Salicylic acid. It’s everywhere. And chances are, if you’ve battled with acne, you’ve used it.
But here’s the thing:
For some people, salicylic acid is their savior. For others, it’s practically the devil.
In this post, we’ll examine the pros and cons of this oil-loving BHA (beta-hydroxy acid).
Before we get started, however, you should know what you’re getting yourself into. So let’s dive into a quick overview.
The pros of using salicylic acid are that it’s:
The cons of using salicylic acid are that it’s:
- Not safe to use during pregnancy
- Toxic in high concentrations
Without further ado, let’s get started.
PRO #1: It’s a Powerful Exfoliant
Your dead skin cells are supposed to shed on their own. But sometimes they need a helping hand.
Being a keratolytic, salicylic acid breaks down the glue that’s holding dead skin cells together, effectively speeding up the exfoliation process.
But salicylic acid doesn’t only work on the top layer of your skin. Since it’s lipophilic (aka attracted to oil), it travels deep within your pores to de-gunk them.
This might not mean much to you.
But think about it this way:
When your pores are clogged with oil, they stretch out. And when they stretch out, they look bigger than they really are. Degunking the oil with a lipophilic agent will make your pores appear smaller—at least temporarily.
Oh and there’s another cool thing you should know.
A study conducted in 2007 found that, even at the “wrong” pH, salicylic acid still exfoliates skin.
This is great news considering that a lot of the over-the-counter salicylic acid products don’t optimize their products for pH levels. (I’m guessing it’s because low-pH products can be irritating and companies don’t want to deal with a bunch of customer complaints.)
PRO #2: It’s Really Good at Treating Acne
As a comedolytic, salicylic acid treats mild-to-moderate acne by unclogging pores and keeping them unclogged.
Generally, there are two ways to use it:
- Mild at-home treatments
- Heavy-duty, in-office peels
The good thing about at-home treatments is that you don’t need a dermatologist for a prescription. Instead, you can head over to your local drugstore and find an endless supply of salicylic products at your disposal.
Even though over-the-counter products are limited to 0.5%-2% concentrations, studies have shown that they’re pretty good at diminishing acne.
Let’s take Stridex pads for example. Although they didn’t work for me (read my disparaging review here), a study conducted in 1981 found that they greatly reduced acne when used twice a day for a 12-week period.
A more recent study examined how a 1.5% salicylic acid cream could improve acne. Patients were required to apply the cream twice a day. And after 4 weeks time, 95% of patients saw improvements in their acne. Of those 95%, 20% experienced a complete clearing and 30% experienced significant improvements.
Of course, if you can afford a in-office treatments, more power to you.
Studies (like this one and this one) have shown that a series of 30% salicylic acid peels can have a dramatic impact on both inflammatory acne (i.e. pustules) and non-inflammatory acne (i.e. blackheads).
And that’s not all.
When compared to glycolic acid peels, one study found that salicylic acid peels had longer lasting results (2 months after treatment). Not to mention, they had fewer side effects than their counterpart.
Salicylic Acid Vs. Benzoyl Peroxide for Acne
Both salicylic acid and benzoyl peroxide are the OG’s of the acne game. So it makes sense that these they’re constantly being compared to one another.
If you’re familiar with these ingredients, you might think that benzoyl peroxide has a leg-up on salicylic acid. You know, since it kills acne-causing bacteria (otherwise known as P. acnes).
But that’s not the case.
Studies have shown that salicylic acid performs just as well as—if not better than—benzoyl peroxide when it comes to treating acne:
- A 4-week study compared a 2% salicylic acid cleanser to a 10% benzoyl peroxide cleanser on 30 acne patients. The patients that started with the 2% SA cleanser saw significant improvements within just two weeks. But somewhat regressed when, in the final 2 weeks of the study, they switched to the 10% BP cleanser.
- A split-face study compared a 2% salicylic acid cream to a 5% benzoyl peroxide + .1% adapalene cream. After 28 days, researchers concluded that there were no significant differences between the two creams—both creams actually reduced acne by about 40-50%.
- A 12-week double-blind study compared two creams—a 5% benzoyl peroxide cream and a 2% salicylic acid + 0.5% chloroxylenol cream. At the end of the study, researchers concluded that there were no statistical differences between the two groups. However, salicylic acid was better tolerated, especially in terms of photosensitivity and redness.
Oh and there’s one more thing worth mentioning:
Benzoyl peroxide bleaches fabric. Salicylic acid doesn’t.
So if you covet your clothing, this is another reason to choose SA over BP.
PRO #3: It Has Anti-Inflammatory Properties
Have you ever Google searched “acne home remedies”? If you have, you’ve probably been told to crush aspirin, mix it with water (until it forms a paste), and apply it to your pimple.
