Learn the differences between the two acne-fighting ingredients and how to use them.

Pimples are something everyone can relate to. Whether you've had consistent hormonal acne since middle school (like me!) or you're one of the lucky bunch who just gets one or two every once in a while, we've all had 'em. And when we do, we want them to go away. Like, yesterday.

When it comes to OTC acne treatments, there are two specific ingredients that work best to zap even the worst zits: salicylic acid and benzoyl peroxide. Both attack acne-causing grime and bacteria; however, that's about where the similarities end.

To find out more, we asked two dermatologists, Harvard-trained Dr. Michelle Henry and Dr. Anna Karp, a Clinical Instructor at NYU's Grossman School of Medicine, and a private practitioner, to share their knowledge of the two ingredients and how to know which one is right for you.

What Is Salicylic Acid?

Salicylic acid is the more well-known acne-fighting ingredient of the two, likely due to the fact that it's been on the market for a bit longer, but also because it can be found across the spectrum of acne-fighting skincare products, from spot treatments to all-over formulations.

"Salicylic acid is a beta hydroxy acid that is both highly keratolytic and comedolytic," says Dr. Karp. "Which means it not only dissolves dead skin cells on the surface of the skin, but it's also able to get down into the pore, dissolve the oil and break apart the debris inside that commonly leads to acne."

Another bonus feature of SA is that it's oil-soluble, so it can cut through even the oiliest skin types to reach pores and get straight to work.

What Is Benzoyl Peroxide?

"Benzoyl peroxide kills bacteria on the surface of the skin," explains Dr. Karp. "It also decreases inflammation in acne lesions."

The antiseptic can be found in skincare at various strengths, beginning as low as 2.5%, all the way up to a 10% formulation, depending on the severity of the outbreak.

Another pro? "There haven't been reports of antibacterial resistance," adds Dr. Henry, meaning that your skin won't build a tolerance to it over time. So it will always be effective, even if you use it every day.

What Are The Differences Between Salicylic Acid and Benzoyl Peroxide?

Although both products are acne superheroes, they each target different sources of acne-causing gunk. Salicylic acid works as an exfoliant below the skin's surface to focus on the root causes of acne, while benzoyl peroxide stays on the surface.

"Benzoyl peroxide might be slightly more likely to cause skin dryness," says Dr. Henry, who also notes that it "works a bit faster than salicylic acid," taking up to four weeks to show results.

"Benzoyl peroxide is especially good for more inflammatory acne that is usually colonized by bacteria," says Dr. Karp, while salicylic acid does its best work on blackheads and whiteheads.

Should I Use Salicylic Acid or Benzoyl Peroxide?

"They are both quite effective against acne and the decision to choose one over the other should be based on skin type, ingredient concentration, and the type of product you are using," says Dr. Henry. "If your skin is particularly sensitive or tends toward being dry, I would start with a low concentration salicylic acid, as it can also be somewhat anti-inflammatory, and a benzoyl peroxide spot treatment."

VIDEO: How to Properly Cover A Pimple

Can I Use Both Salicylic Acid and Benzoyl Peroxide Together?

"It's safe to use both together at low concentrations to attack your acne on all fronts," the dermatologist explains.

However, sensitive skin types should be especially mindful of the concentrations of both products if used in tandem, cautions Dr. Karp, and avoid layering one on top of another.

What Are the Cons of Using Salicylic Acid and Benzoyl Peroxide?

In addition to benzoyl peroxide's drying effect on the skin, the higher concentrations also have a tendency to bleach dark fabrics.

"Don't wear your favorite pajamas to bed when using benzoyl peroxide," jokes Dr. Henry. But really, be extra cautious when wearing dark colors.

Can I Use Salicylic Acid and Benzoyl Peroxide For Body Acne?

"Both can be used to treat body acne," says Dr. Karp. "A 10% benzoyl peroxide body wash like Panoxyl works well on back and butt acne," which she says is very common, even if people aren't admitting it.