Demystifying Acids: How To Choose Between These Exfoliating Ingredients

@ 2024-10-15 16:48:19 -0700

Written by Carissa Zadwarny

Of all the skincare products one can hoard, acid exfoliants are hands down the most game changing to have in your routine. If you’re a skincare newbie, you might not know where to start with exfoliants and you’re definitely not alone. It’s easy to confuse AHA from BHA and salicylic with glycolic — I mean, the names on their own are hard, a tongue twister waiting to happen. We spoke to Dr Nancy Smolitis, MD, FAAD of facile dermatology + boutique and she gave us the full scoop on how to choose the right acid for your skin type. 

When it comes to dissecting the differences between glycolic, lactic and salicylic, Dr. Samolitis breaks it down. “Glycolic and lactic are in the chemical compound family known as alpha-hydroxy (AHA) and salicylic is a different family of acids, known as beta-hydroxy acids (BHA),” she says. While they’re different, they all have the same end goal. Each one is designed to stimulate chemical exfoliation (dissolving) of the superficial layer of skin cells. In other words, glowing radiant skin is a side effect of an effective acid working its magic.

She dives deeper, giving even more of a visual on how each one works to penetrate the skin. “AHAs are water soluble and that means they can only penetrate superficially into the top layer of skin. They release the bonds between cells allowing them to slough off which stimulates the skin to make new, healthy cells.” While most acids have the reputation of drying out the skin, that’s not always the case. “AHAs also are humectants meaning they enhance the natural hydration of skin,” says Samolitis. 

When it comes to addressing different skin concerns, each acid works to target specific issues. “Glycolic and lactic acid AHAs are most commonly used to treat signs of sun damage including dullness, brown spots, and dehydration,” explains Samolitis.

If you’re prone to redness, there’s one acid that works to treat this specifically. BHAs are oil soluble and that means that they can penetrate deeper into the pore where oil is produced. They also have anti-inflammatory effects reducing redness and swelling.

Although, there’s one that stands above the rest if you’re struggling with acne. “Salicylic acid BHA is most commonly used to treat acne because it can break down oil and dead skin cells that are clogging pores and reduce redness and inflammation that is commonly seen in active acne.” That’s why you’ll see this ingredient in many spot treatments specifically, since it’s so commonly used to stop zits in their tracks. 

For long-lasting results, Dr. Samolitis has one piece of advice, “When they are used regularly, acids promote smooth, glowing skin and can also stimulate new collagen production deeper in the dermal layer.” 

Samolitis also suggests that introducing acids that complement your skin type is of utmost importance in seeking the best results. “Someone with oily skin and acne would be best served by using salicylic acid, either in a cleanser or a spot treatment. The BHAs can penetrate more easily through oil. Glycolic acid is the smaller molecule of the 2 commonly used AHAs, so it will penetrate a bit deeper therefore providing faster results. It can be used in dry skin to enhance hydration.

If you’re more on the sensitive side, you should opt for a less harsh acid. “Lactic acid, a larger AHA molecule, only penetrates very superficially and is therefore the gentlest option for sensitive skin. 

If acids are new to your routine, Samolitis's advice is to go slow. “There may be a trial and error period to learn how your skin responds to acids, but most people will be able to find one that is compatible with your skin,” says Samolitis. It can be a bit unpredictable how your skin will respond to acids based on the amount of oil your skin naturally produces. Plan on possibly having some redness and dryness after using the acid and start with a single application and then wait a few days or even a week to see how your skin responds.

When using acids, it’s important to lay off the other harsh skin exfoliants. “Other active ingredients that stimulate skin cell turnover such as those in the retinoid family (OTC and Rx) may make your skin absorb the acid more quickly,” explains Samolitis. This isn’t necessarily a contraindication, but you will need to feel out your skin response. 

We couldn’t leave you hanging without Samolitis's must-have acids. Here are her top picks for getting those glowy skin results: