Can Inositol Help Manage PCOS Symptoms?

Article by Claire Johnson

Polycystic ovary syndrome (PCOS) is a complicated but common hormonal issue thought to affect up to 20% of reproductive aged women [1]. The most common signs and symptoms of PCOS are irregular periods, lack of ovulation, fertility issues, weight gain, hirsutism (which is where where women have thick, dark hair on their face, neck, chest, tummy, lower back, buttocks or thighs) and male-pattern balding.

What is PCOS?

PCOS diagnosis must be confirmed by a doctor, which often involves an ultrasound of the ovaries to identify cysts (undeveloped follicles), as well as blood tests to identify abnormal hormone levels.

Since PCOS is a ‘syndrome’, it means that symptoms can occur together or independently, and this will vary hugely between individuals. Whilst PCOS cannot be ‘cured’ as such, there is a large, emerging field of research dedicated to helping women manage this condition, regain hormonal balance, fertility, ovulation and menstrual cycle regularity. In addition to lifestyle and dietary changes, an important supplement at the forefront of this research is inositol. 

Why does PCOS occur?

While the exact causes of PCOS are still not fully understood, there are three key mechanisms which scientists believe to be at the centre of PCOS and its symptoms [2]. These are; 

  1. Insulin Resistance: where our cells become resistant to the hormonal messages of insulin, causing higher blood glucose (blood sugar levels) and insulin levels. 

  2. Excess male hormones: higher levels of male hormones such as androgens, DHEAs and testosterone can disrupt the delicate balance of our reproductive hormones. 

  3. Inflammation: long-term inflammation may also play a role in disrupting insulin signalling and hormonal balance. 

PCOS researchers suggest that all three of the above may be interrelated to varying degrees depending on a number of factors, including genetics, which might explain the huge differences in symptom severity experienced amongst those with PCOS.

What is inositol and will it cure my PCOS?

Unfortunately, PCOS cannot be cured but symptoms can be managed and hormonal balance can be restored. Inositol is a naturally occuring compound in the body that is often found to be lower or imbalanced in women with PCOS [3]. Inositol helps our bodies manage blood sugar and insulin, which we know many women with PCOS struggle with. 

Some foods can provide us with inositol and are a great addition to a healthy balanced diet.

Foods naturally high in inositol include; 

  • Beans (of all kinds)

  • Nuts and seeds (of all kinds) 

  • Vegetables such as broccoli, sprouts, carrots, tomatoes and cabbage 

  • Fresh fruits such as bananas, cantaloupe, oranges, apples, pears 

  • Whole grains such as oats, quinoa and brown rice

  • Eggs

  • Dairy such as yoghurt and cheese 

However, inositol supplementation is often recommended for women with PCOS who may need an additional boost. As a result, many scientists have turned their research towards inositol supplementation and its ability to reduce insulin resistance and male hormones, restore ovulation and increase menstrual cycle regularity.

 Here are some exciting findings from studies exploring the role of inositol in women with PCOS…


Restoring Ovulation and Menstrual Cycle Regularity

Menstrual irregularity and lack of regular ovulation are common characteristics of PCOS, however, research has consistently found that inositol supplementation can help restore menstrual cycles and ovulation. One study revealed that a daily dose of 4 grams of inositol improved menstrual cycle regularity in both lean and obese PCOS women [4]. Another study in 600 women with PCOS found that inositol supplementation significantly increased ovulation rate as well as the frequency and regulation of menstrual cycles 6-fold, without any reported negative side effects [5]. These findings highlight the potential of inositol in normalising and promoting regular menstrual cycles and ovulation.


Balancing Hormones

High androgen, DHEAs and testosterone levels contribute to commonly reported PCOS symptoms such as hirsutism, male-pattern balding and acne. Research has found that when women with PCOS take inositol, their levels of androgens, testosterone and DHEAs are reduced, suggesting that inositol can help restore hormonal balance [5]. 


