Polycystic ovary syndrome (PCOS) is the most common endocrine disorder among women of reproductive age and the leading cause of infertility. In this article, we discuss PCOS and the growing body of research supporting ketogenic diets as an effective option to treat this condition and improve overall metabolic health.
What is PCOS?
PCOS is a complex endocrine-metabolic syndrome involving hormonal, metabolic, and reproductive dysfunction. In many women, this includes altered signaling between luteinizing hormone (LH) and follicle-stimulating hormone (FSH). When LH production increases above normal ranges, the body starts producing androgens, like testosterone, which can lead to irregular menses and infertility.
Other signs and symptoms of PCOS include ovarian cysts, excessive body hair, acne, and weight gain, and an increased risk of chronic metabolic diseases like type 2 diabetes and heart disease. Currently, PCOS is estimated to impact approximately 15 percent of women of reproductive age worldwide.
Recently, an international consensus group proposed renaming polycystic ovary syndrome (PCOS) to polyendocrine metabolic ovarian syndrome (PMOS) because the new term better reflects the condition’s complex endocrine and metabolic features and removes the misleading implication that ovarian cysts are the primary characteristic of the condition.
What Causes PCOS?
While the exact cause of PCOS is unknown, researchers believe it’s a combination of genetic predisposition and numerous lifestyle factors. Insulin resistance is commonly seen in women with PCOS, and hyperinsulinemia (chronically high insulin levels) may contribute to hormonal dysfunction by increasing LH production.
Treatment Options for PCOS
In recent years, researchers have increasingly explored dietary and lifestyle interventions for treating PCOS. It remains unclear whether the insulin resistance commonly seen in PCOS is a cause or consequence of the condition. However, emerging research suggests that improving insulin sensitivity and achieving weight loss may significantly improve hormonal imbalances, increase fertility, and reduce miscarriage risk. In addition, improving insulin sensitivity may help reduce excess androgen production and support a healthier balance between LH and FSH. Since improving insulin resistance and body weight seem to play such big factors, the ketogenic diet offers a very promising dietary intervention for PCOS.
Impact of the Ketogenic Diet on PCOS
The ketogenic diet is well known for its potential benefits in weight loss, epilepsy, type 2 diabetes, neurological disorders, and certain cancers. Emerging research also suggests that ketogenic diets may be beneficial for additional conditions, including PCOS. In particular, ketogenic diets have been shown to reduce insulin levels and improve insulin sensitivity, both of which may play important roles in PCOS management.
While clinical research is limited, it is promising and growing:
- A 2005 pilot trial in six obese women diagnosed with PCOS found that limiting carbohydrate intake to 20 grams or less per day for 24 weeks resulted in significant reductions in weight, testosterone, LH/FSH ratio, and fasting insulin levels. In addition, two of the women became pregnant during the study despite previous fertility complications.
- A 2020 trial in overweight women with PCOS found that following a ketogenic diet for 12 weeks led to significant reductions in body weight, visceral fat, glucose, insulin, and triglycerides, in addition to improving reproductive hormone balance.
- In a 2021 randomized trial, 18 women with PCOS, obesity, and liver dysfunction who followed a ketogenic diet for 12 weeks experienced significant improvements in menstrual cycle regularity, blood glucose, body weight, liver function, and liver fat compared to conventional pharmacological treatment.
- A 2023 review of seven trials, including the three above, found that ketogenic diet interventions lasting at least 45 days in women with PCOS significantly improved reproductive hormone levels, reducing LH/FSH ratio and serum free testosterone. Significant weight loss was also consistently observed across all studies.
- In a 2023 retrospective study of 12 overweight women with PCOS who had previously failed to become pregnant with in vitro fertilization (IVF), a ketogenic approach led to significant weight loss, insulin sensitivity, and improvement in metabolic health markers. Moreover, two-thirds of the women became pregnant and successfully gave birth following their second round of IVF after switching to a ketogenic diet.
- A 2024 retrospective study of 30 women with PCOS found that following a ketogenic diet for at least 3 months restored regular menstrual cycles in all participants. Among women trying to conceive, more than half became pregnant during the study period.
Over the past several years, several practitioners have begun prescribing the ketogenic diet as a treatment for PCOS, and many anecdotal success stories have been reported.
The Bottom Line
Although more long-term research is needed, current evidence suggests that ketogenic diets may offer a promising therapeutic option for some women living with PCOS, now increasingly referred to as polyendocrine metabolic ovarian syndrome (PMOS).
Because insulin resistance appears to play a central role in the condition, lifestyle approaches that improve insulin sensitivity – including ketogenic approaches– may help improve metabolic health, hormone balance, fertility, and other symptoms.
