If you have mild to moderate acne, one of the first treatments your doctor or pharmacist will recommend is benzoyl peroxide. Benzoyl peroxide (also known as BPO or BP) has been used for treating acne since the 1930s, and it’s still going strong! Here’s why:
How Does Benzoyl Peroxide Fight Acne?
Benzoyl peroxide is a powerful antimicrobial
Benzoyl peroxide kills bacteria by reacting with bacterial membranes (via oxidation and free radical mechanisms). The beauty of benzoyl peroxide compared to traditional antibiotics is that bacteria can’t become resistant, and it actually works more effectively than antibiotic creams too! BPO is often combined with other acne treatments for these reasons.
It dissolves in oil
Benzoyl peroxide dissolves well in oil (it’s lipophilic), which means it can penetrate deep into pores and pimples.
Anti-comedogenic properties
You don’t often see it listed as an exfoliant, but benzoyl peroxide is actually fantastic at loosening skin cells deep in the outer layer of skin (stratum corneum), deeper than salicylic acid can reach.
Anti-inflammatory action
Benzoyl peroxide also reduces inflammation, an important contributor to the development of a proper breakout.
Downsides of Benzoyl Peroxide
Irritation: Because it’s an oxidant and produces free radicals, benzoyl peroxide decreases the levels of antioxidant vitamin E in the top layers of skin. This often leads to dryness, redness, peeling and stinging, especially at higher concentrations and in formulations with lots of alcohol. Luckily, 2.5% benzoyl peroxide is as effective as higher concentrations, and causes less irritation. Make sure you moisturise while using BPO!
Bleaching: Peroxides are good at bleaching, and benzoyl peroxide does its chemical family proud by staining your clothes, pillowcases, towels and possibly even your hair white. The solution is to only use white linen when you have benzoyl peroxide on your face and fingers, and to keep your hair off your face.
Allergy (rare): Less than 2% of people are allergic to benzoyl peroxide.
Interaction with tretinoin: Benzoyl peroxide inactivates tretinoin (Retin-A), but the two work well in combination to fight acne. If you want to use the two ingredients together, you can either use BPO in the morning and tretinoin at night, or on alternating days, or use a product that’s specially formulated to keep the tretinoin stable (e.g. Retin-A Micro, which uses microspheres). You could also use a different retinoid, such as adapalene or tazarotene, which don’t interact with BPO.
Not a downside: BP has been found to promote some tumours in mouse studies, but not in most studies. The overall consensus is that it’s unlikely to be an issue.
How do I use benzoyl peroxide for acne?
The best way to use benzoyl peroxide is to cover your clean face with a thin layer of 2.5% or 5% benzoyl peroxide gel, 1-3 times a day. Follow with moisturiser, and use sunscreen during the day. The effects are usually visible within a couple of weeks. After a couple of months, if your acne has reduced enough, you can switch to a rinse-off benzoyl peroxide cleanser to keep the acne at bay.
Product recommendations
I’ve been using benzoyl peroxide since I was a teenager. The two products I’ve been loyally using are:
Acne.org 2.5% Benzoyl Peroxide Treatment ($19.29 USD + shipping for 8 oz) – Fantastic value, with a light, easy-to-apply formula. It also comes in a HUGE 16 oz pump bottle.
Benzac AC 2.5% Gel ($16.95 for 50 g) – Comes in 2.5%, 5% and 10% varieties, and is available in stores in Australia. It contains nifty acrylates copolymer beads containing glycerin, which release glycerin to moisturise your skin while they soak up oil. You can find it almost any pharmacy in Australia.
Proactiv Repairing Treatment ($28.95 AUD for 60 mL) – I used to borrow small amounts of this from my sister for spot treatments. It’s a nice 2.5% benzoyl peroxide lotion, with a slightly sticky texture, but it’s a bit expensive.
Paula’s Choice Clear Regular Strength Daily Skin Clearing Treatment with 2.5% Benzoyl Peroxide
($26 AUD for 67 mL, Amazon link) – I haven’t actually tried this personally, but Paula’s Choice generally make great products. This comes in a 5% version as well.
