Harvard Dermatologist Reveals How Glycolic Acid Can Transform Your Scalp, Hair and Skin

Chemical exfoliation is often associated with facial skincare, but dermatologists say its benefits extend far beyond the face — including the scalp and body. Dr Abigail Waldman, a board-certified dermatologist at Mass General Brigham and associate professor at Harvard Medical School, has shared how she uses glycolic acid as part of a gentle, routine-based approach to improve skin texture and scalp health.

According to Dr Waldman, chemical exfoliants help prevent buildup, smooth uneven texture, and support a healthier scalp environment when used correctly. Her method focuses on technique, timing, and barrier protection, rather than aggressive treatments or quick fixes.

“Exfoliation isn’t about overdoing products,” she explains. “It’s about consistency, control, and protecting the skin barrier.”

Apply to a Dry Scalp for Better Results

For those dealing with scalp buildup or flakiness, Dr Waldman recommends applying glycolic acid to a dry scalp, not wet hair. Applying it before washing allows the exfoliant to reach the scalp directly without being diluted by water.

She advises tilting the head back and dispensing the product in a gentle sweeping motion from front to back, ensuring even coverage without excess dripping. Light massage helps distribute the formula and improves absorption.

Limit Frequency to Avoid Irritation

While chemical exfoliants are effective, overuse can trigger irritation. Dr Waldman suggests starting once every three days and adjusting based on individual tolerance.

Using exfoliants too often may lead to redness, dryness, or increased flaking, especially on sensitive skin. Allowing time between applications helps the scalp and skin maintain a healthy protective barrier.

Technique Matters More Than Quantity

Dr Waldman emphasises that how you apply exfoliants is more important than how much you use. A controlled, sweeping motion helps remove dead skin cells and unclog pores without damaging hair follicles or causing unnecessary friction.

On textured or bumpy skin, applying a thin layer — either directly or with a cotton pad — is usually sufficient.

Always Pair Exfoliation With Moisture

Moisturising immediately after exfoliation is essential. Chemical exfoliants increase cell turnover, which can temporarily expose more sensitive skin layers.

Dr Waldman recommends following exfoliation with a rich, nourishing moisturiser to restore hydration, calm irritation, and protect the skin barrier. This step is particularly important for dry or rough areas.

No Rinsing Required

One common misconception is that chemical exfoliants must be washed off. Dr Waldman clarifies that leave-on exfoliants work best when allowed to stay on the skin, gradually breaking down dead cells over time.

Rinsing too soon can reduce effectiveness and limit long-term results.

Start With Clean Skin

Exfoliation should always be applied to freshly cleansed skin or scalp. Residual oil, dirt, or styling products can block absorption and reduce efficacy.

Dr Waldman recommends using exfoliants before other evening skincare products, ensuring active ingredients penetrate properly.

Adjust Based on Skin Sensitivity

Skin tolerance varies from person to person. Dr Waldman advises starting slowly and watching for signs of irritation such as burning, redness, or peeling.

If these occur, frequency should be reduced. Over time, some skin types may tolerate more regular use, but patience remains key to safe and sustainable results.

The Long-Term Benefits

When used correctly, routine chemical exfoliation can improve texture, tone, and clarity. On the scalp, it helps reduce congestion, flakiness, and buildup. On the face and body, it smooths rough patches and enhances the effectiveness of hydrating and barrier-supporting products.

Dr Waldman’s approach reinforces that effective skincare is not about aggressive treatments, but about consistent routines, gentle techniques, and barrier protection.

Consistency — not overuse — is what delivers lasting results.