How are PCOS, Inositol, and Weight Connected?
By OBGYN and fertility expert Dr. Kenosha Gleaton
Whether you have polycystic ovary syndrome (PCOS) or you’re just hoping to improve your overall health, it can feel like losing weight is impossible. Weight loss is never as simple as taking a magic diet pill, but research does show that certain medications or supplements may support weight loss goals when paired with lifestyle changes. Let’s talk about PCOS, weight management, insulin sensitivity, and inositol.
Inositol’s role in the body
Inositol is a naturally occurring sugar that has an important role in hormone signaling, balancing chemicals, cell growth, and more.  There are multiple forms of inositol found in the body, but the two most common are myo-inositol (MI) and d-chiro-inositol (DCI).  These two forms of inositol are especially important for glucose absorption, metabolism, and storage. This connection to glucose is what makes inositol a useful supplement for many with PCOS, metabolic syndrome, gestational diabetes, and other conditions.  Inositol can be found in certain foods and is also available in the form of dietary supplements.
Weight and fertility
If you are hoping to conceive soon or if you’re currently pregnant, it’s important that you know about the impact weight has on reproductive health. Successful ovulation is most likely to occur in those of a healthy weight. A healthy weight can look different for everyone depending on your age, height, and more; your healthcare provider can provide more guidance on what a healthy weight might be for you. This means that anyone severely underweight or overweight may have difficulty conceiving due to anovulation or irregular cycles.  Overweight and obese women also have a higher risk of miscarriage and pregnancy complications. Obesity also increases the risk of diabetes, hypertension, heart disease, and some forms of cancer. 
For those that are overweight or obese and hoping to decrease their risk of infertility or pregnancy complications, losing weight may help support reproductive outcomes.  Losing weight in a healthy manner should be prioritized, as overexercising and under eating have negative health effects and may also cause difficulty conceiving.  A healthcare provider should be consulted when attempting to lose or gain weight, especially when attempting to improve reproductive health outcomes.
Keep in mind that plenty of overweight women have successful and healthy pregnancies. You don’t necessarily have to lose weight to conceive, but you may want to discuss your TTC goals and plans with your healthcare provider.
If you need a recap, PCOS is an endocrine disorder occurring in up to 12% of people assigned female at birth in the United States.  PCOS is characterized by a number of symptoms, including an increase in male hormone levels, the presence of multiple cysts on the ovaries, and irregular ovulation. Many with PCOS are insulin resistant, meaning their body has a difficult time using insulin effectively.  Other common symptoms seen in those with PCOS include acne, male pattern hair growth, thinning hair, irregular periods, and an increased risk of obesity, diabetes, heart disease, and more. 
PCOS and weight
What is the connection between PCOS and weight? While the exact relationship between PCOS and being overweight isn’t known, we do know that the two are connected somehow.  It’s hypothesized that increased levels of male hormones play a role in weight gain. Not everyone with PCOS is overweight, and not all overweight people have PCOS, but data shows there is definitely a correlation between the two. In fact, some research suggests that around 80% of those in the United States with PCOS are considered overweight or obese. 
Does inositol help with weight loss?
As most of us know, weight loss requires more than taking a supplement. It’s important to incorporate a healthy diet and exercise when attempting to lose weight. That being said, some data does suggest that inositol may help with weight loss, body mass index (BMI) reduction, as well as restoring regular menstrual cycles and supporting ovarian function. [8-9] Most studies involve PCOS patients, although some data does suggest that inositol may also help with weight loss in adults under 30 years of age. [8-9] The average dose administered in these studies ranged from 600 to 4,450 mg/day for up to 48 weeks. You should always speak to your healthcare provider before taking any supplements.
Inositol’s role in weight loss is likely tied to its beneficial effects on insulin sensitivity. When the body is resistant to insulin for long periods of time, more insulin is produced, which can lead to weight gain, causing insulin resistance to worsen.  This is essentially a cyclical pattern sometimes seen in those with PCOS and/or overweight or obese individuals. Inositol helps the body absorb, store, and metabolize glucose, aiding in insulin sensitivity and therefore aiding in weight loss.  Remember that inositol alone isn’t likely to help you lose weight, but may be useful to take in addition to diet and exercise with the approval of your healthcare provider.
