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I have PCOS, do I need to take supplements?

What is PCOS?

Polycystic Ovary Syndrome, or PCOS, is a hormonal condition that affects 1 in 10 reproductive-aged women.

Symptoms of PCOS can vary from person to person, but some common symptoms include absent/ irregular periods, excessive facial and body hair, acne, weight gain, and difficulties getting pregnant.

PCOS may be diagnosed if you have two or more of the following symptoms:

- Irregular or no periods.

- Signs or symptoms of high levels of androgens (e.g. acne/excess hair growth) or high androgen levels (shown in your blood test).

- Polycystic ovaries shown on an ultrasound scan.


There's no cure for PCOS but symptoms can be improved by following a healthy balanced diet and making some lifestyle changes. There is also scientific research to show that some nutritional supplements can improve certain aspects of PCOS.

In this blog article I’ll provide a list of some effective and common supplements used among women with PCOS.


Please speak to your doctor, dietitian or healthcare professional before starting any supplement regime to ensure it is right for you and does not interact with any other medications or supplements that you are taking. 

Vitamin D

Vitamin D is a fat-soluble vitamin that is needed for the absorption of calcium. The main source of vitamin D is from exposure to UV sunlight and only a small amount of our daily vitamin D requirements is obtained from food sources. You can find small amounts of it in oily fish, red meat, egg yolks, and in fortified foods. In the UK, Vitamin D deficiency is common, and it is recommended that all adults take 10 micrograms of vitamin D in the winter months (1).

Lower levels of vitamin D have been shown in women with PCOS. Vitamin D affects reproduction, as it is involved in follicle egg maturation and development. Supplementation with vitamin D may improve ovulation and conception in women with PCOS (2). It has also been linked to improved insulin sensitivity and help to control blood glucose levels in women with PCOS (3). Therefore, if you have PCOS you might want to take a daily 10 microgram vitamin D supplement all year round.



Inositol is a B-type vitamin and it’s found in fruits, pulses, grains and nuts and the body also makes it. There are two main forms of inositol: myo-inositol (MI) and D-Chiro inositol (DCI).

Both forms have a number of functions in the body, including influencing the action of insulin and controlling blood glucose levels. They have also been shown to affect reproduction and improve metabolic issues.

Research shows that women with PCOS may be at risk of inositol deficiency, and supplementation of MI and DCI have shown favourable results in improving nearly all aspects of PCOS including insulin sensitivity and improving blood glucose control (4).

A recent study has also found that inositol can help to promote ovulation, regulate menstrual cycles, and improve egg quality (5). Another study showed a decrease in triglycerides, testosterone, and blood pressure levels in women with PCOS (6).

The naturally occurring ratio of these two forms of inositol is 40:1, meaning for every 40mg of MI, there is 1mg of DCI. Therefore, it is suggested that supplements containing this ratio might be optimal for managing PCOS symptoms. Most studies showing beneficial effects have used a divided dose (taken twice a day) of between 2g to 4g per day.

Since it may lower blood glucose and insulin levels, please speak to your GP or health care professional if you plan to take this, particularly if you are already taking metformin.

Omega-3 Fatty Acids

EPA and DHA are long-chain omega-3 fatty acids. They assist in brain and eye development; cognitive function and they also have anti-inflammatory properties that benefit the immune system, improve insulin sensitivity and protect against heart disease. A diet rich in omega-3 fatty acids from foods such as oily fish, (salmon, mackerel, herring, trout and sardines), nuts and seeds is recommended for general health and wellbeing.

Omega- 3 fatty acids have been found to offer a range of health benefits to women with PCOS, including increased insulin sensitivity, lowered triglycerides and androgens, decreased inflammation, and improved symptoms of depression (7).

Including at least two servings of oily fish per week provides you with enough omega-3 fatty acids. If you don’t eat fish, a fish oil supplement or an algae omega-3 supplement (providing at least 200mg DHA per day) may be beneficial if you have PCOS.



Cinnamon is a popular spice that has been used for thousands of years for its taste enhancement and potential medicinal benefits. It is derived from the dried inner bark of evergreen trees grown in South Asia (Ceylon cinnamon) and Southeast Asia (Chinese cinnamon).

It has been found to improve insulin function and insulin sensitivity in women with PCOS (8). Another trial involved women with PCOS taking cinnamon supplements (1.5g daily) for 6 months and showed promising results with improving menstrual cyclicity and may be an effective treatment option for some women with PCOS (9).

More research is required to determine the recommended dose to benefit women with PCOS. Most of the studies use amounts ranging from 1-6g daily. One teaspoon of ground cinnamon equals 3g and this can be easily sprinkled on foods such as cereal, oats, hot drinks or taken in capsule form.

As it may lower blood glucose and insulin levels, it’s important that you speak to your GP or healthcare professional if you're planning to take this.

The Bottom Line

In summary, some nutritional supplements have shown promising results in improving PCOS. However, they’re not to be used as a substitute for a healthy balanced diet. Caution should also be taken when using any supplements, as they may lower blood sugar levels.

It is important that you speak to your GP or healthcare professional before starting or altering a dose of supplement.

Working alongside a Dietitian can help to improve PCOS symptoms.

If you’re looking for more personalised support to help you to manage your PCOS, please feel free to contact me.


  1. NHS, (2020) Overview Vitamins and Minerals. Available from:

  2. Thomson, RL., Spedding, S., Buckley, JD. Vitamin D in the aetiology and management of polycystic ovary syndrome. Clinical endocrinology. 2012; 77 (3): 343-350.

  3. Asemi, Z., ‘Calcium Plus Vitamin D Supplementation Affects Glucose Metabolism and Lipid Concentrations in Overweight and Obese Vitamin D Deficient Women with Polycystic Ovary Syndrome’. Clinical Nutrition 34, n0.4 (August 2015): 586-92.

  4. Pizzo, A., Lagana, AS, Barbaro, L. Comparison between effects of myo-inositol and D-chiro-inositol on ovarian function and metabolic factors in women with PCOS. Gynecological endocrinology 2014 Mar; 30 (3): 205-8.

  5. Dona, G., Sabbadin, C., Fiore, C., et al. Inositol administration reduces oxidative stress in erythrocytes of patients with polycystic ovary syndrome. European Journal of Endocrinology. 2012; 166 (4): 703-710.

  6. Costantino, D., Minozzi, G., Minozzi, E., Guaraldi, C. Metabolic and hormonal effects of myo-inositol in women with polycystic ovary syndrome: a double-blind trial. European Review of Medical Pharmacological Sciences. 2009;13 (2): 105-110.

  7. Oner, G., Muderris, II. Efficacy of omega-3 in the treatment of polycystic ovary syndrome. Journal of Obstetric Gynaecology. 2013; 33 (3): 289-291.

  8. Wang JG., Anderson, RA., Graham, GM et al. The effect of cinnamon extract on insulin resistance parameters in polycystic ovary syndrome: a pilot study. Fertility and Sterility. 2007; 88 (1): 240-243.

  9. Kort DH., Lobo, RA. Preliminary evidence that cinnamon improves menstrual cyclicity in women with polycystic ovary syndrome: a randomized controlled trial. American Journal of Obstetrics and Gynaecology. 2014 Nov; 211 (5): 487.e1-6.


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