Causes significant downtime (5–14 days depending on depth). Strict sun protection mandatory. Not suitable for home use.