Glycolic Acid for Acne: How it Works, Efficacy, Best Products, Side Effects

• Glycolic acid is prized for its exfoliative and moisture-retaining properties
• It can address acne and acne scars, fade dark spots, smooth rough texture and hydrate skin
• This acid is available in multiple formulations including cleansers, creams, gels and peels 

Glycolic acid is an alpha-hydroxy acid (AHA) that has proven exfoliative, regenerative and moisture-retaining qualities. As a result, this acid is found in a wide range of skin care products to treat a number of skin concerns. Glycolic acid for acne is an ideal choice as it can effectively work as both a treatment and preventative.

How Glycolic Acid Treats Acne

Acne vulgaris is the most widespread chronic skin condition in the United States, affecting nearly 50 million people per year. When excess oil, debris and Cutibacterium acnes bacteria accumulate in pores, noninflammatory or comedonal acne can develop, manifesting as blackheads and whiteheads.

If left unchecked, bacteria can accumulate, leading to inflammation and infection. This is termed inflammatory acne which presents as pus-filled pustules, nodules or cysts that are red, swollen and tender to the touch.

Acne is notoriously difficult to treat. As such, a successful outcome typically involves a combined approach to target and control symptoms.

Glycolic acid’s many properties make it one agent that is typically part of an acne treatment regimen. It has been proven to be effective in treating both inflammatory and noninflammatory acne. 

Glycolic acid’s molecular size is the smallest among all AHA compounds, allowing it to easily pass through the skin barrier, and as a keratolytic to dissolve the bonds that hold dead skin cells together. This prompts skin cell turnover to reveal brighter, healthier skin. As an effective exfoliant, it can also clear away excess oils and debris.

These actions help heal acne lesions and soften the look of acne scars. It also promotes a healthier complexion via collagen synthesis; collagen helps strengthen and thicken the skin to improve its appearance.   

Glycolic acid also plays a role in balancing moisture in the skin. Many acne treatments can strip skin of its natural oils, which prompts sebaceous glands to overproduce oils in compensation, leading to further breakouts. The act of exfoliation can also leave skin overly dry and cause a dysfunctional skin barrier, leaving skin vulnerable to external aggressors and worsening acne.

Glycolic acid is a humectant, and as such, can attract and retain moisture to strengthen skin barrier function. And unlike other agents, it has been shown to gently and effectively remove the outer layer of skin without compromising the skin barrier.   

Can it be used on active pimples?

Glycolic acid can be safely used on active pimples, blackheads and whiteheads. With inflammatory lesions it can cause burning to open sores, therefore opt for a low concentration formula and use caution. 

Efficacy of glycolic acid for acne

Glycolic acid has been demonstrated to effectively treat and prevent acne due to its strong exfoliating and moisture-retaining qualities. It clears pores of acne-causing oils and debris, and maintains the health of skin by replenishing moisture. 

Glycolic acid is most effective for clearing comedonal acne but can also help heal inflammatory lesions. It has been demonstrated to inhibit bacterial growth of C. acnes even in over-the-counter (OTC) low-strength products. 

In one study of glycolic acid peels on acne with Asian subjects, significant improvements were seen in both inflammatory and noninflammatory acne symptoms. In addition, skin texture was dramatically rejuvenated, pore size was reduced and skin was brighter.. 

Of note is that Asian skin is understood to be more sensitive than Caucasian skin. In this case study only 6.0% of patients had side effects, attesting to the gentle nature of this agent.

In another study of a 5% glycolic acid-based gel on mild-to-moderate acne, skin lesions were significantly improved after 4 weeks, with brighter skin and reduced redness. 

With consistent use, glycolic acid maintains clear pores which helps other skin care products and acne medications to better absorb, and increases their efficacy.

How long does it take to work?

How long glycolic acid takes to work depends on a number of factors including acne severity, treatment history and the strength of the product used.

Which treatment you choose (OTC topicals versus professional peel) also makes a significant difference in outcome as does frequency. Results also differ from person to person.

With that being said, you can expect to see improvements with OTC products within 4–6 weeks, with consistent use. Professional peels differ in strengths and typically require repeat treatments over the course of 1 to 2 months to see final results.

Of note is that before you begin to see improvements, you will experience what’s called a skin purging process. Skin will appear to worsen due to the active ingredients in glycolic acid which accelerates skin cell turnover, drawing up and releasing debris and oils to the skin’s surface. This is expected and could last  4–6 weeks. 

Glycolic acid vs. salicylic acid

Glycolic and salicylic acid are two agents commonly used in OTC and professional treatments. 

Both excel at exfoliating skin and addressing excess oiliness; both have anti-inflammatory and antibacterial properties to fight acne. 

Salicylic acid is an oil-soluble beta hydroxy acid (BHA) that acts as a chemical exfoliate to effectively clear pores of debris and oils; it is superior to glycolic acid in this respect. This acid can also treat and prevent comedones as it can reduce sebum production to keep pores clear.

Glycolic acid’s lower molecular weight allows for deeper and faster penetration, but it works on the surface of skin to slough off dead skin cells. It can also attract and retain moisture, brighten, firm and smooth skin.

Does it work on acne scars?

Yes, glycolic acid can be an effective solution for treating atrophic (depressed) scars that result from acne due to its ability to boost collagen production.  While results can be had with low-strength peels used long term, superior results are seen with repeated use of high-strength peels. 

Through exfoliation, glycolic acid has also been shown to reduce the appearance of postinflammatory hyperpigmentation (PIH). These are the dark marks left behind once an acne lesion has healed. 