References
EA Tanghetti & KF Popp, A current review of topical benzoyl peroxide: new perspectives on formulation and utilization, Dermatol Clin 2009, 27, 17-24
OH Mills Jr, AM Kligman, P Pochi & H Comite, Comparing 2.5%, 5%, and 10% benzoyl peroxide on inflammatory acne vulgaris, Int J Dermatol 1986, 25, 664-667
AL Kraus, IC Munro, JC Orr, RL Binder, RA LeBoeuf & GM Williams, Benzoyl peroxide: an integrated human safety assessment for carcinogenicity, Regul Toxicol Pharmacol 1995, 21, 87-107
JM Waller, F Dreher, S Behnam, C Ford, C Lee, T Tiet, GD Weinstein & HI Maibach, ‘Keratolytic’ properties of benzoyl peroxide and retinoic acid resemble salicylic acid in man, Skin Pharmacol Physiol 2006, 19, 283-289
JQ Del Rosso, R Pillai & R Moore, Absence of degradation of tretinoin when benzoyl peroxide is combined with an optimized formulation of tretinoin gel (0.05%) (open access), J Clin Aesthet Dermatol 2010, 3, 26-28
Benzac AC Gel was provided for editorial consideration, which did not affect my opinion. This post also contains affiliate links – if you decide to click through and support Lab Muffin financially, thank you! For more information, see Disclosure Policy.
Very interesting! I also use the Acne.org benzoyl peroxide to manage my acne, and it’s nice to know how it works out. How would you layer other treatment products, like serums, with it? Whenever I try to work another treatment product (like vitamin-C serum) with the benzoyl peroxide, it seems like the acne flares up again.
I haven’t used it all over for a long time – I only get occasional breakouts while using it, so I tend to use it as a spot treatment only. I would probably put on one treatment, wait half an hour then apply the next treatment, or use BP at night and everything else in the morning.
What a helpful post, thanks! And I’m glad I’m doing the right thing because I use Paula’s Choice Clear Daily Skin Clearing Treatment in Extra Strength, which is 5% (I just checked, lol). It works great and I’ve tried so many other treatments previously that have done nothing to clear my breakouts.
Hope it works well for you! Make sure you use lots of moisturiser as well (though I’m sure your skin will let you know if you’re not using enough).
Is it OK to use BP 5% face wash at night and then apply tretonin retina A at night as well?
It should be OK!
Bleaching: My daughter wants to shower at night, then apply benzoyl peroxide to her back. She can wear a white t-shirt to sleep in and use white sheets. But the next day it still bleaches whatever top she wears to school. Is there anything to do other than shower again in the morning?
You could perhaps use a baby wipe or micellar water to wipe down her back in the morning?
Dear Michelle.I hve a problem wth my Face.pimples nd acne so ive brought my First time of using Benzac Ac 5 gel.5% nd it’s my first tym of using it.I feel itchy nd I think My face is reacting. …cse it keeps out all d pimples even those that were hidden.plzz help me. I dnt know whether I shud b patient or stop
Definitely stop! It sounds like an allergic reaction.
Excellent, excellent article! I’ve use BPO for years. It’s the only thing that keeps me clear. When I stop using it, I break out again. The secret to prevent dryness is moisture. After I apply my BPO cream or gel, I let it dry, then glob on the moisturizer (SPF in the a.m.) I find that moisturizers with niacinamide like Olay, or Pond’s Clarant B3 cream work wonders in conjunction with the BPO. Not only does the niacinamide in the cream moisturize, but I feel it also minimizes irritation, which other moisturizers do not. Thanks again for a great article. I’ve used BPO for YEARS. Yeah, I’m in my 60’s and will STILL get acne when I stop using it! It’s great stuff!
Very interesting read. BP has helped my acne immensely!
Do you think using BP and Vit C together is a bad idea? I’ve heard conflicting reports. However, I heard that if you let the BP dry *completely* before your Vit C serum, it shouldn’t affect the efficacy of both or affect the antioxidant benefits of the Vit C.
I’d definitely would be interested in hearing your thoughts, Michelle 🙂
Even if it’s completely dry, I think the BP and vitamin C would still interfere. BP is an oxidant, and vitamin C is an antioxidant, so they oppose each other’s actions. I’d use one in the morning and one at night, with washing in between.
Hi Michelle,
From its downside I think it is little risky for soft skin. You write in your article that it drys skin then I want to know How many years old can use it? Because I also see many short ages have pimples and acne problems with their face. First of all I want to know more advantages of it then I can use this.
I think it’s better for people with oily skin rather than dry.
I love that Benzac AC stuff! It’d be interesting if you did a science-y post pitting Benzoyl Peroxide against Azelaic Acid as an acne/spot treatment. I’ve heard that some people use Azelaic acid as an effective treatment, but I’ve no clue which (out of Benzoyl and Azelaic) is ultimately the better option.
