Reducing blackheads isn’t always simple, as they involve multiple factors: excess sebum, increased keratinization, and oxidation of the pore’s contents. Among the active ingredients often cited for eliminating blackheads, glycolic acid is recognized as a benchmark. But has its efficacy been scientifically proven? Let’s explore whether glycolic acid can truly reduce blackheads.
Glycolic acid, an ally against blackheads?
Summary
Published on October 19, 2022, updated on September 8, 2025, by Maylis, Chemical Engineer — 6 min of reading
Themes:
The essential point to remember.
Blackheads, or open comedones, form when excess sebum and an accumulation of dead skin cells block the pores, and this mass oxidizes on contact with air.
Glycolic acid can reduce blackheads thanks to its keratolytic action: it weakens the bonds between corneocytes and facilitates the removal of dead cells, thereby unclogging pores.
Several clinical studies have shown that regular use of glycolic acid, whether it is peels performed in an institute (with sessions spaced two to three weeks apart and concentrations above 15%) or cosmetic care at home (applied daily at lower concentrations, around 2%), reduces the number of open and closed comedones after four to eight weeks of use.
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Blackheads, in brief.
The blackheads, or open comedones, are common retention lesions that mainly affect combination to oily skin. Blackheads develop when excess sebum produced by the sebaceous glands accumulates within skin pores, combined with dead cells and impurities (pollution, product residues, etc.). This buildup forms a plug that enlarges the pores. When exposed to air, the sebum oxidizes on contact with oxygen, producing the characteristic dark color of open comedones.
The blackheads are not merely unsightly: they can worsen. When they rupture, they release their contents onto the skin’s surface, or if manipulated, may become infected and develop into inflammatory lesions, such as the red, painful pimples of acne. That is why it is strongly advised against attempting to extract your own blackheads. It is better to adjust your skincare routine.
How does glycolic acid affect blackheads?
Glycolic acid is an effective ally for oily skin and acne-prone skin.
Derived from the alpha-hydroxy acid (AHA) family, it stands out for its simple chemical structure and low molecular weight (76 Da), making it the smallest AHA and the most able to penetrate the epidermis. The glycolic acid is primarily recognized for its keratolytic action: it works by weakening the bonds that hold corneocytes together within the stratum corneum, facilitating their removal. By gradually releasing these cellular plugs, glycolic acid helps to unclog pores and restore better sebum flow, thereby helping to prevent and remove blackheads.
The interest in glycolic acid in reducing blackheads and tightening pores has been demonstrated across various studies. One such investigation assessed the efficacy of a series of glycolic acid peels combined with 15% glycolic acid home treatments in 40 acne patients presenting with both open and closed comedones. Participants underwent four peel sessions at either 35% or 50%, depending on acne severity, spaced three weeks apart. Encouraging results were observed in comedone reduction. At the end of the eleventh week, 32.5% of participants displayed a marked reduction in their comedones and 57.5% showed significant improvement. However, it is regrettable that blackheads (open comedones) were not distinguished from whiteheads (closed comedones), which somewhat limits the interpretation.
Effects of glycolic acid on comedones.
Source: CHAN H.-L. & al. The effect of glycolic acid on the treatment of acne in Asian skin. Dermatologic Surgery (1997).
Another study explored the interest of AHAs, particularly glycolic acid, within an innovative protocol combining chemical peeling and a physical suction effect. In this work, 23 women had their faces divided into two zones: one treated solely with an AHA-based peel (2% glycolic acid and 2% lactic acid), and the other treated with the same peel combined with mechanical aspiration. The researchers measured pore dilation and the number of comedones before the intervention and then at one, two, and four weeks thereafter.
The results indicate that in the group combining peeling with a physical action, blackheads and whiteheads decreased significantly from the first week, and this improvement was maintained for up to four weeks. In the group receiving the peeling alone, a reduction trend was also observed, albeit to a lesser extent. The authors conclude that combining a gentle AHA peel with a physical action enhances efficacy against comedones, including blackheads, although using a peel alone remains effective as well.
Note: Even though the effect of glycolic acid combined with physical aspiration appears to be more effective, it is accompanied by greater risks. Indeed, the combination of the chemical action of AHAs, which temporarily weakens the skin barrier, and mechanical stimulation can increase skin sensitivity and cause redness. This type of protocol must therefore be carried out with caution, ideally under professional supervision, and is not suitable for sensitive skin or prone to irritation.
Effects of glycolic acid on blackheads (control group = chemical peel alone; test group = chemical peel plus mechanical suction).
Source: SHIN M. K. & al. The effect of physically applied alpha hydroxyl acids on the skin pore and comedone. International Journal of Cosmetic and Dermatology (2015).
Sources
CHAN H.-L. & al. The effect of glycolic acid on the treatment of acne in Asian skin. Dermatologic Surgery (1997).
KAWASHIMA M. & al. Glycolic acid chemical peeling improves inflammatory acne eruptions through its inhibitory and bactericidal effects on Propionibacterium acnes. The Journal of Dermatology (2011).
SHIN M. K. & al. The effect of physically applied alpha hydroxyl acids on the skin pore and comedone. International Journal of Cosmetic and Dermatology (2015).
MURUGAIAH C. & al. Efficacy and safety of superficial chemical peeling in treatment of active acne vulgaris. Anais Brasileiros de Dermatologia (2017).
