5 underlying causes of adult acne: a functional medicine approach to breakouts

Hormonal acne can have a range of causes. Taking a functional medicine approach can help you heal your acne from the inside out.

During any life stage, acne can be a devastating condition to deal with. From personal experience, I understand that the ramifications of acne can extend far beyond physical symptoms. Over the years, I have worked tirelessly to address my PCOS, and one of its main symptoms, acne, through diet and lifestyle changes along with nutritional supplementation. Today, I am honored to share my knowledge and experience with other women who are experiencing similar health issues. 

An extensive number of studies now confirm that acne is a manifestation of several underlying root causes such as hormonal imbalances, gut inflammation, food sensitivities, and  nutritional deficiencies. In this post, I explain these underlying root causes in-depth as I believe having this information is empowering and allows you to take actionable steps towards addressing your acne.

Elevated Testosterone  

One of the hormones that is most strongly associated with acne is testosterone. Women with elevated testosterone typically have a higher conversion rate to dihydrotestosterone (DHT), a more potent androgen that will ultimately cause increased sebum production, clogged pores, and acne. This is the same hormone that is also responsible for male pattern hair loss in women and hirsutism, a condition by which hair grows on parts of the body where hair is normally absent or minimal.  

Two reasons why women may have elevated testosterone include estrogen dominance and polycystic ovarian syndrome (PCOS):  

  • Estrogen dominance occurs when there is too much estrogen compared to normal progesterone levels, or normal estrogen relative to low progesterone levels. Progesterone has an inhibitory effect on DHT, but when estrogen is more dominant, progesterone does not have the ability to block DHT. In turn, DHT remains unopposed and has the ability to exert a greater effect on the skin (1). When a woman has estrogen dominance, her acne is likely to be most pronounced during the luteal or second phase of her menstrual cycle. It is during the second phase of the menstrual cycle that progesterone should be the dominant hormone, but due to the increased levels of estrogen blocking progesterone, DHT will continue to promote acne. Unfortunately, there are many causes for estrogen dominance. Some of those reasons include pesticides and herbicides found in inorganic produce, environmental toxins found in tap water, BPA found plastics, and chronic stress. Symptoms of estrogen dominance are also diverse and vary in severity. Common symptoms include fibroids, breast tenderness, irregular menstruation, ovarian cysts, PMS symptoms, and of course, acne.  
  • PCOS, short for polycystic ovarian syndrome, is another common reason for elevated testosterone in women. For the majority of women with this condition, insulin resistance, blood sugar dysregulation, and chronic inflammation are the underlying causative factors. This insulin surge goes on to signal the ovaries to produce excess testosterone. This additional testosterone then signals our skin cells to increase oil production, which in turn causes acne (2).

Elevated Cortisol  

Every time we encounter a stressful event, our brain releases a hormone called corticotropin-releasing hormone (CRH), a hormone that signals our adrenals to release cortisol to combat the stress we are experiencing. There is actually a CRH receptor on every skin cell. So when we experience stress, CRH binds to its receptor on the skin cell, promotes oil production, and ultimately, contributes to the development of acne (3).  

In fact, a 2017 study showed that female medical students exhibited an increase in acne severity during times of heightened stress. The study concluded that stress positively correlates with acne (4). Additionally, it is not only psychological stress that can cause acne, but also physical stress such as environmental toxins, cigarette smoke, and UV radiation that can also contribute to a stress response, and in turn, cause acne and other skin ailments (5).  

Furthermore, acne can also be driven by another stress hormone called dehydroepiandrosterone sulfate (DHEA-S). This hormone is produced by the adrenal gland and acts as an androgen in the body, similar to testosterone and DHT. In excess, DHEA-S can lead to a condition known as Adrenal PCOS, a type of PCOS that is not as common, but is still responsible for acne, hair growth in unwanted places, and chronic inflammation in the body (6).  

Gut Imbalances  

Research on the microbiome has exploded over the last several years. It is becoming increasingly clear that our microbiome plays a strong role in the management of hormones, specifically estrogens. In fact, specific bacteria in our gut can actually secrete an enzyme called beta-glucuronidase that causes estrogen to recirculate in the body instead of clearing out via elimination. When a state of microbial imbalance is present, select bacteria can produce more of this enzyme. If more beta-glucuronidase is present in the gut, less estrogen will be excreted from the body. This recirculating estrogen will go on to bind to estrogen receptors and have a more pronounced estrogenic effect on the body (7). In other words, a microbiome imbalance can create a state of estrogen dominance, which in turn can promote more acne.  

Food Sensitivities  

The three most common dietary triggers for acne include sugar, dairy, and gluten. When I first begin working with a client who presents with acne, I strongly advise removing these foods from their diet and see what impact this has on their acne.

Sugar is a known culprit of inflammation and insulin resistance. This is the same underlying mechanism that promotes acne. Over time, this excess insulin can signal the ovaries to produce more testosterone, one of the main hormones responsible for the development of acne. In fact, a 2017 study found that participants with moderate to severe acne consumed more carbohydrates and had greater insulin resistance than participants without acne (8). Another study completed in 2019 found that daily soda consumption significantly increased the risk of moderate to severe acne in adolescents, especially if the sugar intake exceeded 100g per day (9). Therefore, in addition to limiting your intake of refined sugar, it is important to limit refined carbohydrates as well. This includes your intake of processed foods, white flours, pastries, cereals, etc.

