A Dermatologist-Approved Beginner’s Guide To Benzoyl Peroxide For Acne
Everything you need to know about how to use it and what to watch out for
Key takeaways
Benzoyl peroxide is an effective ingredient to treat mild to moderate acne.
When used as a spot treatment, it kills acne-causing bacteria without the risk of antibiotic resistance.
Dryness and mild stinging are common when using benzoyl peroxide, but are usually manageable and temporary.
SPF is a non-negotiable when using benzoyl peroxide.
Disclaimer: I am not a dermatologist. All information in this newsletter is based on scientific research and approved by our in-house board-certified dermatologist. Any advice shouldn’t be treated as prescriptive for your acne, since acne treatment depends on individual context. Kindly consult a dermatologist to understand your skin condition and the severity of your acne before using potent skincare actives.
If you would like to consult our dermatologist, comment or DM us.
If you’ve had acne and been to a dermatologist’s clinic, chances are you’ve been prescribed a benzoyl peroxide spot treatment. I’ve used it too, and it’s become my go-to anti-acne spot treatment - despite some skin drying and stinging that I’ve had to work around. Dermatologists use BPO (AKA Benzoyl peroxide) as the first line of acne treatment, and prefer this over antimicrobial gels or oral antibiotics, but why is that?
In this Substack, we’re going to talk about why dermatologists prefer benzoyl peroxide and what you should and should not be doing while using this potent skincare active.
Note: We will be using BPO and Benzoyl peroxide interchangeably in this article
P.S - You can find benzoyl peroxide in face cleansers too, but in this issue, we will be focusing on BPO spot treatment. This is largely because BPO can be too drying when used over the whole face and has limited benefit in a rinse-off format (like in a cleanser) . The targeted leave-on application, like in a spot treatment, is better suited for acne care.
What is Benzoyl Peroxide?
Benzoyl peroxide is an effective, safe and widely studied treatment for acne (acne vulgaris); commonly used to treat mild and moderate acne. It is known for its antimicrobial action against P. acnes (or Cutibacterium acnes), which is the acne-causing bacterium.
In simpler terms, it helps kill acne-causing bacteria, helps shrink the acne lesion and resolves it faster when used correctly.
Benzoyl Peroxide doesn’t contribute to antibiotic resistance: Unlike topical antibacterial gels like clindamycin (an antibiotic), benzoyl peroxide doesn’t pose a risk of antibiotic resistance since it’s not an antibiotic. This makes it a more favourable first-line treatment option.
How does it work?
Here’s what happens when you apply a benzoyl peroxide spot treatment:
It gets broken down into free oxygen radicals in your skin, which kill acne-causing bacteria. Think of them as tiny scissors cutting through paper — in this case, they cut through the bacterial cell membrane (their outer protective layer), in turn killing them.
Benzoyl peroxide also breaks down keratin. This helps unclog pores, removes dead skin cells and helps prevent acne from progressing.
At the same time, it helps reduce inflammation and redness, which is why your painful red pimples visibly appear to calm down.
➡️ Benzoyl peroxide has a broad-spectrum antimicrobial activity that can last for 48 hours, even when the conditions for bacterial growth are favourable [Source: ScienceDirect]
Are there any side effects to this derm-approved spot treatment?
Benzoyl peroxide, like most potent skincare actives, comes with some side effects - most of which are temporary.
You might experience some drying of the skin at the site of application.
You might experience a mild stinging sensation or itching post-application, which gradually subsides.
It increases the skin’s sensitivity to UV light, which is why daily sunscreen use is critical.
This is why patch testing becomes critical before using benzoyl peroxide. If you experience severe itching or burning, or redness or dryness that does not improve in a few days, you should discontinue use immediately and consult your dermatologist.
What you should and shouldn’t be doing when using Benzoyl Peroxide
The efficacy of skincare actives depends not only on the formulation but also on how they’re used and tolerated over time. To benefit from a BPO spot treatment without harming your skin, here’s a derm-approved checklist.
Do’s:
Given its photosensitive nature, BPO is best used at night. Use SPF 50 daily while using a BPO spot treatment to protect your skin from sun damage (even if you’re only going out for a short while, or if you’re home but near a lot of light or windows).
Use a non-comedogenic moisturiser after applying BPO to support the skin barrier and prevent drying.
Only apply the spot treatment after cleansing your face.
More is not better. Use just enough product to cover the acne lesion - about the size of 1-2 rice grains.
Don’ts:
Do not apply it to open, broken or bleeding acne lesions.
Do not apply it all over your face - it is meant for targeted use only.
Do not use incompatible or other harsh actives while using it, like Vitamin C, retinoids, or exfoliants.
Who can use Benzoyl Peroxide? — Most children and adults above 12 years of age can use BPO. If you’re pregnant or breastfeeding, or new to benzoyl peroxide, please consult a dermatologist before use. Do not use it if you are allergic to benzoyl peroxide.
There’s a reason why dermatologists like Benzoyl Peroxide after all
Benzoyl peroxide gets the job done and is more potent than salicylic acid, azelaic acid, or sulfur spot treatments when dealing with moderate acne. It is faster-acting than retinoids and doesn’t come with the risk of antibiotic resistance like antimicrobials.
When used correctly and in the right concentration, it serves as a safe + effective anti-acne treatment. Even in our trial cohort, users saw positive changes w.r.t to their acne with benzoyl peroxide.
It won’t necessarily ‘cure’ your acne because to do that, you need to address the root cause. Benzoyl peroxide helps tackle active acne lesions, reduce inflammation, and fight acne-causing bacteria.
To truly tackle acne, it needs to be addressed at the root.
So far, we’ve helped 30+ people get rid of their stubborn acne in under 5 weeks through our Cohort 1.0 by following an inside-out approach.
✅ We’ve now opened 10 more slots in our second cohort!
New BPO user and this is so helpful
So informative! I would also recommend being super careful with clothes and linens while using bp. A lot of my nice clothes from my earlier years are bleached from say a glob of bp that I dropped on the counter.
Also I have sometimes applied too much BP and burnt my skin 😂 it was fine, healed eventually but I remember canceling outings so that I could stay home in embarrassment