Benzoyl Peroxide vs. Salicylic Acid: What's The Difference & Which Should You Use?
Becoming well-versed in the glossary of acne-fighting ingredients, we admit, is no walk in the park (the acids alone can be dizzying). But when those pesky blemishes pop up, you don't want to slather on any ol' ingredient and hope for the best—you need to make an informed choice based on your skin type.
There's no shortage of treatments to choose from, but let's start with two of the most popular: benzoyl peroxide and salicylic acid. They're often conflated, so it's important to know just when and how to use both of these powerful ingredients (hint: It depends on the type of acne you have).
What is benzoyl peroxide?
Like its cousin, hydrogen peroxide, benzoyl peroxide is antimicrobial—meaning it can kill acne-causing bacteria. But while you should probably steer clear of using hydrogen peroxide for acne (short answer: It's way too harsh for your skin), there's tons of research touting the latter as an effective acne treatment.
- Pros: "It kills the acne-causing bacteria, P. acnes, that lives within our hair follicles, and it also helps to break up and remove dead skin cells that clog our pores," explains board-certified dermatologist Ife J. Rodney, M.D., FAAD, founding director of Eternal Dermatology + Aesthetics. That means the acid can be helpful for both inflammatory acne (your angry pustules, cysts, and pimples) as well as comedonal acne (blackheads and whiteheads).
- Cons: However, some might find benzoyl peroxide to be rather drying. "Skin dryness and irritation are the most common side effects," Rodney mentions. Especially for those with sensitive skin, you might face some burning, redness, stinging, and skin peeling. It makes sense: Peroxide has the ability to bleach fabrics, so it's understandable the ingredient might be too harsh for some sensitive-skinned folk.
What is salicylic acid?
Salicylic acid comes from the beta-hydroxy acid (BHA) family. In case you need a refresher on those lovely BHAs, these acids are oil-soluble, meaning they can penetrate deep into your pores and unclog them at the source. Salicylic acid is a popular choice, as it can gently dissolve dead skin cells by breaking apart the bonds that hold them together, promoting cell turnover and smooth, bright skin underneath.
- Pros: BHAs like salicylic acid are great for reducing blackheads, whiteheads, and milia (aka comedonal acne). Plus, they typically do so in a nonirritating way: "BHAs also have anti-inflammatory, skin-calming properties, so they are gentle enough even for sensitive skin prone to redness and/or rosacea," notes board-certified dermatologist Hadley King, M.D. Another added benefit? Rodney mentions salicylic acid can help prevent post-inflammatory hyperpigmentation, especially for those with darker skin tones.
- Cons: While salicylic acid is great for unclogging pores, it won't necessarily help with inflammatory acne or pustules. It doesn't have antibacterial properties, like its benzoyl peroxide counterpart, so it won't necessarily shrink down those angry, inflamed pimples.
How to decide which you should use.
Let us emphasize: Every product is different, so there aren't too many hard-and-fast rules. For example, benzoyl peroxide products (which tend to be more drying) might come buffered with hydrating actives to simultaneously lock in moisture while shrinking pimples in size. Similarly, salicylic acid might be paired with AHAs in combination treatments to further resurface the skin, which can actually cause irritation for some. See the nuance here?
But generally, here's how to decide when to use both:
- Identify what type of acne you have: Time to I.D. your acne in the mirror. Are your bumps painful or underneath the skin? Or do they come to a head on the surface? For those angry pustules, you might want to reach for a benzoyl peroxide spot treatment (if you can tolerate it, of course). For blackheads and whiteheads, salicylic acid can unclog those pores. While benzoyl peroxide technically can help with comedonal acne, it's mainly hailed for shrinking inflammatory pimples.
- Check your other skin care products: Before diving straight into either treatment, you'll want to check your skin care lineup to make sure there aren't any ingredients that can irritate your skin or cancel out. For example: "When benzoyl peroxide and retinoids (or retinols) are used at the same time, they may interact and make them both less effective," Rodney mentions. If you do use retinol, she recommends sticking to a benzoyl peroxide face wash in the morning, so you can apply retinol at night, and the two won't interact. Win-win.
- Mind your skin type: "While both of these ingredients have the potential to dry out and irritate the skin, I find that there are more people who experience redness and irritation from benzoyl peroxide," says King. Of course, every person is different—your skin might be totally fine with benzoyl peroxide, especially if the product also contains calming ingredients. But as a general rule, those with sensitive skin might fare better with a gentler salicylic acid treatment, especially if you're also prone to oiliness and clogged pores.
Both benzoyl peroxide and salicylic acid are solid acne-fighting ingredients—it just depends on the type of acne you have. Your skin type also matters when choosing a treatment, as do the other skin care products in your routine, but the general verdict is this: For inflamed zits, an antibacterial benzoyl peroxide product is best (seek options buffered with hydrating actives to combat the drying effects); for pesky blackheads and whiteheads, oil-soluble salicylic acid is your guy.
Shop these products:
Kinship Pimple Potion Retinal + Salicylic Acne Treatment
KLUR Stellar Restoration Corrective Complex
Glytone Acne BPO Clearing Cleanser
La Roche-Posay Effaclar Duo Acne Treatment With Benzoyl Peroxide
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