Dairy is another significant contributor to acne, especially cystic acne. Dairy products contain a hormone called insulin-like growth factor-1 (IGF-1). This hormone is found in milk derived from all species including cow, sheep, and goat. The IGF-1 hormone can mimic our own endogenous insulin, and can therefore signal our ovaries to produce testosterone. This excess testosterone then promotes the development of acne. A 2018 meta-analysis evaluating the impact of dairy products on 78,529 individuals found that any dairy, such as milk, yogourt, and cheese was associated with an increased risk for acne (10).

Another strong culprit for acne is gluten. While there are no direct studies evaluating the impact of gluten on the development of acne, anecdotally speaking, I have witnessed my clients experience an improvement in their acne after beginning a strict gluten-free diet. In addition, numerous studies have now described the inflammatory effect of gluten on the skin. In fact, gluten sensitivity is associated with skin conditions such as dermatitis herpetiformis, psoriasis, and eczema (11). It is believed that this same underlying inflammatory mechanism is the causative factor for acne in individuals presenting with a gluten sensitivity.  

Nutritional Deficiencies  

Nutrients that are vital to skin health include vitamin A, vitamin D, omega-3 essential fatty acids, and zinc. A deficiency in any or all of these nutrients can promote the pathogenesis of acne (12)(13).  

  • Vitamin A is critical to skin regeneration. Quality sources of vitamin A include egg yolks, cod liver oil, and orange colored vegetables such as sweet potato, pumpkin, and squashes.  
  • Vitamin D plays an important role in taming inflammation. Since acne has an inflammatory component, vitamin D is crucial for reducing this inflammation. Vitamin D is most readily absorbed through the skin. It is recommended to spend at least 15-30 minutes outside, though factors such as latitude and skin tone can impact vitamin D absorption.  
  • Omega-3 essential fatty acids help to maintain cell membrane elasticity and structural integrity. Our skin’s structural integrity is dependent on the structural integrity of its cells. Therefore, it is important to consume high quality omega-3 fatty acids regularly. Examples include walnuts, hemp seeds, chia seeds, and wild-caught seafood such as salmon, sardines, mackerel, and anchovies.  Zinc is an essential mineral that is critical for maintaining skin health. It protects against oxidative damage, and also increases the activity of vitamin A, and therefore, skin regeneration.
  • Zinc is found most abundantly in oysters, clams, red meat, and poultry. Plant sources of zinc are available but are not readily bioavailable compared to animal sources of zinc.  

How To Combat Acne From A Functional Medicine Perspective  

Now that we’ve outlined the most common underlying root causes of acne, I want to share some of the initial healing steps you can take to overcoming bothersome breakouts:  

  • Begin with an elimination diet. I recommend my clients eliminate sugar, dairy, and gluten for a minimum of 30 days. If you notice a significant improvement, you can continue with this new dietary approach, or reintroduce each of these categories back into your diet one at a time to determine which food group is causing the acne.  
  • Balance your blood sugar by eating a primarily whole foods anti-inflammatory diet. This is essentially a paleo approach that includes tons of unprocessed fresh foods such as fruits and vegetables, healthy fats, and palm sized servings of wild-caught, pasture-raised, and grass-fed meats. This protein, fat, and fiber combination is going to help stabilize blood sugar levels and eliminate the insulin surge that would promote the release of more testosterone from the ovaries. Additionally, eating this varied paleo diet will help to ensure you are getting all the nutrients that are critical for maintaining skin health.  
  • Add fermented foods such as sauerkraut, kimchi, and coconut yogurt into your diet. Remember gut imbalances can promote estrogen dominance, and ultimately, acne. This extra dose of beneficial flora is therefore incredibly beneficial to skin health.  
  • Consciously de-stress. Take time each day to pause, reflect, deep breath, and mediate. These exercises are intended to bring us back to center and lessen the production of CRH. Remember when our stress levels increase, the amount of CRH circulating in the bloodstream will also increase. Reducing CRH levels through conscious stress reducing techniques can, in turn, reduce stress induced acne. Furthermore, the best way to combat acne driven by adrenal PCOS is to keep stress levels down as much as possible.  
  • Reduce xenoestrogen exposure. Xenoestrogens are endocrine disrupting chemicals that mimic the estrogen hormone. Unfortunately, our bodies cannot distinguish between our endogenous estrogen hormone and xenoestrogens. Therefore, xenoestrogens can promote an estrogenic effect on the body and create a state of estrogen dominance. Xenoestrogens are found in plastics such as plastic storage containers, pesticides and herbicides in food, and household chemicals. It is best to minimize exposure to these chemicals in order to reduce the estrogen load on the body.  

When It’s Time To Consult With A Functional Medicine Practitioner  

If you don’t see improvements in your acne after implementing these initial steps, I encourage you to work with a practitioner that specializes in a functional medicine approach to acne. You may require in-depth functional testing that assesses your sex and adrenal hormones as well as your microbiome status. With this testing data, your practitioner can then help you decode your symptoms from a whole body systems perspective, and offer a comprehensive diet, supplement, and lifestyle program to help you finally put your acne symptoms into remission.


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Dr. Pooja Mahtani

MS, CNS, LDN, PharmD

Dr. Pooja Mahtani is the founder of Pooja Mahtani Wellness, a virtual functional nutrition practice that specializes in gut, immune, and hormonal health. Dr. Mahtani is a Board Certified Nutrition Specialist® and Licensed Dietitian Nutritionist. She also holds a Doctorate in Pharmacy and Master’s in Human Nutrition along with extensive training in functional nutrition from the Institute for Functional Medicine.