Glycolic Acid: Understanding AHAs and Why This One Works

Glycolic Acid: Understanding AHAs and Why This One Works

Written by Founder, Amir Karam MD

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Glycolic acid is also one of the most well-studied AHAs, with research showing measurable improvements in clarity, signs of aging, and skin tone.

As a facial plastic surgeon, I’ve spent more than two decades helping people improve the health and appearance of their skin. One pattern I’ve seen repeatedly is this: the most effective ingredients are often the most misunderstood. 

Glycolic acid is a perfect example. It’s powerful, well-studied, and capable of delivering visible improvements when used correctly. Yet it’s also one of the ingredients most likely to cause frustration when it’s used without a plan.

This article is meant to change that. My goal is to help you understand what glycolic acid actually is, how it works within the category of alpha hydroxy acids, and why a controlled, routine-level approach is what leads to real, lasting skin refinement.

What Is Glycolic Acid and Why Is It So Effective?

Glycolic acid is an alpha-hydroxy acid, commonly referred to as an AHA. It works primarily on the surface of the skin, where many visible skin concerns begin. Research consistently shows improvements in clarity, visible signs of aging, and overall skin tone with regular use, often within weeks rather than months.

At a biological level, glycolic acid helps older surface cells shed more evenly. It loosens the bonds that hold dead skin cells in place so they don’t accumulate and create roughness, dullness, or uneven texture. When this process becomes orderly, the skin looks smoother, brighter, and more refined.

What Is an AHA?

Alpha hydroxy acids are water-soluble exfoliating acids that work on the outer layers of the skin. Their primary role is to support healthy skin renewal by improving how evenly surface cells shed.

It’s important to distinguish AHAs from another category of exfoliating acids, BHAs:

  • AHAs (like glycolic acid and lactic acid) focus on texture, brightness, and tone. They're helpful for dull skin, roughness, and uneven skin texture that sits on the surface.
  • BHAs (like salicylic acid) are oil soluble and move into pores. They are better suited for excess oil, congestion, blackheads, and clogged pores.

This distinction matters because not all exfoliation targets the same concern. If your skin looks tired, uneven, or lacks clarity rather than oily or congested, an AHA is often the more appropriate tool.

Why Glycolic Acid Works Differently Than Other AHAs

Among AHAs, glycolic acid stands out. Glycolic acid is the smallest alpha-hydroxy acid. That small molecular size allows it to interact with the skin very efficiently, which is why it’s known for delivering smoothing and brightening.

That efficiency is also why formulation matters so much.

In poorly designed products or when used too aggressively, glycolic acid can overwhelm the skin barrier. But, when used with intention, it becomes a reliable way to guide the skin’s natural renewal process without creating instability.

How well glycolic acid works depends on how it’s formulated and used in your routine.

How Glycolic Acid Is Used in Skincare

Glycolic acid isn’t a one-size-fits-all ingredient. Results depend on how it’s delivered and how well it’s matched to the skin. When it works well, it’s because these four variables are aligned:

When these variables are aligned, glycolic acid becomes a steady signal rather than a stressor.


The Skin Benefits of Glycolic Acid

When glycolic acid is strategically integrated, improvements tend to be cumulative and predictable. These benefits develop as the skin’s natural renewal process becomes more organized and consistent:

01.
Refines skin texture
by helping compacted surface cells release more evenly. This reduces roughness and eliminates the need for mechanical scrubbing, which can irritate skin.

02.
Brightens dull skin
by restoring even light reflection. When surface buildup is reduced, light reflects more cleanly, giving the skin a clearer and more energized appearance.

03.
Supports an even skin tone
by limiting patchiness caused by uneven shedding, product residue, and surface congestion. This helps the complexion look smoother and more uniform.

04.
Helps soften discoloration
, including post-inflammatory unevenness. By encouraging steady cell turnover, pigmented surface cells move through the shedding cycle predictably.

05.
Improves the appearance of fine lines
by reducing roughness that can exaggerate them. Smoother skin reflects light more evenly, which visually softens fine lines and wrinkles.

06.
Reinforces collagen signaling
by supporting biological pathways associated with skin renewal and firmness. Over time, this contributes to improved overall skin quality.

07.
Enhances product performance
by clearing surface debris that interferes with absorption. Serums and moisturizers apply more evenly and penetrate effectively when the skin is refined.

08.
Promotes clearer-looking skin
by reducing outer layer buildup that can make the complexion look congested, even when breakouts aren’t the primary concern.


These changes don’t happen all at once.

They build gradually as the skin’s renewal process becomes more regulated.


Incorporating Glycolic Acid Into Your Skincare Routine With Rinse

Glycolic acid works best when it’s treated as routine level support, not as a once-in-a-while treatment day. That philosophy is built directly into how I use glycolic acid in Rinse Daily Cleanser, the first step of the KaramMD Trifecta.

Cleansing sets the tone for everything that follows. Rinse is designed to remove more than dirt and oil. It clears residual buildup that can dull the complexion and interfere with how products perform, while keeping the skin toned, comfortable and harmonized.

Rinse balances the power of glycolic acid with barrier-supporting ingredients:

  • Apple amino acids cleanse without stripping your skin's oils and naturally balance pH
  • Aloe Vera soothes discomfort and hydrates to calm the skin during daily cleansing
  • Broccoli seed oil provides lightweight lipid support to maintain barrier comfort
  • Willowherb extract for antioxidant protection against daily environmental stress

Rinse creates a stable baseline you can return to daily. When the first step supports the skin instead of destabilizing it, the rest of the routine can do its job more effectively.

Because glycolic acid increases cell turnover, it can increase sun sensitivity by exposing newer surface cells. Daily SPF is essential to protect results and reduce the risk of irritation or uneven pigmentation.

This isn’t about fear. UV exposure remains the leading driver of premature aging and discoloration. Supporting skin renewal while protecting the skin from UV damage is what allows progress to compound rather than reverse.

Glycolic Acid Through a Smarter Lens

Glycolic acid is often framed through a maximum strength mindset, as if progress should feel intense. In reality, most setbacks don’t come from the ingredient itself. They come from breaking the conditions that allow skin to improve steadily.

In my practice, those conditions come down to what I call the three Cs: commitment, consistency, and continuity. When glycolic acid is used through this lens, the goal shifts from intensity to repeatability. You choose a formula your skin can handle, apply it on a schedule you can sustain, and maintain that signal without disruption.

That’s how daily cleansing becomes more than a habit. It becomes the foundation for skin refinement you can actually keep.

If you’re interested in learning how other evidence-based ingredients fit into a well-designed routine, you can explore additional KaramMD Journal ingredient articles on azelaic acidniacinamidearnica flower, and coconut milk powder as complementary guides.

Amir Karam MD

Board Certified Facial Plastic Surgeon
Founder / Creator of KaramMD Skin

Dr. Amir Karam is a world-renowned facial plastic surgeon specializing in facial and skin rejuvenation. With over two decades of experience, he has helped countless patients achieve a naturally youthful, refreshed appearance. As an innovative surgeon, researcher, textbook author, and speaker, he is a leading authority in his field. Beyond performing surgical procedures that restore a youthful facial shape, he emphasizes the importance of skin quality, ensuring a comprehensive approach to facial rejuvenation. As the founder of KaramMD Skin, he is dedicated to making advanced skincare simple, effective, and accessible—helping you look as young as you feel.

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