How a cult skin-care product launched beauty’s buzziest category

I remember the first time I swiped on Biologique Recherche P50 ($67) toner as part of my beauty regimen. After regular use, my skin became brighter and my pimples became fewer. I can take it or leave it with regular toners, but the ones spiked with acids like P50? They are what skin-care dreams are made of. As a result, this cult-fave product has become a staple in zillions of beauty fanatics’ cabinets, and a whole lot of other beauty brands have taken note, meaning that there has been an explosion of acid toners onto skin-care shelves as of late.

The magic’s in the acid. Chemically exfoliating your skin, when done correctly, has the potential to keep dead skin cells away, your pores gunk-free, and your face looking bright and radiant. So packing some trusty chemical exfoliating acids into a toner—the step that comes between your cleansing and your serums—makes the products that are layered on after work even more effectively.

“Exfoliating acid-based toners are a smart method of removing dead skin cells and sloughing the superficial layers of the skin,” says Rachel Nazarian, MD, a dermatologist with Schweiger Dermatology Group. “Regular use can improve the texture of the skin and diminish hyperpigmentation and dark spots caused by ultraviolet radiation and pollution.” The other perk? “They offer a secondary level of cleaning that may not be achieved by basic cleansers for those who may need deeper removal of debris, such as people who wear heavy makeup,” she says. This can be particularly helpful for people with acne-prone skin, as it helps to get rid of every last bit of crap in your pores. If I had a dollar for every time my face dirtied a cotton pad after swiping on my toner (post-cleanse!), I’d be rich enough to create my own line of acid toners.

Chemically exfoliating your skin, when done correctly, has the potential to keep dead skin cells away, your pores gunk-free, and your face looking bright and radiant.

To perform this skin-enhancing magic, you’ll need a power combo of AHAs and/or BHAs. “Salicylic acid (BHA), glycolic acid (AHA), and lactic acid (AHA) are common ingredients in acid-based toners,” says Dr. Nazarian. You can pick and choose depending on your skin type or your skin’s needs. She says salicylic acid is the best if you’re acne-prone because it “works great to gently unglue the sticky cells that can lead to pimples.” Reach for glycolic if your skin’s on the sensitive side, though Dr. Nazarian says to use it conservatively. “Lactic acid is amazing for improving signs of sun damage including sun spots and fine lines,” she says.

These powerful toners aren’t just a fad, either. Acid toners are legit and derms and facialists are as fanatical about the stuff as I am. “I think they should be a staple in everybody’s skin-care regimen,” says Dr. Nazarian. “Although the type and frequency of use may vary depending on your skin type, chemical exfoliators are a necessary part of a regimen because skin cell turnover decreases with age and slows as we get older. Using chemical exfoliants is an easy way to keep skin looking fresh.”

With such power though comes some responsibility—AKA you’ve gotta be smart with your acid toner use. One too many swipes or choosing an option that’s too strong for your skin type can lead to over-exfoliation or compromising of your skin barrier. “I tell my clients to treat acid toners like red wine—one nightly glass is beneficial, more than that and you’re doing more harm than good,” cautions Angelina Umansky, a facialist and founder of Spa Radiance. “In moderation, acid toners can be an incredibly effective exfoliators and brighteners, while helping your serums and creams penetrate better. But there is a very thin line between productive exfoliation and stripping the skin.” A lot of people try to feel the burn or the tingle thinking it means the product works better, which isn’t necessarily the case. “You should see the results of an effective toner, not feel the results,” she says.

So choose wisely, and swipe on the acids that are right for your skin. Umansky’s advice? “I worship the house of the Biologique Recherche P50—the undisputed champion of acid toners,” she gushes. “It can be incredibly gentle—like the P50W for balancing and strengthening the skin—or aggressive, like the P50 1970 for oily skin. I consider it appropriate for everyday use.” While I’m also still on the P50 train—the OG in the category—I will say that with advances in skin-care ingredients these days, the competitors on the market are really good too. For your best skin ever, stock up on one (or several) of the below and thank me later.

Shop acid toners

Biologique Recherche P50 $67

Peach & Lily The Good Acids Pore Toner $39

SkinCeuticals LHA Toner $40

Alpha-H Liquid Gold $60

Moon Juice Beauty Shroom Exfoliating Acid Potion $39

Ren Ready Steady Glow Daily AHA Tonic $35

Pixi Skintreats Glow Tonic $15

Glytone Enhance Brightening Solution $37

Caudalie Vinoperfect Glycolic Brightening Essence $49

Mario Badescu Glycolic Acid Toner $18

Glossier Solution $24

Another must have for your skin-care regimen is a retinoid of some sort—here’s everything you need to know about retinol. And vitamin C serums are pretty damn good, too.