Inositol vs. metformin for weight loss
Metformin is an antidiabetic used to treat type 2 diabetes, but is also commonly prescribed to aid in the treatment and prevention of PCOS.  Metformin works to reduce blood glucose levels, reduce glucose production, and increase insulin sensitivity. Some studies have also researched metformin’s effects on weight loss in those with PCOS or diabetes.  When comparing metformin and inositol for weight loss, data is mixed. Some studies show that there isn’t much of a difference between the two, whereas others seem to favor metformin for weight loss and inositol for ovarian health and cycle regularity. [13-15] Metformin is more likely to cause uncomfortable gastrointestinal side effects and requires a prescription, whereas inositol tends to have fewer side effects and is found over the counter. [13-15] You should consult your healthcare provider about your options prior to taking any supplements or medications.
Other tips for weight loss
If you are hoping to lose weight, there are a few things you should keep in mind. Healthy weight loss doesn’t have to be extreme and may not always be noticeable. Losing even 5% to 10% of your total body weight has been shown to provide health benefits and may improve PCOS symptoms. [16-17] Data also shows that limiting starch and dairy may aid in weight loss and insulin sensitivity. 
Instead of sticking to unsustainable diets or extreme workout regimes, attempt to slightly alter your lifestyle habits where possible. Some examples of sustainable lifestyle changes include:
- Increasing intake of water and unsweetened beverages and cutting out soda or sugary drinks.
- Going on walks every day or every other day, or signing up for a new workout class a few times a week.
- Gradually increase the amount of time you spend working out or being active.
- Cut back on fast food or eating out.
- Manage your stress in healthy ways such as a new hobby, going for a walk, or catching up with a friend.
- Cut back on alcohol.
If you aren’t satisfied with your results or you’re having a hard time losing weight, speak to your healthcare provider for additional recommendations.
- Inositol is a sugar found in the body that impacts hormone signaling, cell growth, and chemical balancing.
- Being overweight or underweight can negatively impact reproductive outcomes, including an increased risk of anovulation and negative pregnancy outcomes.
- PCOS is an endocrine disorder that impacts up to 12% of females in the United States.
- PCOS and weight gain are correlated, although the direct relationship between the two is still unknown.
- Research suggests that taking inositol in addition to healthy lifestyle changes may support weight loss and reduce BMI in both people with PCOS and adults under 30.
- Inositol has also been shown to help regulate ovulation and improve ovarian function in those with PCOS.
- Another common medication used for PCOS symptoms and weight loss is metformin, although metformin is associated with more side effects than inositol.
- Losing even a small amount of weight has been shown to improve PCOS symptoms and overall health.
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- Evenson KR, Hesketh KR. Studying the Complex Relationships Between Physical Activity and Infertility. Am J Lifestyle Med. 2016;10(4):232-234. doi:10.1177/1559827616641379
- PCOS (Polycystic Ovary Syndrome) and Diabetes. Centers for Disease Control and Prevention. December 30 2022. URL.
- Sam S. Obesity and Polycystic Ovary Syndrome. Obes Manag. 2007;3(2):69-73. doi:10.1089/obe.2007.0019
- Le Donne M, Metro D, Alibrandi A, Papa M, Benvenga S. Effects of three treatment modalities (diet, myoinositol or myoinositol associated with D-chiro-inositol) on clinical and body composition outcomes in women with polycystic ovary syndrome. Eur Rev Med Pharmacol Sci. 2019;23(5):2293-2301. doi:10.26355/eurrev_201903_17278
- Zarezadeh M, Dehghani A, Faghfouri AH, et al. Inositol supplementation and body mass index: A systematic review and meta-analysis of randomized clinical trials. Obes Sci Pract. 2021;8(3):387-397. Published 2021 Oct 22. doi:10.1002/osp4.569
- Insulin Resistance. Cleveland Clinic. December 16 2021. URL.
- DiNicolantonio JJ, H O'Keefe J. Myo-inositol for insulin resistance, metabolic syndrome, polycystic ovary syndrome and gestational diabetes. Open Heart. 2022;9(1):e001989. doi:10.1136/openhrt-2022-001989
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- Treatments to Relieve Symptoms of PCOS. NIH Office of Communications. January 31 2017. URL.
- Phy JL, Pohlmeier AM, Cooper JA, et al. Low Starch/Low Dairy Diet Results in Successful Treatment of Obesity and Co-Morbidities Linked to Polycystic Ovary Syndrome (PCOS). J Obes Weight Loss Ther. 2015;5(2):259. doi:10.4172/2165-7904.1000259