Well, as it turns out, aspirin (otherwise known as acetylsalicylic acid) and salicylic acid are related. Both are salicylates and, as such, both have anti-inflammatory properties.
Pro tip: Personally, I wouldn’t recommend using aspirin to quell acne—it wasn’t made to be used as an acne treatment so it might irritate your skin. Salicylic acid products, however, were made for acne, so using these products can bring down inflammation without any unforeseen side effects.
PRO #4: It’s Photoprotective
Exfoliants remove part of the protective layer that’s sitting on top of your skin. And in a lot of cases, they can make your skin more sensitive to the sun.
But studies have shown that salicylic acid has the opposite effect.
In other words, adding it to your skincare routine can protect you from sun damage.
One study, in particular, examined how chemically exfoliated skin reacts to artificial sunlight. To do this, they compared three creams—a 10% glycolic acid cream, a 2% salicylic acid cream, and a control cream. Each cream was applied once-a-day for 3 and ½ weeks.
After this period, the treated areas were tested for things like redness, sunburn cells, and DNA damage. It was discovered that glycolic acid (an AHA) increased all three of these markers. But salicylic acid didn’t. Its results were similar to the control cream.
The National Toxicology Program conducted a similar study. Again, they compared the effects of glycolic acid and salicylic acid on sun-exposed skin—except this study was conducted on mice.
The mice treated with a 4% salicylic acid cream were less likely to develop carcinoma in situ, a type of skin cancer. And the researchers concluded that salicylic acid has some photoprotective effects.
Pro tip: Just because salicylic acid is slightly photoprotective, doesn’t mean it’ll completely protect you from UV damage. Wearing sunscreen and protective clothing are pretty much the only ways to adequately protect you from things like sunburns, skin cancer, and premature aging.
CON #1: It Can Cause Dryness and Irritation
The main reason why people dislike salicylic acid is that it can be incredibly drying. This is especially true for sensitive skin types.
How many people find it irritating?
A survey-based study concluded that 43% of its participants reported dryness and 31.1% of its participants reported flakiness after using an over-the-counter salicylic acid product.
On a personal note, the more I use salicylic acid, the dryer I become. And eventually I’m left with red, splotchy, over-exfoliated skin (check out some signs and symptoms of over-exfoliated here).
Pro tip: If you know you have sensitive skin and you still want to use salicylic acid, try a facial cleanser. It’s an easy way to reap some of SA’s benefits and it’s not likely to be irritating. Plus, research (like this study) has shown that salicylic acid cleansers can, in fact, reduce acne.
CON #2: Pregnant Women Should Stay Away from It
Salicylic acid is labeled as a “Category C” ingredient by the FDA.
Being a “Category C” ingredient isn’t necessarily a bad thing.
It just means that there aren’t any studies regarding its use during pregnancy.
The reason why salicylic acid was placed in this category is because of its relationship to aspirin. It’s well-known that taking aspirin orally can cause birth defects.
So the FDA errs on the side of caution when it comes to topical applications of salicylic acid—especially since topical applications can be absorbed by your skin.
I’ve read some articles that say that low doses in short durations are okay. But personally, I wouldn’t risk it.
CON #3: It’s Toxic in High Concentrations
According to an article on Clinical, Cosmetic and Investigational Dermatology, “In dermatological practice, salicylate toxicity has been reported when 20% SA is applied to 50% of the body surface area.”
Salicylate toxicity isn’t something you want to mess around with. It can cause things like:
- Organ failure
Most people use low concentrations of salicylic acid on their face only. And in this case, toxicity is not likely. But if for some reason, you decide to venture out into other body parts, please do so under medical supervision.
How To Use Salicylic Acid (OTC)
When adding salicylic acid to your skincare regimen, it’s important to start slow. Find a low concentration product and use it every few days. If your skin reacts well, you can start using higher concentrations with greater frequency—2% concentrations can be used twice daily at most. If your skin reacts poorly, ditch the product immediately.
Since leave-on products can be harsh on skin, some people prefer to apply a salicylic acid toner and wash it off after 5-30 minutes.
Whatever you do, make sure to immediately follow-up with a moisturizer. As this will help keep your skin hydrated.
Caution: It’s generally not recommended to use multiple exfoliants—like AHA’s and retinoids— at once.
To sum it up, salicylic acid is a well-tolerated ingredient. Its pros are that it:
- Exfoliates skin and degunks pores
- Diminishes acne just as well as, if not better than, benzoyl peroxide
- Acts as an anti-inflammatory agent
- Protects your skin from the sun’s harmful rays
Of course, salicylic acid isn’t perfect. Its cons are that it:
- Causes dryness and irritation in about 40% of users
- Might have some side effects if used during pregnancy
- Toxic if high concentrations are used on 50% of your body