A Chemists’ Introduction to Acne

Most of us have dealt with acne in our high school years and then there’s some of us that will be dealing with it way into our adult years (*Victoria is one of them). So let’s go through some acne basics so we can get comfortable with these event-ruining red bumps of annoyance and make our peace with it!

Acne Culprits: Sebaceous Glands + P. Acnes Bacteria

Acne can come at you from all angles — stress, inflammation, hormones, etc. but the root of the problem starts in the sebaceous gland.

Sebaceous glands have an important role in maintaining skin health. They secrete antimicrobial lipids, upregulate antioxidants, maintain pro and anti-inflammatory properties, and secrete sebum. However, sebaceous glands possess all the right settings for acne growth. The glands’ proinflammatory lipids can aggravate the follicle resulting in unwanted lesions. Additionally, the class of hormones, androgen, can cause sebaceous glands to send their cell growth and sebum production into hyperdrive, and sebum happens to be the primary food for Propionibacterium acnes (P. acnes).

These rod-shaped bacteria prefer to live in an anaerobic (no oxygen) environment, and set up shop deep in our pores and hair follicles, feeding on the secreted sebum. Before freaking out, know that most of us have p. acnes happily living in our skin as part of our normal skin microbiome (normal microbes community) without causing pimples. But when P. acnes growth gets out of hand, a series of unfortunate events happen. First, a comedone occurs, then the buildup of the bacteria secretion leads to inflammation. Eventually the follicle ruptures, then voila — acne is born.

Antibiotics might seem like the next logical course of action, but studies have suggested long term antibiotics is not ideal due to acne resistant strains of P. acnes. Yikes!

Chemists’ General Acne Fighting Skincare Routine Guidelines

  1. Sunscreen. As much as you may hiss and boo at it, if you’re using any of the classic acne bashing ingredients you still need to protect your delicate skin from the sun while it’s under treatment.

  2. Your face isn’t that dirty! There’s no need to wash it 4 times a day, and washing it too often can make things worse.

  3. Refrain from nuking your skin. The challenge with acne treatments is that they are strong. Many of these treatments contain additional ingredients like witch hazel, alcohol, clays, and silica to further dry out the acne lesion. While great in attacking acne, skin does end up suffering too. Additionally, in the midst of a breakout, it’s easy to want to nuke your skin by layering every single acne bashing product you can get your hands on. Try your hardest to refrain. What’s worse than regular acne? Inflamed acne. And with inflamed acne, any of those acne-fighting ingredients will just anger it even more. Keep OTC acne treatments to 1-2 products maximum.

  4. Still use a light moisturizer. It’s easy to want to leave those lesions alone to shrivel and dehydrate but the rest of your skin still needs to stay nice and healthy.

  5. Hang in there! It’s just a patience game after that.

Acne-Fighting Ingredients Overview

Benzoyl Peroxide (BPO) – BPO is the original gold standard of OTC acne ingredients because it’s an antimicrobial that can minimize bacteria resistance and even help manage sebum production. You’ll often find BPO products ranging between 1-10%. There are plenty of clinicals showing the efficacy of this ingredient’s acne-fighting prowess, but beware! It’s very potent. We recommend trying the 1% before going straight for the 10%.

Salicylic Acid (SA): Consider this as the gentle alternative to BPO, you can find SA products ranging between 0.5% to 2%. Unlike AHAs, salicylic acid is oil-soluble, which means that it can penetrate deep into the pores.

Adapalene: Hallelujah, this synthetic retinoid became OTC. Adapalene has shown great potential as both an acne and wrinkle fighter. It’s a potent keratolytic agent that also has been found to have anti-inflammatory properties. Win-win. Additionally, it has been compared to BPO and retinoic acid in clinical tests. 0.1% adapalene was found to be comparable to 5% BPO and 0.025% retinoic acid. You’ll find adapalene sold at the 0.1% level. We think this is the right amount to start at with minimal irritation. For stronger doses seek out your derm.

Tretinoin (Retin-A): Being the most potent of retinoids, in the US this ingredient will be prescription only. Ranging from 0.01 to 0.1%, this is a tried and true ingredient that has shown great efficacy against acne and wrinkles. Beware, as you need to go at it slow and steady to avoid intense peeling. Also if you’re using BPO, let your doctor know as these two don’t play well together as BPO causes tretinoin to degrade. As all those commercials say: *consult with your doctor to see if Retin-A is right for you.


  • Acne can stem from many issues: bacteria overgrowth, sebaceous gland issues, inflammation, lifestyle stressors. It comes from all angles.
  • BPO is the golden OTC ingredient, but there are alternatives to this harsh active. Avoid using this with tretinoin.
  • Consider adapalene. It’s comparable to a weak retinoic acid and you don’t need a prescription for it.
  • Pamper your skin while dealing with a breakout. It’s already under attack.
  • If using any of these ingredients, you need sunscreen.
  • Patience, patience, patience!

We only covered the surface of the acne topic (hah! Pun intended). More to follow on acne scarring, cystic acne, and the microbiome. Stay tuned!

Sources and further reading

Great read on the relationship between P. acnes and skin conditions

A great overview on adapalene for acne

Inflammation and acne

BPO Formulations

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