When deciding on a course of action for treatment, care providers typically combine one or more therapies for better results. One recent study demonstrated that microneedling and a series of peels is more effective than monotherapy.  

How long do results last?

As acne is a chronic disease, it can’t be cured, but it can be successfully controlled. This would involve consistent use of glycolic acid skin care products and regularly scheduled appointments for professional peels.

The results of a peel will depend on the intensity and can last anywhere from several weeks to months.

In the case of acne scarring, results are permanent once a series of peels is completed but continued acne flare-ups can result in fresh scar tissue. On-going treatment is therefore required.

Glycolic acid products and treatments for acne

Glycolic acid can be found in low concentration formulas in a number of skin care products to suit your needs and skin type.

Glycolic acid in any topical form, is understood to increase sensitivity to the sun which can cause skin damage. With this in mind, it is best to use any glycolic-acid based products at night and ensure you apply sunscreen of at least SPF 30 during the day. In addition, opt for one skin care product and not several as this can lead to irritation and a dysfunctional skin barrier.

Cleansers

Glycolic acid cleansers can be found in concentrations of about 4%–10% and should be chosen based on skin type and sensitivity. If you have oily acne-prone skin, opt for a water-based product. Low strength glycolic acid cleansers can also be safely used with dry and sensitive skin as it is gentle and has natural hydrating properties.

To allow your skin to adjust, use just once every three days and gradually increase to daily use. Follow the provided instructions as glycolic acid penetrates deeply and provides superior exfoliation; overuse can irritate skin and lead to redness and dryness.

Moisturizers

There are a wide range of moisturizing creams and lightweight gels available that exfoliate skin and replenish moisture. Overall, glycolic acid creams and gels have been shown to produce greater results than cleansers as they are left to absorb into skin. 

Additional hydrating ingredients are usually included in these products to increase skin’s overall hydration such hyaluronic acid and vitamin C for its antioxidant, anti-inflammatory benefits.

Creams typically contain low concentrations of glycolic acid (about 5%–8%), while gels range from 8%–10%. As with cleansers, consider your skin type when making a choice; creams would be ideal for dry or sensitive acne-prone skin; gel for oily skin.

At-home peels

At-home glycolic acid peels are available in store in concentrations as low as 10% or up to 40%. 

They are safe for all skin types, even sensitive, however use with caution to avoid irritation. These peels are also suitable for skin of color, which is prone to hyperpigmentation.

Peels can be safely applied once a week or every 2 weeks. Let your skin be your guide as overexfoliation will dry and irritate skin, and acne can worsen. It’s also important to carefully follow the product’s instructions to avoid burning or damaging your skin. 

While there are high-strength peels available online for home use, this can cause severe anaphylactic reactions and significant damage to skin. At these strengths, they can only be administered safely by a skilled dermatologist. 

Professional peels 

Professional chemical peels can be had in concentrations of 20%–70% for a superficial to medium peel and can be safely used in Fitzpatrick skin types I–IV. Typically, treatments start at lower concentrations and gradually increase in strength to allow the skin to acclimate.

Over a series of treatments, glycolic acid peels have demonstrated a significant improvement in comedonal acne, cystic acne, acne scars and hyperpigmentation. 

One study examining glycolic acid peels found they were effective against inflammatory acne due to its inhibitory effect on C. acnes.

Side effects of Using Glycolic Acid for Acne 

Glycolic acid is considered safe for all skin types when used properly but it can cause some side effects.

The most common side effects of skin care products containing glycolic acid are irritation, redness, dryness and flaking. To avoid this, choose a product with a low concentration and use it intermittently before including it as part of your regular skin care routine.

To counteract the drying effects of exfoliation, apply a hydrating serum followed by an occlusive moisturizer to lock in moisture; this will help keep your skin healthy and comfortable. 

Glycolic acid peels can cause burning, pain, itching, redness and swelling. Skin will begin to slough off over the course of several days with the level of peeling dependent upon the intensity of the peel. This will also affect the time needed for downtime. However, when applied correctly, there should be no pain, only mild discomfort.

Using more than one product containing glycolic acid can irritate and dry skin. As well, using alongside certain acne medications can cause adverse reactions; it is therefore advised to speak to your dermatologist before using glycolic acid. 

Can glycolic acid be used with benzoyl peroxide?

It’s not recommended to use glycolic acid with benzoyl peroxide as doing so can lead to excessive dryness. However, you can use them on alternate days and using both provides greater benefits. Benzoyl peroxide can effectively kill acne-causing bacteria while glycolic acid exfoliates skin and rids pores of debris – which also helps the benzoyl peroxide to penetrate deeper.

Takeaway 

Glycolic acid has been demonstrated to be an effective agent in treating and preventing both noninflammatory and inflammatory acne. It can also reduce the appearance of depressed scars and lighten hyperpigmentation. 

Glycolic acid treats acne by inhibiting bacterial growth. As a keratolytic, it can dissolve the bonds that hold dead skin cells together to reveal a brighter smoother complexion. Its low molecular weight means it can penetrate into the deeper layers of skin to clear pores of acne-causing oils and debris. These actions help heal and prevent lesions from forming and prevent comedone formation.  

Glycolic acid also regulates oil production, attracts and retains moisture and boosts collagen production. 

While glycolic acid is gentle and considered safe for all skin types, it can cause dryness or redness if overused or if skin is sensitive. Start with a low concentration product and use intermittently until your skin becomes accustomed to it.