A new review looked at eight studies about how a ketogenic diet (a diet very low in carbs and high in fat) might help women with PCOS, a common hormone condition. Women who tried different versions of the keto diet lost weight and showed improvements in blood sugar control, hormone levels, and menstrual cycles. While these results are encouraging, researchers say more long-term studies are needed to understand if these benefits last over time and who would benefit most from this approach.

The Quick Take

  • What they studied: Whether eating a ketogenic diet (very low carb, high fat) could help improve symptoms and blood test results in women with PCOS (polycystic ovary syndrome)
  • Who participated: Eight different research studies involving women diagnosed with PCOS who tried various versions of a ketogenic diet. The exact total number of women studied wasn’t specified in this review
  • Key finding: Women with PCOS who followed a ketogenic diet experienced weight loss and improvements in multiple health markers including hormone levels, blood sugar control, insulin levels, and menstrual regularity
  • What it means for you: If you have PCOS, a ketogenic diet may help improve your symptoms and blood work results in the short term. However, this is still an emerging area, and you should discuss any major diet changes with your doctor to make sure it’s right for your specific situation

The Research Details

This was a scoping review, which means researchers searched through scientific databases (CINAHL, PubMed, and Google Scholar) to find all studies published between 2019 and 2025 that tested whether a ketogenic diet helped women with PCOS. They found eight studies that met their criteria and analyzed what each one found.

The studies looked at different versions of the ketogenic diet: some were very low-calorie versions, some were regular low-calorie versions, some were classic ketogenic diets, and one was a Mediterranean-style ketogenic diet. This variety helps show whether the benefits come from the ketogenic approach itself or depend on how strictly people follow it.

The researchers looked at whether the diet improved specific blood test results (like hormone levels and blood sugar) and whether women experienced better menstrual cycles and fertility outcomes.

A scoping review is useful because it gives a broad overview of what research exists on a topic. Instead of doing one big study, researchers looked at multiple smaller studies to see if there’s a pattern. This helps doctors and patients understand what evidence exists and where more research is needed. For PCOS, this matters because it’s a common condition affecting many women, and finding safe, non-medication treatments is important.

This review has some important limitations to understand: First, it only looked at studies from 2019-2025, so it might have missed older research. Second, the eight studies included were likely different from each other in how they were designed and who participated, which makes it harder to draw firm conclusions. Third, the review doesn’t tell us the total number of women studied or how long most of these studies lasted. Finally, scoping reviews are meant to give an overview rather than provide definitive answers, so these findings suggest promise but aren’t conclusive proof.

What the Results Show

All eight studies showed that women with PCOS who followed a ketogenic diet lost weight, regardless of which version of the diet they used. Beyond weight loss, the research found improvements in several important blood markers: androgen levels (male hormones that are often too high in PCOS) decreased, lipid levels (cholesterol and triglycerides) improved, and blood sugar control got better.

Women also showed improvements in insulin levels and insulin resistance (measured by something called HOMA-IR), which is important because insulin problems are a major part of PCOS. The ratio of two hormones called LH and FSH improved, and other hormone markers like DHEAS, SHBG, AFC, and AMH showed positive changes.

Beyond blood work, women reported real-life improvements: their menstrual cycles became more regular, some experienced improved fertility, and there were fewer cases of a condition called OHSS (ovarian hyperstimulation syndrome) that can occur during fertility treatments.

The studies tested different versions of the ketogenic diet, and all versions showed benefits. This suggests that the general approach of eating very low carbohydrates and high fat may be what matters, rather than one specific version being clearly better than others. The Mediterranean-style ketogenic diet (called KEMEPHY) was interesting because it combined keto principles with Mediterranean diet elements, showing that you might not need to follow the strictest version to see benefits.

Previous research has suggested that diet changes can help PCOS symptoms, but this review specifically focused on ketogenic diets, which is a newer area of study. The findings align with what we know about how low-carb diets can improve insulin resistance and hormone balance. However, most previous research on PCOS and diet has looked at Mediterranean diets or general calorie restriction, so this review adds new information about whether the keto approach specifically might be helpful.

Several important limitations should be considered: The review didn’t specify the total number of women studied across all eight studies, making it hard to understand how much evidence this really represents. Most studies appear to have been short-term, so we don’t know if benefits last over months or years. The studies likely had different quality levels and designs, which makes it harder to combine their findings. The review doesn’t tell us whether certain groups of women (like those with specific PCOS presentations) benefit more than others. Finally, without knowing details about how the studies were conducted, we can’t fully assess how reliable these findings are.

The Bottom Line

Based on this review, a ketogenic diet may be worth discussing with your doctor if you have PCOS and want to try dietary changes to manage your symptoms. The evidence suggests short-term benefits for weight loss and blood markers are likely (moderate confidence level). However, because most studies were short-term, we have lower confidence about long-term benefits. If you try a ketogenic diet, work with a healthcare provider or registered dietitian to make sure it’s appropriate for you and to monitor your progress.

This research is most relevant for women with PCOS who are interested in dietary approaches to manage their condition. It may be particularly interesting for women who haven’t had success with other diets or who want to try a structured eating plan. However, women who are pregnant, breastfeeding, have a history of eating disorders, or have certain medical conditions should talk to their doctor before trying a ketogenic diet. Men don’t have PCOS, so this doesn’t apply to them.

Based on the studies reviewed, weight loss and improvements in blood markers may appear within weeks to a few months of starting a ketogenic diet. However, most studies were short-term, so we don’t know how long these benefits last if you stay on the diet long-term, or what happens if you stop. Realistic expectations are that you might see changes in 4-12 weeks, but you should plan to work with a healthcare provider to monitor your progress and adjust as needed.

Want to Apply This Research?

  • Track daily carbohydrate intake (aiming for under 50g per day for a strict keto approach) and weekly weight. Also monitor menstrual cycle regularity by marking period start dates and noting any changes in cycle length or symptoms like cramping or heavy bleeding.
  • Start by identifying and replacing high-carb foods you eat regularly with keto-friendly alternatives (for example, replacing bread with lettuce wraps, or pasta with zucchini noodles). Use the app to log meals and see your carb totals, making it easier to stay within keto targets without feeling deprived.
  • Set up weekly check-ins to review carb intake patterns and weight trends. Every 4-6 weeks, note any changes in energy levels, menstrual regularity, or PCOS symptoms. If possible, work with your doctor to recheck blood work (hormone levels, blood sugar, lipids) every 3 months to see if the diet is producing the improvements shown in the research.

This review summarizes research on ketogenic diets for PCOS but is not medical advice. PCOS is a complex condition that requires individualized treatment. Before starting a ketogenic diet or making significant dietary changes, consult with your doctor or a registered dietitian, especially if you are pregnant, breastfeeding, have diabetes, or take medications. While the reviewed studies show promising short-term results, long-term safety and effectiveness of ketogenic diets for PCOS require further research. This information is for educational purposes and should not replace professional medical guidance.