Main Causes of Acne

Constantly questioning what causes your acne - read this article to find out.

What causes my acne? It’s the big question that plagues the mind of so many men and women. Even health professionals and researchers have struggled with this question, with new theories and evidence constantly emerging. Acne is complex, and its formation has been linked to four key interrelated events in scientific research:

  1. Overproduction of SebumExcessive production of the skins oil (sebum) by the sebaceous glands in the follicle.
  2. Follicular hyperkeratinization (or hyperkeratosis)an overproduction of the skin’s protein, keratin, which causes the skin cells to stick to each other. The skin cells then build up inside the pore and can’t shed off on the outer surface of the skin. So you’ve got more sticky skin cells not going anywhere and clogging inside the pore.
  3. Bacterial Colonisation – overgrowth of acne-causing bacteria known as Cutibacteruim acnes (formerly Propionibacterium acnes or P.acnes) within the follicle. This bacteria has been shown to increase inflammation and sebum production at the acne site and alters the skin’s microbiome, limiting the growth of good bacteria.
  4. Inflammation at the follicle site

If went straight over your head, in a nutshell: the increase in oil mixes with an excess of skin cells which clogs the follicle and creates an ideal environment for the rapid growth of C. acnes. This then triggers an inflammatory response inside the pore. The resulting interplay of these four results in the formation of acne and the progression into cystic inflamed acne.

Process of acne formation

Acne Causes

The combination of the four key acne-forming events above are triggered by things internally and externally which we will classify as the main causes of acne. These are:

  • Genetics
  • Hormones
  • Pore Clogging Ingredients
  • Diet
  • Gut Health


You heard it, genetics have a role in the formation of acne (thanks mum and dad, or was it grandad?). Genetics play a large role in determining the individual’s severity and susceptibility of acne. There is no specific “acne gene” per say, but there are particular genetic markers that if expressed, can contribute to the formation of acne.

A 2018 genome analysis identified 15 genetic locations that have the potential to cause 20 processes associated with the formation of acne. For example, there are genes involved in the overproduction of sebum, or cause hyperkeratosis, or that increase the inflammatory response in acne lesions. And when certain gene combinations are expressed together it can cause acne and influence how severe your acne might be.

If you’re thinking: well, it’s in my genes I can’t do anything about it, then I have some good news. Just because we’ve got a genetic predisposition to acne, doesn’t mean that all hope is lost. Genes can be switched on and off and are influenced by external and internal factors that are in our control such as diet, hormones, environment and skin care. You actually have a lot more power in how to manage your genetic manifestation of acne and keep your skin looking clear (so you’ll want to keep reading).


An imbalance of hormones has a major role in the formation of acne. It’s fairly a detailed conversation, so here’s the express version. Our male hormones, known as androgens, are the number one hormonal culprit: testosterone and its supercharged form, dihydrotestosterone. These androgens cause a significant increase in sebum production in the follicle, which as we now know, is one of the main factors to acne formation.

The production of testosterone is also influenced by other hormones such as estrogen and progesterone which is why an imbalance of these hormones can also trigger an increase in acne.

The delicate balance of hormones is influenced by a multitude of factors such as toxins from the environment, certain supplements (such as vitamin D, B12 and zinc) and diet. For a detailed explanation of what causes hormonal acne, stop in and have a read here.

Stress, or cortisol to be specific, is another hormone that can impact our skin. It does this by quieting our immune system, disrupting our gut bacteria and directly causing skin inflammation.

Pore Clogging Ingredients

There are SO many hidden pore cloggers in our products. And I’m not just talking about skin care. Pore cloggers are in makeup, shampoo and conditioner, soaps, fabric softers and detergents. I was honestly shocked to find out that so many of my products that I thought were clean and natural had some of the worst pore clogging ingredients in them. Yes, even those expensive organic, non-toxic, natural moisturisers and serums have some nasty pore cloggers in them such as shea butter, algae and coconut oil.

Even if a product is natural and organic, if it’s got pore clogging ingredients, it just means it’s going to give you natural pimples.

Essentially these products are, on a molecular level, shaped differently or too large for our skin’s pore which clogs the follicle. This leads to the cascade of events that can give rise to the formation of acne – especially for those who are genetically acne prone. (That’s why Jane can cleanse with coconut oil but you’re breaking out like there’s no tomorrow).

FYI you can check all your products against this list to see if there’s any hidden pore cloggers. One of the best things you can do for your skin!


