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I haven’t done an ingredient matchup in a while because the last one was two ingredients that were both so similar — every skin condition was “well they’re both good for this but in slightly different ways”. Which is not very fun to read and honestly quite difficult to write! So let’s get going on a new ingredient matchup post with two ingredients that are actually quite different. 

So, depending on your skin, either azelaic acid vs benzoyl peroxide will make a big difference. 

So, as always in these posts, these ingredients are being explained so that a normal person can understand them and then move on with her day — you don’t need to be a board-certified dermatologist to read these posts. 

What is azelaic acid?

Okay, so azelaic acid is an acid, but not like that!  It’s not at all like  glycolic acid peels. It’s not an AHA (alpha hydroxy acids) that is going to slough away dead skin cells. It’s also not a BHA (beta hydroxy acid) that is dissolving oils from the skin. (Technically it’s a “dicarboxylic acid” but we aren’t going to worry about that.) 

Think of it as an active ingredient, not an exfoliant, that happens to be faintly exfoliating. More like how hyaluronic acid is tehnically an acid but doesn’t behave like one. 

So what does it do?

• An azelaic acid serum is just barely exfoliating the skin, so it helps to unclog pores but does not give you that “exfoliated” skin effect. It will also gently reduce dark spots. 
• It also has antibacterial properties, so acne-causing bacteria will be decreased if you’re using it. 
• Azelaic acid products will soothe redness from skin irritation, acne, or rosacea. 

So azelaic acid is a great ingredient if you’re looking for calming skincare. It exfoliates a little, but not too much, and kills bacteria, but not too harshly, and reduces inflammation, but not in a way that leads to more inflammation later. 

It’s a great routine backbone — what it doesn’t tend to do is big sudden dramatic results. 

What is benzoyl peroxide?

Benzoyl peroxide products are generally acne treatments. They’re a topical treatment that can be used to treat mild acne to severe acne and reduce acne breakouts. The way it works is by killing the specific bacteria, p acnes, that causes acne. 

(You might also remember that there was a TikTok trend a while back to use a benzoyl peroxide cream as a deodorant once a week in the shower — this works basically the same way. The benzoyl peroxide kills the bacteria that cause odor in your underarms. I did this for a while and then stopped because I found it was bleaching my clothes no matter how carefully I scrubbed it out after!)

So if you have acne-prone skin and acne treatment is on your radar, you’re probably familiar with benzoyl peroxide. 

I’m old enough to have used Proactiv throughout my teen years (imagine that gif of Spongebob gasping for water, only it’s my teenage skin) that used a ton on benzoyl peroxide in its three-part treatment system. It was very, very drying, it had a bleaching effect on every towel in my mom’s house, and it resulted in shockingly dry skin, but it did improve my acne. 

And modern products are a lot gentler! I don’t bring up Proactiv to scare you off! If you’re experiencing acne, benzoyl peroxide is a cheap and effective over-the-counter acne treatment. It is drying, but not so drying that you can’t counterbalance it in the rest of your skincare routine. It does create free radicals in the skin, so it is best to figure out the minimum frequency of use that you can get away with. That is, don’t use it twice a day if once a day is going to keep your acne away! Or, if using it every other day is enough, limit it there. Similarly, use a lower concentration if you can. 

But, benzoyl peroxide is generally the first-stop acne treatment because it works! If you have been using benzoyl peroxide and it isn’t working for you at all, you should swap it for Nizoral to test if you have fungal acne. 

The people who need to limit benzoyl peroxide are sensitive skin types and MOST people with rosacea-prone skin (we’ll get back to that). Benzoyl peroxide can be an irritating ingredient, and it may not work for everybody. Sensitive skin types with acne may do better starting with salicylic acid to see if their acne is related to excess oil. 

Which is the better choice for acne?

If you’re experiencing acne, benzoyl peroxide is going to get you the results you’re looking for faster. It’s one of the cheapest and most effective acne products. 

The face wash is a lot less harsh! 

