Glycolic Acid: Understanding AHAs and Why This One Works

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.

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.

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.

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:

• Product format determines how long glycolic acid stays on the skin. Cleansers offer short contact time and are often the gentlest entry point. Leave-on formulas remain on the skin longer and can deliver stronger results, but require careful balance. In-office glycolic acid peels use higher strengths under professional supervision for controlled resurfacing. Short contact formats are often underestimated, yet they are among the most sustainable ways to maintain consistent refinement.
• Concentration and pH work together to determine how active glycolic acid is. The percentage on a label rarely tells the full story. When concentration, pH, and buffering are balanced within a formula, glycolic acid can remain effective without becoming unpredictable or irritating.
• Frequency matters more than intensity. Glycolic acid responds best to repeat exposure over time. The right schedule is one your skin can tolerate without tightness, stinging, or lingering redness. Moving too fast is one of the most common reasons skin becomes reactive.
• Skin barrier condition is the deciding factor. If the barrier is already compromised, tolerance drops quickly. When the barrier is supported and stable, glycolic acid tends to integrate smoothly and comfortably into a routine.
  

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

When glycolic acid is strategically integrated, improvements tend to be cumulative and predictable. That’s because exfoliation is really about managing surface buildup. As dead skin accumulates in the stratum corneum, the complexion becomes dull and uneven.

Clearing that buildup restores brightness.

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.

Glycolic acid comes in many forms, and how it’s delivered matters just as much as the ingredient itself. In practice, most issues with glycolic acid don’t come from the acid, but from using too much, too often, or in formats that overwhelm the skin.

In everyday skincare, glycolic acid is typically used in one of three ways:

• Short-contact formats (cleansers): Brief exposure that supports regular surface renewal and is often the most tolerable option.
  
• Leave-on products (toners, serums, creams): Longer contact time can deliver stronger exfoliation, but requires more careful frequency and barrier support.
  
• Professional peels (in-office): Higher-strength treatments where exposure time and skin response are closely managed under supervision.
  

Aestheticians commonly use glycolic acid in routine facials, applying it as a light chemical exfoliant to refresh the skin without triggering irritation. The goal isn’t intensity. It’s steady refinement that keeps the skin bright and balanced.

Problems tend to arise when glycolic acid is treated as something to layer aggressively or escalate quickly. Using formulas that are too strong, stacking multiple exfoliants, or increasing frequency too fast can lead to dryness, sensitivity, and barrier disruption.

In those cases, the skin often looks worse, not better.

For most people, glycolic acid works best when it’s part of a routine that the skin can tolerate consistently. Whether it’s used on its own or incorporated into an existing regimen depends on the format, the skin’s condition, and how well the barrier is supported. More exfoliation isn’t better. The right amount, used predictably, is what delivers lasting clarity.

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, and protecting the skin is what allows progress to compound rather than reverse.

Exfoliation can also occur in ways other than chemical acids.

In some routines, physical or enzymatic exfoliation can achieve a deeper level of refinement without increasing acid exposure. That’s why many people in our community supplement glycolic acid with Polish, which helps lift compacted surface cells more actively while remaining gentle on the skin. Used thoughtfully, this approach delivers the same net effect, clearer, more luminious skin, without compounding dryness, sensitivity, or barrier disruption.

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.

Trifecta was built around that exact approach, which is why glycolic acid is already included in the system.

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 acid, niacinamide, arnica flower, and coconut milk powder as complementary guides.