Blog Post

Supplements for PCOS: A Dietitian’s Guide

Supplements for PCOS

When it comes to PCOS, there are quite a few supplements that can help. Prioritising your overall nutrition will help far more than any individual supplement, but supplements can certainly provide some value.

When it comes to supplements, often they are only beneficial whenever there is a deficiency or inadequate intake. Adding the supplement in addition to an already optimal intake likely won’t provide any additional benefit.

So, keep that in mind since a lot of these needs can be met through food as well. Supplements are just the icing on the cake. If you would like to learn more about nutrition in general for PCOS, I recommend reading this post.

PCOS can’t technically be cured but these might help reduce symptoms related to menstruation, excess hair growth, ovulation, fertility, testosterone, insulin resistance and many more.


There is a lot of solid evidence for how Inositol can help people with PCOS. It appears to improve insulin sensitivity, lower testosterone and aid fertility.

The recommended dosage is 2-4g per day of myo-inositol.


Magnesium can help improve insulin sensitivity and if taken at night, reduce fasting blood glucose levels (BGL’s).

The recommended dosage is 300-400mg taken one hour before going to bed, however, I would wager that if you meet your magnesium needs through foods, this won’t be necessary. The vast majority of people do not meet the RDI for magnesium through food though. Therefore this potentially could be helpful for quite a few people.

Omega 3’s

Omega 3’s can help reduce inflammation and improve metabolic markers such as cholesterol and blood pressure. It may also help reduce testosterone and help with the regularity of the menstrual cycle.

Ideally, you would obtain this through food by consuming fish 2-3 times per week (where at least one time is oily fish such as salmon) or consuming plant-based options such as seeds or walnuts.

If you are supplementing, the recommended dosage is 1000-3000mg daily.


Zinc can be effective for reducing hair growth or reducing hair loss associated with PCOS. It can also potentially help reduce insulin resistance.

The dosage used in research is 50mg/per day, which is significantly higher than the RDI of 8mg/day. For reference, most people do not reach the RDI consistently through food.


Cinnamon may help under certain circumstances. It can potentially help menstrual cycle irregularities. It can also aid blood glucose control by improving the use of glucose in cells and also slowing the rate at which glucose enters the blood.

The recommended dosage is 1-2g per day.

N-acetylcystein (NAC)

There is a bit of research indicating that NAC may lead to improvements in pregnancy and ovulation rates. For me, this is a bit of a watch this space area though as the evidence isn’t very strong yet.

NAC increases the cellular levels of antioxidants and reduces glutathione at higher doses. Theoretically, this can translate to improved insulin sensitivity, but the current research doesn’t support that in practice.

The dosage commonly used in research is 1200-1800mg per day.


Berberine is a Chinese medicinal herb. It may help with insulin resistance and also other metabolic markers, but more controlled research is needed.

The dosage recommended for PCOS is 1.5g daily.


A systematic review of 7 randomised control trials featuring chromium demonstrated that chromium could potentially help reduce insulin resistance and testosterone. It does not appear to improve ovulation, however.

The recommended dosage is 200µg daily of chromium picolinate.

Vitamin D

Vitamin D is another supplement that has a bit of evidence of improving insulin resistance.

A lot of people with PCOS happen to be deficient in vitamin D. But that leads to a chicken or the egg scenario: Does PCOS contribute to deficiency, or does deficiency contribute to PCOS? Either way, supplementation will only likely be beneficial if you are deficient.

The first step should be to get a blood test for deficiency and then address it from there. The recommended dosage is 1000IU per day, or higher if your doctor recommends it. It is not uncommon for people to supplement as high as 10,000IU per day while addressing a deficiency.


None of these supplements are necessary and they won’t individually make a massive difference. They can help address certain symptoms under specific circumstances though. It is certainly worth looking into and considering whether they could possibly be of benefit for you.

By Aidan Muir

Aidan is a Brisbane based dietitian who prides himself on staying up-to-date with evidence-based approaches to dietetic intervention. He has long been interested in all things nutrition, particularly the effects of different dietary approaches on body composition and sports performance. Due to this passion, he has built up an extensive knowledge base and experience in multiple areas of nutrition and is able to help clients with a variety of conditions. One of Aidan’s main strengths is his ability to adapt plans based on the client's desires. By having such a thorough understanding of optimal nutrition for different situations he is able to develop detailed meal plans and guidance for clients that can contribute to improving the clients overall quality of life and performance. He offers services both in-person and online.