For example, I’ve seen this Ego product at Chemist Warehouse (http://www.chemistwarehouse.com.au/buy/61040/Ego-Azclear-Action-Lotion-25g), but end up grabbing my trusty Benzac AC instead.
Yeah I’m the same – I have Azclear but the texture is pretty unappealing (it’s very sticky and glue-like and rolls off my skin), so I end up going for 10% Benzac AC as a spot treatment. IMO azelaic acid works better as a continuing treatment since it seems to work primarily by increasing skin turnover and reducing inflammation (though it’s antibacterial as well), whereas BP is mostly antibacterial.
Can I use Benzoyl Peroxide with Salicylic acid. I hear contradicting answers.
You can, but it may be too irritating for some people with sensitive skin – I would start slow and ramp up e.g. alternating days first, before trying both on the same day.
I am able to do this with my sensitive skin but I use 2.5% BP leaving it on for a few minutes and then rinsing off before applying a gentle BHA twice a week (I use Cosrx which uses betaine salicylate instead of salicylic acid).
I always thought more people were allergic to BP like I am. My eyes swell shut. Then the skin around them and on my eyelids is red and raw for days after I use it. It worked fantastic for my breakouts… Once I could see again 😉
Oh no, boo! Maybe azelaic acid or tea tree oil will work better for you 🙁
Very interesting article while reading. Great job,It is very useful. Thanks for this helpful article.
Does wash off BP work as effective as topical application of BP? How long do I need to have the wash on?
I don’t think it’ll be as effective, but it will be less irritating if your skin is sensitive.
Oh, I am not familiar on BENZOYL PEROXIDE, but it sounds interesting than the other acne treatment. However, I will do research more about this one before I apply, because there’s a treatment not agreeable to my skin. Moreover, thank you so much for this stuff, Michelle.
You’re welcome 🙂
I’ve been using Paula’s Choice BP 2.5% 2x a day for probably about 6 months now and my skin is looking really good. I’m nervous to cut it down but I really want to be able to use more serums (like vitamin C) more effectively. Do you think I can switch to a BP face wash at this time and would that effect vitamin C? Would I be better moving to 1x a day first? Also wondering if it interacts with glycolic acids at all? I use the Drunk Elephant Night serum.
Just wanted to drop a line saying thank you for your post! It encouraged me to give benzoyl peroxide another try and using the 2.5% as a twice daily wash off treatment has cleared up my skin 3 weeks on!! I’m beyond happy and am recommending it to my friends 🙂
That’s fantastic to hear! 🙂
thanks for sharing this!!
Hi Michelle!
Could I use a vitamin e product in addition to a mosturiser to compensate the oxidation from the BP? Maybe using the BP at night and vitamin e in the morning?
Love from Brazil 😀
That’s a good idea 🙂
Can I use this to spot treat the really deep pimples?
You can, but I’ve personally found that spot treatments don’t work that well for the really large, deep pimples.
Do antioxidant products ‘deactivate’ benzoyl peroxide if used together? e.g. in a high antioxidant serum before or after? I can’t find this information anywhere!
They can cancel each other out. I would try to apply them separately if possible.
Ive tried leaving BP gel on overnight but my face could never tolerate it. Putting moisturizer on to help with dryness and irritation always made things worse. So now I just leave the BP on for 1 hour everyday and then wash it off. This is the only way I can use the product.
Hello, do you wash the BP gel off with a cleanser or just water?
Thank you!
Hi – thank you for this informative post! Do you know if benzoyl peroxide also de-actives retinol/retinal? I wanted to use this as an overnight spot treatment but I use retinal in the evenings.
Thanks
Hey Michelle – do you have any thoughts around BPO causing oxidative stress/free radicals and increasing the rate of premature aging? It’s a great product for me in terms of keep acne at bay, but I’m not sure I want to continue in the long terms if it’s going to have aging effects. Thank you so much!
Acne is probably causing far more oxidative stress, so if it’s keeping it at bay I’d say to keep on using it.
Hi! Great article on BPO. I’m investigating it as a treatment for acne as a chemistry project and was wondering if you could provide more insight into the free radical mechanism. I’m finding conflicting answers on the internet form decomposition forming benzoic acid and benzoyl radicals to a hydrolysis reaction. Ideally I need to draw out the mechanism and explain the process from when it is applied on the fac (chemistry focus rather than biology). If you could help I would be FOREVER grateful.