Inositol and PCOS

Updated May 2022

Since writing the Honest, Hairy Truth articles, I’ve had a lot of questions and feedback from many of you wanting more information on Inositol and PCOS. For some of those who have tried it, the results have been dramatic, with one woman losing 21 pounds in a month since taking it. For some of those who have tried it, the results have been dramatic I have to say that my results have not been as dramatic but I have seen a slight improvement in my weight and hirsutism.

Inositol is absolutely one of my favourite PCOS supplements and, together with a good PCOS diet, it has made a huge impact on my symptoms. To find out more about how to manage PCOS naturally, you should check out my FREE training, “How to Manage PCOS Naturally.


What is Inositol?

Inositol is a naturally occurring substance that used to be considered as one of the B vitamins. The body is able to produce it on its own, though, so it isn’t considered a vitamin anymore.

Inositol is the common name given to Myo-Inositol. So generally, if you see Inositol supplements, it is Myo-Inositol on the bottle.

This is important because myo-inositol is part of a family of 9 forms of inositol, otherwise known as an “isomer”. This gets a bit technical so bear with me. An isomer has the same technical composition and arrangement of molecules but the placement of the atoms differs.

Huh? Basically, there are nine compounds in the Inositol family that are all basically identical except for one minor change between each. This means that if your body is lacking in one form of Inositol, it can convert one of the other compounds into the one that is lacking.


What does Inositol do?

pcos and inositol two spoons with white powder and two white capsulesIt seems that Inositol has two jobs really. The first one is that it is important in the insulin receptors of each cell. The receptor is on every cell wall and works as a lock and key mechanism. Insulin needs to fit just right for the receptor to open and let the insulin work its magic on the cell. If the receptor isn’t working very well, your body produces more insulin to compensate, leading to insulin resistance. Inositol helps the receptor work more efficiently so Insulin can bind properly the first time, causing your body to not produce too much insulin.

Its second job involves the Insulin signaling pathway. Now, I’m not a Biochemist but my understanding of inositol’s role in insulin signalling is as follows. As insulin attaches to the cell wall, it sets in a motion a series of changes within the cell. Inositol plays a role in this series of changes and it is important for insulin to be effective within the cell. (1)

Inositol is also involved in stopping insulin’s effect on the cell. In a sense, it helps to flip the off switch.

Right, that’s most of the technical stuff over, I hope.


Inositol and PCOS

Let’s move on to the good stuff… Why we should all be taking Myo-inositol.

I could give you loads of research articles but I’m just going to give you the summarized version of the effects of Inositol on PCOS (2):


  • Increased progesterone
  • Increased SHBG (sex hormone binding globulin) – Deals with any free testosterone in our blood stream
  • Lowered testosterone levels
  • Improved insulin sensitivity
  • Decreased luteinizing hormone
  • Induced weight loss (that sounds good to me)
  • As mentioned in my Honest Hairy Truth post, it has also been shown to be effective in managing hirsutism


PCOS and inositol happy womanThere is also some good research on how myo-inositol supplementation helps with fertility and pregnancy. Inositol has been shown to:

    • Restore normal ovulatory activity and ovulation induction, leading to improved fertility in women with Polycystic Ovary Syndrome
    • Improve egg quality and pregnancy rate in women with failed IVF and thereby improve IVF outcomes
    • Improve pregnancy rate and lower cancellation rate in women with PCOS

Although myo-inositol is safe to take throughout pregnancy and whilst breastfeeding, please check with your doctor if you do fall pregnant while taking it.


How much and how?

Inositol is available in capsules and powdered form. The research studies were conducted using 4g per day of inositol and combining it with Folic Acid. If you take 4g in capsule form, you’ll land up taking a lot of capsules (I found 500mg capsules so I would need to take 8 a day).

The powdered form is mixed in a glass of water. It has a slightly sweet taste and I can hardly taste it. So, when I started taking Inositol, I started with the Jarrow Formulas Inositol Powder, 227g which is available on

Ovasitol from Theralogix is also a great option. It combines two kinds of inositols – D-chiro-inositol and myo-inositol – in a 40:1 ratio. This is the same ratio that these two inositols are found in the body. There is strong evidence for both D-chiro and myo-inositol and PCOS. So, this is what I now take. You can get Ovasitol (using PRC code 144144) at the best price here.