 

And if you only have a few pimples at a time, you can try using a spot treatment rather than an allover treatment, which might help you manage dryness. 

So for treatment of acne, I would love to tell you “start with every third day and only increase if you need to”, but I know that’s not realistic. When you’re living with acne, you want to see it gone RIGHT AWAY. So, go ahead and use it once a day for a week or so. 

Mini-routine for treating acne with benzoyl peroxide

• At first: Use benzoyl peroxide wash every night for 7-10 days. Night is important, because benzoyl peroxide will make you sensitive to the sun. Use sunscreen! Use simple, hydrating products like hyaluronic acid and ceramides to balance dryness. 
• Once you have seen improvement: Start figuring out how much you can reduce the benzoyl peroxide without giving up your results. First, skip the wash every third day, then every other day, and so on. Many people will find that using benzoyl peroxide 1-2 times per week is enough! If your acne begins to worsen, you’ve reduced too much and should go back a step.  

​What about azelaic acid for acne? 

If your acne is mild, azelaic acid may address it without dryness! It’s not a powerhouse for stubborn acne like benzoyl peroxide is. But many people may prefer to use azelaic acid because harsher acne ingredients lead to inflammation or irritaiton. Azelaic acid works more slowly but will have fewer side effects, and it contributes to the long-term health of your skin.  It still has antimicrobial properties, and you get all the other benefits of azelaic acid.

Which is the better choice for rosacea?

Okay, this one gets a little messy. Stay with me. 

Benzoyl peroxide is a terrible choice for people with rosacea UNLESS it’s papulopustular rosacea, the kind where you get big cysts. 

“Classic” rosacea where your cheeks are red and you get broken vessels is erythematotelangiectatic rosacea–I call it ET in my head. This is the type that I have. Benzoyl peroxide is way too irritating for this type — we can’t tolerate harsh skincare products like that. 

But for the papulopustular type, they do need acne treatment. And any rosacea phenotype can get acne! So there’s some demand for benzoyl peroxide for us!

So here’s my advice: 

Start with azelaic acid​. It’s anti-inflammatory, and it does address acne-causing bacteria. It’s also super soothing, which is good for any rosacea sufferer. And if you have a dermatologist, they can even prescribe you stronger, prescription azelaic acid gel or foam that might be enough to help your acne! 

If you feel you need benzoyl peroxide, ask your derm about microencapsulated benzoyl peroxide first​. This is a newish but effective treatment that’s safe for rosacea sufferers! It’s been found to be much less irritating, and it might be a great choice for either papulopustular rosacea, or for another type of rosacea where the person also has acne. 

Which is the better choice if I want glass skin, or for anti-aging?

Benzoyl peroxide creates free radicals, so it’s aging your skin. No two ways about it. 

So if you’re not dealing with acne, skip the benzoyl peroxide. If you’ve been using it since you were 13 and now you’re 29, see if you can stop using it without any acne flare-ups. If you are using it and you need it, reduce it as much as you can and see if you can get it down to once or twice per week. Keep it in perspective — it’s not the worst thing in the world. But you don’t want to use more than you need. 

Azelaic acid on the other hand is a great choice for anti-aging and glass skin — it’s going to encourage your skin cell turnover and improve skin texture, and because it gently exfoliates it also addresses the sun damage and post-inflammatory hyperpigmentation that tends to accumulate as we age. Because inflammation is aging, azelaic acid can also prevent skin aging, not just treat it. So the anti-inflammatory properties of azelaic acid are super beneficial for skin anti-aging. 

It’s rare to get azelaic acid on its own — most formulations are going to have additional ingredients that are also focused on hydration, which is going to compound with the benefits. I like the Naturium for the other anti-aging actives that are stacked with it: 

This is a great product and an affordable way to try azelaic acid, but be prepared for the small bottle! But it’s a really good choice to try the ingredient out. It’s a great, skin-healthy, long-term ingredient that will address skin tone and fine lines.