Improving Insulin Sensitivity:
 

Since insulin resistance has been found to play a key role in PCOS and the worsening of symptoms, multiple studies have looked at inositol’s ability to reduce insulin resistance. The positive effects of inositol in reducing insulin resistance have been studied for decades, with both old and new research confirming that inositol supplementation may improve blood sugar levels, insulin levels and insulin resistance in women with PCOS [5] [6]. 

Which inositol should I take?

There are a number of different inositol supplements on the market containing differing amounts of inositol. The most common inositol supplement is made up of two inositol compounds called myo-inositol and d-Chiro inositol in a ratio of 40:1. Recent research suggests that combining 2000mg of myo-inositol and 50mg of d-chiro inositol in this ratio offers the greatest amount of benefit to women with PCOS.  

With this mounting evidence in favour of inositol supplementation, The International Evidence-based Guideline for the Assessment and Management of PCOS now recommends inositol therapy as an official clinical approach to PCOS management [7]. Remember though it’s always best practice to always consult a registered healthcare professional that has the relevant qualifications first before taking any new supplements. 


Conclusion

Both past and present research on inositol supplementation in women with PCOS has found promising results regarding the management of symptoms, especially in reducing male hormones and insulin resistance which can then improve menstrual cycle regularity and ovulation. Since little to no side effects are reported with inositol, it offers a more tolerable and effective solution compared with other frequently prescribed PCOS drugs which can cause digestive upset. More in depth research into the causes of PCOS and the efficiency of inositol are still underway, but for now inositol can be considered a safe and effective solution for PCOS management, especially supplements which contain myo-d+d-chiro inositol in a ratio of 40:1.

This blog post was written by Claire Johnson, a Clinical Nutrition Masters student at The University of Roehampton in London. Claire has dedicated the past four years to research and study within female health and hormones, specialising in PCOS, fertility, healthy weight loss and menstrual cycle health. Claire is on a mission to empower and educate women so that they can take their health into their own hands, especially when it comes to hormonal health and commonly under-researched female hormonal conditions. You can find her on Instagram @hormonalhealthcoach.

References:

(1) Greff, D. et al. (2023) Inositol is an effective and safe treatment in polycystic ovary syndrome: A systematic review and meta-analysis of randomized controlled trials, Reproductive Biology and Endocrinology, 21(1), pp.10. doi:10.1186/s12958-023-01055-z.

(2) Laganà, A.S. et al. (2018) Inositol in polycystic ovary syndrome: Restoring fertility through a pathophysiology-based approach, Trends in Endocrinology & Metabolism, 29(11), pp.768-780. doi:10.1016/j.tem.2018.09.001.

(3) Papaleo, E., Unfer, V., Baillargeon, J. P., De Santis, L., Fusi, F., Brigante, C., Marelli, G., Cino, I., Redaelli, A., & Ferrari, A. (2007). Myo-inositol in patients with polycystic ovary syndrome: a novel method for ovulation induction. Gynecological endocrinology : the official journal of the International Society of Gynecological Endocrinology, 23(12), 700–703 doi.org/10.1080/09513590701672405

(4) Zacchè, M.M. et al. (2009) Efficacy of myo-inositol in the treatment of cutaneous disorders in young women with polycystic ovary syndrome, Gynecological Endocrinology, 25(8), pp.508-513. doi:10.1080/09513590903015544.

(5) Pundir, J. et al. (2018) Inositol treatment of anovulation in women with polycystic ovary syndrome: A meta-analysis of randomised trials, BJOG: An International Journal of Obstetrics & Gynaecology, 125(3), pp.299-308. doi:10.1111/1471-0528.14754.

(6) Nestler, J.E. et al. (1999) Ovulatory and metabolic effects of d-chiro-inositol in the polycystic ovary syndrome, N Engl J Med, 340(17), pp.1314-1320. doi:10.1056/NEJM199904293401703.

(7) Teede, H.J. et al. (2018) Recommendations from the international evidence-based guideline for the assessment and management of polycystic ovary syndrome†‡, Human Reproduction, 33(9), pp.1602-1618. doi:10.1093/humrep/dey256.