Exfoliating acids in skincare have gained popularity over the past few years—and for good reason! Acids are multifunctional, because they’ve been shown to improve mild acne, fade hyperpigmentation, boost collagen production, smooth fine lines and accelerate your cell turnover rate to promote a brighter, more refreshed appearance.

So, what are acids, anyway?

Acids are a skincare ingredient used to exfoliate. They work by loosening the fluid that binds the cells to the upper surface of your skin. This leads to increased shedding of the upper layers of your complexion, leading to a smoother, brighter tone.

Let’s Talk About Alpha Hydroxy Acids (AHAs)

Of all the different acids on the market today, alpha hydroxy acids (AHAs) are the most effective—and the most irritating. AHAs are water-soluble and work mainly on the outermost layer of the skin. The top AHAs include Glycolic Acid, Lactic Acid, Mandelic Acid and Fruit Acids, also referred to as Multifruit AHAs. Let’s take a closer look at a few of these…

Glycolic Acid

Derived from sugar

Smallest molecule of all the acids

Penetrates the deepest and works the best

Increased risk of irritation and sun sensitivity

Regenerates collagen production

Evens skin tone and texture

Smooths fine lines and wrinkles

Lactic Acid

Derived from sugar or fermented milk

Second smallest molecule

Gentler than glycolic, which makes it a moisturizing agent, too

Good for those with sensitive skin

Smooths and evens rough skin

Fruit Acids

The gentlest option

Citric-derived from lemon or grapefruit, and malic from apples

Largest molecule

Works mainly on the uppermost layer of the skin

Gentle enough for daily use

Star ingredient in The Multitasker Night Serum 1(5% Multifruit AHA)

May be combined with stronger acids, such as glycolic or lactic

Used once or twice a week

Let’s Talk About Beta Hydroxy Acids (BHAs)

BHAs, aka beta-hydroxy acids, are considered oil-soluble, which means they penetrate deeper into the pores, allowing them to work better for oily, acne-prone skin. They also have anti-bacterial and anti-inflammatory properties which help to dissolve excess oil in the pores. So, as you can imagine, BHAs are great for those who suffer from mild acne, clogged pores, white heads and blackheads.

The most common BHA is Salicylic Acid—which is best known for its success in treating acne. It penetrates and dissolves oil-clogged pores, exfoliates dead cells and also has anti-inflammatory properties!

Skincare Acid Safety & Frequency of Use

The two main concerns of overusing AHAs is increased sun sensitivity and irritation. Over time, these can cause damage to the skin barrier. BHAs are typically reserved for less frequent use or only for those treating acne.

If you’re using AHAs for skin rejuvenation, evening skin texture and preventing mild breakouts—it’s best to use a gentler AHA, such as fruit acids, on a daily basis. From there, you’ll want to add a stronger combination of glycolic, lactic and salicylic acid one to three times a week, depending on your tolerance.

The bottom line? Acids work quickly and efficiently to achieve healthy, glowing skin—which can be addictive. Unfortunately, overuse can result in the opposite effect. Acids have a meaningful place in your skincare routine, but you need to know how and when and which type of acid to use.

Need a hand? Here’s an example of what my nighttime skincare routine looks like:

Step One: Wash with Otto’s gentle hydrating cleanser, The Good Day Face Cleanser (2% ceramides)

Step Two: Swipe on a few pumps of Otto’s fruit acid and niacinamide serum, The Multitasker Night Serum (15% multifruit AHA + 7% niacinamide)

Step Three: End by smoothing on Otto’s vitamin C face oil, The Fresh Start Face Oil (20% tetrahexyldecyl ascorbate)

Step Four: Use a stronger glycolic, lactic or salicylic acid product one to three times a week, or as needed

Skincare Product Recommendations with Acids

Otto Skin Goods The Multitasker Night Serum (15% Multifruit AHA + 7% Niacinamide)

Shop Now ($65)

Kinship Insta Swipe: Gentle AHA Exfoliating Pads

Shop Now ($26)

Dermatologist’s Choice: Glycolic Peel Cleansing Pads

Shop Now ($65)

First Aid Beauty: Facial Radiance Pads with Glycolic + Lactic Acid

Shop Now ($38)

Pixi Beauty: Glow Tonic To-Go Exfoliating Toner Pads

Shop Now ($18)