If someone has ever said to you that diet does not cause acne – they are wrong. Dead wrong. Unfortunately, there are multiple acne-triggering foods that can be contributing to your breakouts. Briefly, the big ones are: dairy, sugar, gluten and eggs.

  • Dairy: I hate to say it, but dairy and acne are not like Chandler and Joey – they’re just not friends. And that’s ALL forms of dairy: that baked brie on last weekend’s cheese platter, your latte on skim milk, the whey protein in your smoothie, or the yoghurt and muesli for breakfast. Dairy triggers Insulin-Like Growth Factor (IGF-1) hormones causing an increase in testosterone and thus acne. It acts so fast that generally you can see a breakout within 24-48 hours of consuming dairy.
  • Sugar: Sugar and high GI foods like white breads, pastas and white rice, all trigger a spike in your blood sugar and simultaneously cause a spike in insulin. Similar to dairy, this then triggers the release of Insulin-Like Growth Factor (IGF-1) leading to acne. Tip: when you are consuming sugar or higher GI foods, it’s best to eat them when there is a balance of protein and fats included to stabilise the blood sugar increase. Following an anti-inflammatory, minimally processed, low-GI diet is key to promote blood sugar stabilisation and yep: clear skin
  • Gluten: Gluten causes tiny little holes in the lining of the gut wall (known as intestinal permeability or leaky gut) which can result in food and other larger particles seeping through into your bloodstream causing an inflammatory response. Inflammation in your body, can then manifest as inflammation on your skin. It’s all linked!
  • Eggs:  Eggs are a nutritional powerhouse but if you are consuming eggs on a daily basis, it might be a surprising ingredient to your acne problems. Eggs have a high amount of progesterone as well as a difficult to digest protein called albumin which can clog up the lymphatic system. The lymphatic system is a major detox pathway so when it’s not working effectively, it can cause breakouts around the perimeter of your face, jaw and down the neck. Similarly, eggs are a common allergen so if you are intolerant to eggs it can cause inflammation in the body and skin inflammation. Try cutting out eggs for a few weeks then reintroducing them to see where your egg tolerance lies.

Other dietary things to watch out for are soy, caffeine and alcohol which all can have links to forming acne. However, it’s about your individual tolerance for these foods – every person is unique.

Gut Health

This topic often gets overlooked in the conventional acne advice space, but the health of your gut is a massive piece in the complex jigsaw of acne. You can fix everything else, but if you haven’t cleaned up the function of your gut then you’re just going to keep running an uphill marathon.

The health of your skin can be a direct reflection of the health of your gut. If you’ve got a poor functioning gut, it’s going to manifest on your skin – especially if you’re more acne prone. This is through what’s known as the gut-skin axis. Take it from me, my skin dramatically improved after I cleaned up all the shit that was happening in my gut (quite literally).

The health of your gut not only includes your digestion – how effectively you absorb the food you consume – but also involves the trillions of bacteria in your gut and the gut lining that houses them all. Studies have shown that people with acne have a decreased diversity of gut bacteria and increased intestinal permeability (or leaky gut). Studies are also demonstrating the link between gut inflammation and skin inflammation.

Generally speaking, the best things we can do to support our gut health (and our skin) is to consume a nutrient-dense, wholefood diet with an abundance of plants, fibre-rich fruits and vegetables, probiotic and prebiotic rich foods, as well as supplementing with a high quality broad-spectrum probiotic or spore based probiotic.

So there you have it. Acne is complex with multiple causes so it’s never just going to be a one hit wonder to cure (unlike that band who sang “Who Let the Dogs Out” in 2000). It takes a multifactorial approach to treat acne.

Never feel disheartened on your acne journey – you are empowering yourself with the knowledge and tools to help solve the puzzle from the inside out. And I’m so proud of you!

If you’re wanting more information about each topic, I deep dive into each of these triggers in other blog posts so you don’t have to prowl all over the internet for it.

For now, I’d love to know your thoughts: comment below, send me an email or DM me over on social if you’ve got any specific questions. I always love hearing from you!

Sending love always,


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Lee, Y. B., Byun, E. J., & Kim, H. S. (2019). Potential Role of the Microbiome in Acne: A Comprehensive Review. Journal of clinical medicine8(7), 987. https://doi.org/10.3390/jcm8070987

Platsidaki, E., & Dessinioti, C. (2018). Recent advances in understanding Propionibacterium acnes ( Cutibacterium acnes) in acne. F1000Research7, F1000 Faculty Rev-1953. https://doi.org/10.12688/f1000research.15659.1

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