Your Guide to Benzoyl Peroxide by a Medical Esthetician

This is your guide to understanding benzoyl peroxide, how it works, and how to make it work for you and your skincare routine, especially if you have acne. 

What is benzoyl peroxide?

Contrary to popular opinion, benzoyl peroxide is not an exfoliant nor is it an antibiotic like the ones you might get prescribed from a doctor or dermatologist. Benzoyl peroxide simply introduces oxygen into the skin, and this is how it kills acne bacteria. Acne bacteria or cutibacterium naturally live inside of our skin, and it lives in an anaerobic environment or oxygen-less environment. Acne bacteria can’t exist in the presence of oxygen. And likewise, when benzoyl peroxide gets heated up, it releases oxygen. Naturally, your skin is warm, and when benzoyl peroxide travels into your warm pores, the bonds breaks, it releases oxygen, and then, it kills the acne bacteria. 

How does benzoyl peroxide actually work?

You can find benzoyl peroxide in different cleansers, but it works best within leave-on treatments. 

Benzoyl peroxide leave-on treatments help to clear up the skin, and it can do so quickly. Now, unfortunately, benzoyl peroxide can be a little irritating or drying for some people. That’s why it’s always important to make sure you’re using the right formula and the right amount. There are different concentrations of benzoyl peroxide that range from .5% to 10%, or if prescribed by a doctor, it can even come in percentages of 60%. (Dermatica also has the option of prescribing benzoyl peroxide). 

But, for those who have sensitive skin, Cassandra recommends using benzoyl peroxide in a wash-off formula rather than a cream or serum. Using benzoyl peroxide in a wash-off formula can be wonderful because you reach your chest and back and they're great for simple body acne routine. 

What skin type is benzoyl peroxide for? 

Usually, skin that is a little bit more resilient or oily tolerates benzoyl peroxide the best. If you are dry or prone to irritation, you probably don’t want to use any of the leave-on forms. Also, there are some people who are allergic to benzoyl peroxide. If you are allergic to benzoyl peroxide, your face might get unreasonably red or swollen. In this case, you should back off, see a doctor, or talk to a derm.

On the other hand, if your skin is just sensitive, you might want to use benzoyl peroxide in a wash formula, that way it’s not staying on your skin. Some of Cassandra’s favorites are very inexpensive. The PanOxyl Drugstore cleansers are very inexpensive, and you can get it in a 5% or 10%. 

Then, The Inky List actually has The Super Solution Cleanser


The Super Solution Cleanser - $17.99


This Inkey List actually has super solutions. This is really expensive, and this is fantastic for teenagers, acne, and people with oily skin who to simplify their routine. This is great to use in the shower once a day. You can also use it on the chest in the back. 

Dr. Sandra Lee MD Benzoyl Peroxide Lotion - $30

Now, if you are more oily or your skin is more tolerant, this is a great product. This is the benzoyl peroxide acne lotion at 2.5%. If you want a higher percentage, one of Cassandra’s favorites is Dermatica.

Dermatica is custom blended to each person. So, what you get is going to be different than what Cassandra gets. While Dermatica offers benzoyl peroxide, they also offer things like vitamin C, adapalene, tretinoin, and clindamycin.

So, can you mix ingredients like these with benzoyl peroxide ? Let's cover it.

Ingredients not to mix with Benzoyl peroxide

Vitamin C

This biggest no-no is actually vitamin C. This combination probably won't cause major damage to your skin. It's just that the two ingredients basically cancel each other out. While vitamin C is an antioxidant, benzoyl peroxide introduces oxygen AKA free radicals into the skin and kills the acne. So, when you combine the two, they cancel each other out. 

So, if you want to use both, make sure you’re using them at separate times of the day. For example, you can use vitamin C in the morning and benzoyl peroxide at night. You can use a benzoyl peroxide cleanser at night or a normal cleanser with a benzoyl peroxide treatment at night.

Retinoids. It depends on the circumstance.

If you mix benzoyl peroxide with retinoids, it can cause irritation and more dryness. So, unless it’s prescribed by a doctor or derm, take it slow, don’t mix these together, or use them at the same time. 

However, there are exceptions to this. For example, there is a medication called Epiduo. Epiduo is a form of retinoid plus benzoyl peroxide, and it truly works great for acne. It’s a prescription, and Dermatica does have custom blended formulas like this. However, attaining something like through Dermatica will not be as simple as requesting. With Dermatica, a doctor or a provider will prescribe what works best for you. If you decide to use benzoyl peroxide and a retinoid together by yourself, use one product at a time, and use lower concentrations That way, your skin won't be as like to red and peel..

Ingredients you can mix with Benzoyl peroxide


There are plenty of antibiotics out there like tetracycline, doxycycline, monodoxidil, and clindamycin. Clindamycin is used topically on the skin. And even though it's not drying, it is still an antibiotic that helps to kill and dry out bacteria.

Clindamycin needs to be prescribed by a doctor or derm. So, if you’re truly struggling with acne, speak to your provider, or go to a pharmacy like Dermatica. Ask one of the doctors there if it would work for your skin because sometimes over the counter stuff just doesn’t cut it.

Of course, you’ll want to talk to your derm, but if you’re using any topical antibiotics on your skin, your derm has probably recommended using a benzoyl peroxide wash too. While antibiotics kill acne bacteria, you can also can use a benzoyl peroxide wash to kill any bacteria that tries to come back and resist those antibiotics. Whether you use them together or not though, both ingredients need to be worn with a sunscreen. 


When should I use benzoyl peroxide? 

Benzoyl peroxide is not excessively photosensitive so you can use it in the morning or the evening. You could use it twice a day, but usually once a day is more than enough especially if you don’t have oily skin. If your skin is super sensitive, you might want to start once or twice a week and then build up.

How long does benzoyl peroxide take to work?

If you’re using OTC benzoyl peroxide, you usually start seeing results in about a month or two. If you’re using it in combination with a prescription, the results might be a little faster like 2-3 weeks to a month. But even so, if your skin has a slower turnover rate, it could take longer.

Be patient with your skin, and remember that it’s a work in progress! Also, remember that you should still be gentle if you have acne. You are not required to use harsh actives on your skin. Including these choices, there are a bunch of cleansers that truly help to cleanse the skin without intense actives. 

Glow Recipe Avocado Ceramide Moisture Barrier Cleanser: - $28


Dermatica Balancing Glycerin Gel Cleanser - $14.95