Metformin for Acne

Today, I'll share some fascinating studies emerging that demonstrate metformin's ability to clear acne. It makes sense to me, as excess sugar and carbohydrate consumption can induce insulin resistance and subsequently an imbalance of hormones and greater risk of bacterial infection. Recently speaking at the Australian Doctor's Dermatology Academy in Sydney, Professor Dedee Murrell, head of dermatology at St. George Hospital, said: "There is increasing evidence to suggest that insulin resistance can be associated with acne. Insulin resistance contributes to hyperandrogenism and increased sebum production."

The 2019 study Efficacy of Metformin in the Treatment of Acne in Women with Polycystic Ovarian Syndrome (PCOS): A Newer Approach to Acne Therapy found that "metformin treatment significantly reduced acne severity in patients with PCOS."

A recent paper Metformin - For the Dermatologist cited a 2007 study out of Germany that found all 188 female patients with PCOS treated with metformin ranging from 500mg-1g twice daily for six months had a reduction in their acne, regardless if they were lean, overweight or obese. There was also a favorable outcome with respect to menstrual irregularities, insulin resistance and serum testosterone levels.

The 2021 study Prevalence, Clinical and Biochemical Characteristics of Female Acne Patients with Insulin Resistance looked at 524 women averaging 23 years old with mild, moderate and severe acne and healthy controls the same age. Women with acne had a significantly higher prevalence of insulin resistance than healthy controls, particularly those with moderate and severe acne. Insulin resistance was determined by HOMA-IR values. Check out my article about the HOMA-IR test for more details. It's essentially a test to determine the presence of insulin resistance in the body.

Metformin is not just getting positive results with acne in women. The 2016 study Low Glycemic Diet and Metformin Therapy: A New Approach in Male Subjects with Acne Resistant to Common Treatments found that the group that received metformin plus a hypocaloric diet for six months had a statistically significant improvement in their acne compared to the group that did not undergo a diet change or receive metformin. They concluded that "our study reveals the importance of diet and insulin resistance in acne pathogenesis, and underlies the possible use of metformin and diet as possible adjuvant therapy for male patients with acne."

The April 2016 study Insulin Resistance and Metabolic Syndrome in Young Men with Acne assessed the prevalence of metabolic syndrome and insulin resistance in male patients 20 years or older with acne. The researchers concluded that post-adolescent male patients with acne more commonly have insulin resistance and may develop hyperinsulinemia or type 2 diabetes in the future.

The 2012 study Insulin Resistance and Acne: A New Risk Factor for Men? found a metabolic imbalance in young males affected with acne. "Insulin resistance seems to play the main role for the development of acne in these subjects," the researchers concluded. "Insulin resistance could represent an effective target for therapy in male acne."

A couple more: 

The 2015 study Insulin Resistance in Severe Acne Vulgaris found that fasting blood glucose levels were not different in patients with acne versus without, however the fasting insulin levels were significantly higher in patients with acne versus those without acne.

The 2019 study Insulin Resistance in Adult Acne concluded that: "in our study, we found the association of insulin resistance and acne in adults to be statistically significant even in the absence of PCOS, suggesting a direct relationship of insulin resistance with acne in adults." 

High sugar consumption also leads to immunosuppression and proliferation of Demodex mites. Research has been highlighting the link between Demodex mite infestation and both acne and rosacea. The 2022 case report Demodicosis Imitating Acne Vulgaris: A Case Report described a patient "first diagnosed as acne vulgaris and treated with doxycycline for 2 weeks, but the clinical symptoms did not show any signs of improvement. After reassessment based on clinical presentation and laboratory examination that found multiple Demodex mites from pustules and rash on both cheeks, the patient was diagnosed with folliculitis-like type demodicosis." The patient had a complete disappearance of symptoms with oral ivermectin and metronidazole.  

The 2020 study Demodex folliculorum infestations in common facial dermatoses: acne vulgaris, rosacea, seborrheic dermatitis determined: "The findings of the present study emphasize that acne vulgaris, rosacea and seborrheic dermatitis are significantly associated with Demodex infestation. Standardized skin surface biopsy is a practical tool in the determination of Demodex infestation."