You may also have heard of Cystofert for PCOS. Cystofert is a similar combination of D-chiro-inositol and Myo-Inositol but it only has 1100mg per tablet, as opposed to the recommended 2g of inositol per dose.


Some Commonly Asked Questions About Myo-Inositol Supplementation


How long does Myo-inositol take to work in women with Polycystic Ovarian Syndrome?

We all tend to want results and want them now (I’m exactly the same!) Some women report seeing improvements within a week – weight loss or a reduction in cravings. But, we need to remember that it takes at least 3 months for an egg to be developed in the ovary. So, we need to give Inositol at least 3 months before we can see maximum benefits. So be patient and give it some time. It will be worth the wait!


How long does it take for myo-inositol to regulate periods?

PCOS and Inositol periodWe know that one of the hallmarks of PCOS is an irregular menstrual cycle. This can make trying to conceive incredibly frustrating!

As mentioned already, it takes 3. months for oocyte maturation and therefore you need to be ton inositol treatment for at least 3 months before you can expect a more regular period.


Do you know of any myo inositol PCOS weight loss success stories?

When it comes to losing weight with PCOS, it’s always a bit of a tricky one. many of us want to lose weight but our hormones are playing havoc!

The good news is that Inositol has been shown to help with weight loss in PCOS.

One study compared 3 weight loss methods in obese PCOS patients. They compared the use of Myo-inositol, diet and combined therapy myo inositol (mi) and d-chiro inositol (dci). The results showed that those women who used the combined mi and dci, as well as a good PCOS diet, had the most accelerated weight loss (3).

I have been using Inositol (Ovasitol in particular), and found that when I initially started taking inositol, my cravings were much more under control and I did have some success with weight loss.


Are there any side effects to taking inositol?

There are very few side effects when taking myo-inositol. It is a very safe supplement to take.

Some people may experience mild side effects such as nausea, stomach cramps and headaches, which usually resolve after a few days.


Can Inositol help with Gestational Diabetes?

PCOS and Inositol pregnant woman checking blood sugar levelsOne of the many impacts of PCOS is the increased risk of gestational diabetes. The wonderful news is that myo inositol reduces the risk of gestational diabetes.

A randomized controlled trial have compared women who have been diagnosed with gestational diabetes using an oral glucose tolerance test. Some women supplemented with myo inositol whilst others took folic acid on it’s own (4).

Those women who took myo inositol showed increased insulin sensitivity and a lowered risk of developing gestational diabetes.


Can you get Inositol Over the Counter?

The good news is that inositol is available over the counter, without a prescription. If you are concerned about taking inositol, please do speak to your doctor before you start taking inositol as part of your PCOS treatment plan.


Do you recommend Myo inositol administration with Metformin?

PCOS and Inositol thumbs upIf you are struggling with insulin resistance and glucose metabolism, you may have been prescribed Metformin, an insulin-sensitizing drug.

Both metformin and inositol help to improve insulin sensitivity. This means that taking both together may result in lower glucose levels. Some of the women that I have worked with have found that taking slightly less inositol can prevent this.

If you are uncertain about the effect of Metformin and Inositol together, please do speak to your doctor before starting on Inositol.


Summing it Up

So, all of the research on Inositol looks promising for women with PCOS. I have been taking Inositol for years and really feel the difference in my cravings when I am not taking it. I’d love to hear about your experiences of Inositol and if it’s helped you with any of your PCOS symptoms. Please leave me a comment below and we can share the inositol love!

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1Hooper, Claudie. “An Overview of Insulin Signaling Pathways | Abcam.” An Overview of Insulin Signaling Pathways | Abcam,, 0 0 2000,

2“Miscarriage Research – Inositol.” Miscarriage Research – Inositol,, Accessed 9 May 2022.

3Le Donne, M., et al. “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 – PubMed.” PubMed,, 1 Mar. 2019,

4Tahir, F., and Z. Majid. “Inositol Supplementation in the Prevention of Gestational Diabetes Mellitus – PMC.” PubMed Central (PMC),, 1 Sept. 2019,

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Tarryn Poulton

Tarryn Poulton

Tarryn Poulton is a PN1 Certified Nutrition Coach and PCOS expert who has been a leader in the online PCOS space for over 8 years. Tarryn has the support of leading clinicians from around the world who support her scientific approach to understanding and talking about PCOS this includes all medical journals and ongoing research. You can read more about Tarryn and the team here.

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