For some people, skincare is a second language. For others, beauty buzzwords are confusing and vague and they leave them feeling unsure and intimidated, especially when it comes to the varied categories of exfoliants. There's physical exfoliation, chemical exfoliation, AHAs, glycolic acid, lactic acid, and—okay, let's back up and go to square one. Consider this an exfoliation crash course.
Chemical Exfoliation and Peels
As we know, exfoliation is removing dead skin, debris, and pore-clogging material from the surface of the skin to reveal newer, brighter skin underneath. There are two different kinds of exfoliation: physical and chemical. Physical refers to anything with a slightly grainy or abrasive texture that you massage into your skin to manually remove buildup. Chemical exfoliation, on the other hand, utilizes safe-for-skin acids that break through debris and dead skin on a cellular level.
Chemical exfoliation can be further broken down into the specific acids that are used. "Acids work to improve skin by removing the top layers of the skin through weakening the lipids that bond them together, thus removing dull and dead skin cells and revealing healthy skin cells," says Dendy Engelman, MD, dermatologist, and director of dermatologic surgery at Metropolitan Hospital Center. These include lactic acid, salicylic acid, and glycolic acid. Though all are good options if used correctly, the latter is particularly effective, which seems to be why glycolic exfoliation treatments have exploded in popularity over the past few years.
Before we launch into the wonders of glycolic acid, know that the word "peel" pops up frequently. According to Carl Thornfeldt, MD, founder of Epionce, "A peel is any compound put on the skin to increase epidermal cell proliferation and remove stratum corneum and plugs within pores." Essentially it refers to the process of putting acid on the skin to exfoliate (acid that hasn't been mixed or diluted with other skincare ingredients).
Glycolic acid is a popular choice for a chemical peel, but there are many, many others that can be used. Take it from Yoon-Soo Cindy Bae, MD. She's a dermatologist, a clinical assistant professor at NYU Dermatology, and an associate at the Laser & Skin Surgery Center in New York. "Other acids that can be used include glycolic, lactic, mandelic, tartaric, malic citric, trichloroacetic, salicylic, carbolic, and so on. Some of these acids are used in combination as well and come in different strengths."
What Is Glycolic Acid?
Glycolic acid is an AHA, which is short for alpha-hydroxy acid (the name refers to its chemical makeup). Products featuring this active ingredient come in many different forms: cleansers, serums, moisturizers, eye creams, and facial peels, to name a few.
According to Cecilia Wong, founder of Cecilia Wong Skincare and a celebrity facialist, glycolic acid is made from sugarcane. This differs from other acids, like lactic acid, for example, which is made from sour milk. "Lactic acid is much milder and very gentle. The recovery time is faster, and it's a great option for sensitive skin." [Ed. note: Although lactic acid is a great exfoliant for sensitive skin, you shouldn't be so quick to write off glycolic.]
Krista Eichten, a licensed esthetician and vice president of products and services at Sanitas Skincare, says that glycolic acid reigns supreme as far as chemical peels go. "Glycolic acid is the gold standard in chemical peel formulations and is the go-to for many professional skin therapists for its proven ability to transform the health and appearance of a multitude of skin types," she says. This goes back to that chemical makeup we mentioned before.
"Glycolic acid has a small molecular structure, giving it the ability to travel deep into the layers of the skin," she continues. "Once there, the acid dissolves excess sebum and dead skin cells, revealing smoother, brighter, and younger-looking skin." Lactic acid, on the other hand, has a larger molecular structure. "This means that lactic acid is not able to penetrate as deeply into the layers of the skin."
That doesn't necessarily sound like a good thing, but it can be. "The benefit of this difference is that lactic acid is mild and it's more suitable for dry to sometimes even sensitive skin types. This is a favorite ingredient for brightening and also for exfoliating dry, sallow skin," Eichten says.
Glycolic Acid Skin Benefits
The benefits of undergoing a glycolic peel seem endless. Wong lauds it for stimulating natural collagen production, along with diminishing the appearance of fine lines and wrinkles over time. It's much more than an anti-aging product, though; glycolic acid also lightens discolorations such as sun and age spots. It can even help skin that's prone to blackheads, whiteheads, and acne by keeping pores clear of old skin that tends to clog them and cause problems. As Eichten mentioned, it penetrates deeply into the skin to reform texture and dullness. It leaves skin looking refreshed, bright, and refined.
