How does glycolic acid target acne?
Acne, sometimes called “acne vulgaris”, doesn’t only affect teenagers, but also adults, and is caused by excess sebum which leads to the appearance of spots (whiteheads, papules, etc). Glycolic acid is present in many skincare products, and is one of the best tools to target breakouts. Let’s take a closer look at how it works on acne.
The reasons why we get acne.
Acne is an inflammation of the skin, in particular the hair follicles, typically characterized by the appearance of acne lesions on the surface of the skin (comedones, papules and pustules), or beneath the skin (lumps and cysts). It’s most common in teenagers but also affects adults. Acne mainly appears on the areas of the body which have the most sebaceous glands, like the face, upper back, chest, neck, shoulders, etc.
Acne is caused by several different factors. It all starts with either excess sebum production or the thickening of the sebaceous gland’s ducts (through which the hair follicle passes to get to the skin’s surface), which blocks the sebum from flowing freely out of the sebaceous gland. In other cases, acne can be caused by hyperkeratinization (in which dead skin cells don’t properly slough off, so accumulate), which traps sebum in the follicle, leading to spots (blackheads and whiteheads).
An oily environment can lead to abnormal overgrowth of a bacteria, Cutibacterium acnes (formerly known as Propionibacterium acnes), on the surface of the skin or in the follicles. This overgrowth of bacteria, which is normally tolerated by the skin, causes inflammation, which leads to lumps and bumps. Then, the blocked follicle can get infected again by other microorganisms present on the skin, causing pustules or cysts containing pus.
Acne can be caused by many things:
Hormonal fluctuations (during puberty, the few days before your period, during pregnancy or menopause) ;
Genetics (family history) ;
Certain medications (oral contraceptives, certain cortisone medications, certain antibiotics, lithium, certain antidepressants, anti-epilepsy medication, immunosuppressants) ;
Using products that are too heavy for your skin ;
Stress (production of substance P by the nervous system, which can influence sebum production) ;
Repeated rubbing or friction on a particular area of skin.
When healed, acne can leave you with scars (dark marks) that may be temporary or permanent, especially after an especially severe case.
Glycolic acid: a key ingredient to target acne
Glycolic acid is perfect for oily skin that is prone to breakouts. Its keratolytic properties mean that it stops the build up of dead skin cells on the surface of the skin. Just with simple contact, no rubbing it in, glycolic acid can weaken the lipid bonds between the cells, getting rid of the layer of dead skin cells that builds up on the urface. This also helps to stop pores getting blocked and allows sebum to flow freely.
It also helps to regulate sebum production, which stops sebum from accumulating in your pores, the main issue behind acne. It’s known as the smallest of the alpha hydroxy acids (AHAs), which is why glycolic acid can easily move between your skin’s layers to work both on the surface of the skin and deep underneath.
Studies have shown that glycolic acid has antibacterial properties in an acidic pH environment of around 3 to 4.5, even at a weak concentration (<10%). This helps it to stop Cutibacterium acnes from multiplying on the skin of patients with acne, by disrupting the bacterium’s cell membrane. Generally, high concentrations of glycolic acid (>30%) are used to exfoliate the skin and unblock pores, whereas weaker concentrations (<15%) are used to prevent the build up which blocks pores.
Lastly, glycolic acid can brighten and even the skin tone. It reduces the appearance of acne scarring, as well as pigmentation marks. This is thanks to the role it plays in getting rid of melanin-saturated skin cells on the surface of the skin, and its ability to promote skin cell renewal, alongside its ability to inhibit excess melanin production, which stops pigmentation marks from forming.
KAWASHIMA M. & al. Glycolic acid chemical peeling improves inflammatory acne eruptions through its inhibitory and bactericidal effects on Propionibacterium acnes. Journal of Dermatology (2012).
TSANKOV N. & al. Drug-induced acne. Clinics in Dermatology (2017).
GARG V. K. & al. Comparative study of 35% glycolic acid, 20% salicylic–10% mandelic acid, and phytic acid combination peels in the treatment of active acne and postacne pigmentation. Journal of Cutaneous and Aesthetic Surgery (2019).
CHO N. J. & al. pH-dependent antibacterial activity of glycolic acid: implications for anti-acne formulations. Scientific Reports (2020).