Again, it all stems from its molecular size. Engelman says that glycolic acid is the smallest of all acids used in skin care. That's why it's able to penetrate so deeply and exfoliate so thoroughly. Take it from us: If it's used correctly (and you care for your skin correctly after the peel), it's a total miracle-worker for lending that effortless dewy radiance that usually seems to be exclusive to skincare experts and top models.
What's also notable is the fact that it's safe to use during pregnancy. "Glycolic acid is great for combating the hyperpigmentation that can occur from the hormonal surges that occur in pregnancy, called chloasma," Engelman says. "When I was pregnant, I used Elizabeth Arden's Skin Illuminating Retexturizing Pads ($56) with 5 percent glycolic acid. I would often wash with a gentle cleanser then use these as a treatment toner two to three times a week."
In-Office vs. At-Home Glycolic Peels
A glycolic acid peel done in a dermatologist's office is a quick and effective way to rejuvenate the skin. Dermatologists use a 30- to 40-percent concentration of glycolic acid, and it stays on your skin for only two or three minutes. These are often called "lunchtime peels" because they can be done easily during your break, with little downtime.
While the term "peel" makes the treatment sound harsh, it's actually quite gentle. You'll feel some tingling, but there's no burning, redness, or discomfort. (This video shows New York City dermatologist Dr. Neal Schultz doing an in-office glycolic peel in less than five minutes from start to finish.)
The benefit of doing an in-office peel lies in the higher concentration of glycolic acid, which ultimately leads to better results—but these come at a steep price. If you're on a budget and would like to see how your skin reacts before committing to an in-office peel, try an at-home glycolic acid peel like The Ordinary AHA 30% + BHA 2% Peeling Solution ($7).
Are There Any Side Effects?
There are a few things you need to know before booking your first glycolic peel or even if you're using glycolic chemical exfoliation products at home. "Chemical exfoliants used in conjunction with retinol or vitamin C can increase sensitivity and dryness. Overworking the skin with too many actives can start to break the bonds between healthy skin cells and thin the skin. Look for products with ceramides, hyaluronic acid, and peptides to strengthen the skin barrier," Engelman explains. In other words, hydrate, hydrate, hydrate post-treatment.
You also need to be wary of the sun. Glycolic acid can increase your skin's sensitivity to UV rays, so wear a hat, stay in the shade, and as always, use sunscreen in between treatments. It will protect your skin from harmful (not to mention aging) sun damage. La Roche Posay's Anthelios 60 Clear Skin Dry-Touch Sunscreen ($20) is lightweight and nonirritating.
According to Eichten, "It is common to experience redness, dryness, and peeling. Typically, immediately after the peel, the skin will feel tight and look red. With some, by day two to three, post-peel skin can begin to slough and shed. The level of peeling again depends on the intensity of the peel. With mild peels, expect gentle sloughing, and with stronger peels, skin can peel more dramatically. The complete turnaround time typically is between five to seven days. In this time, be sure to treat skin gently. Do not use any exfoliation products or devices, and it's imperative that precautions against UV exposure be taken to prevent hyperpigmentation."
And don't book a glycolic peel or even use at-home glycolic chemical exfoliation products back to back. "Excessive exfoliation can break down the stratum corneum—its job is to be a barrier against pathogens," Engelman says. "If the barrier function is damaged, skin becomes vulnerable to infection from microorganisms, such as bacteria and fungus, leading to sensitivity and irritation. Even if the barrier function isn't visibly damaged, the skin may experience a low amount of inflammation (called chronic inflammation), which prematurely ages skin over time."
Seek out a board-certified dermatologist or esthetician for an in-clinic peel. For at-home products, practice similar safe habits. "To ensure a great and safe peel, look for a glycolic acid level around 5 percent and a pH level between three and four," Eichten says. "Some favorites in our collection are Brightening Peel Pads ($74) and GlycoSolution 5% ($31). Incorporate glycolic acid slowly, as there is such a thing as too much of a good thing. Start by using two to three times per week. If excess drying or irritation occurs, cut back. "With continued use, skin will become stronger and healthier."