Inositol Or Metformin: What The Evidence Shows

If you’ve been following the PCOS Nutrition Center blog, you know what a fan we are of a combination of myo and d-chiro inositol (DCI) for pretty much any woman with PCOS, regardless of age or fertility. New research is starting to compare the benefits of inositol to metformin in women with PCOS. The results may surprise you!

Why do we like Ovasitol so much? Because of the numerous health benefits it offers women with PCOS such as:

 

How Does Inositol Work?

Inositols are secondary messengers. The best explanation of this that I give to my PCOS nutrition coaching patients goes like this: when we eat foods (mostly carbohydrates), they get converted into glucose in our blood stream. We need the glucose to enter our cells to be used for energy. When blood glucose levels rise, a signal (imagine a doorbell is rung) is sent from the cell door to the nucleus telling it to open up. However, with PCOS, the doorbell on the cell door may be defective. This means that it takes longer for the cells to open its doors to glucose resulting in higher amounts of insulin needing to be secreted. Secondary messengers acts to repair the doorbell so that the cell doors open in a timely response to glucose, resulting in less insulin needing to be secreted.

It has been suggested that women with PCOS have a problem converting myo into DCI (myo inositol gets converted into DCI when needed to maintain a 40:1 ratio in tissues). Supplementing with too much DCI (over 600 mg or more) was actually shown to negatively affect egg quality. That’s why it’s now recommended that women with PCOS supplement with both myo and DCI in a 40:1 ratio, that mimics the body’s natural physiological levels. We recommend Ovasitol, which is a tasteless powder you can put into your favorite beverage.

 

How Does Inositol Compare With Metformin?

Metformin has always been the go-to drug of choice for women with PCOS. The majority of women with PCOS have insulin resistance, a precursor to type 2 diabetes. Doctors figured the most popular and well-studied diabetes drug, metformin, can help PCOS too. And it does! Metformin can reduce insulin levels and perhaps reduce the risk for type 2 diabetes. Metformin can improve the regularity of some women’s menstrual cycles, helping them to conceive.

Metformin works to decrease your body’s production of glucose. In contrast, inositol works right at the cell wall to open its doors to glucose.

Since inositols are showing great results in women with PCOS (again, women with PCOS may have a defect in their ability to use inositol which could explain why so many women have insulin resistance in the first place), it’s being studied more and compared to metformin. So far (although more studies are needed), the results are in inositol’s favor.

The most recent study out this year, 128 women with PCOS took 1500 mg metformin or myo + d-chiro inositol (in a 40:1 ratio) daily for 3 months. The results: Myo + DCI showed significantly better results in weight reduction, ovulation, and pregnancy rates (46.7% vs. 11.2%) than metformin.

In a previous randomized controlled trial, 120 PCOS women trying to conceive took 1500 mg metformin vs 4 g myo + 400 mcg folic acid daily. Their results: women who took myo inositol had a better ovulation (65% vs. 50%) and pregnancy rate (30% vs. 18%) compared with the women who took metformin.

Both these studies show encouraging news for inositol being a promising first-line treatment for helping women with PCOS conceive and reduce insulin. Inositol is a good for those who can’t tolerate the side effects of metformin (inositol can also be taken with metformin for those who do tolerate it).

Personally, I saw and continue to experience, great results taking a daily combination of myo and DCI. I was skeptical at first, but given the large amount of research I discovered about inositol while writing the supplements chapter in PCOS: The Dietitian’s Guide, I figured it was worth a try. I am so glad I did!Dietitians Guide 3D

I’ve been on metformin for years and it has slightly helped to reduce my risk for type 2 diabetes by keeping my HA1C (a measure of how well glucose has been controlled over the past 3 months), stable in optimal ranges. When I first started inositol, my HA1C was 5.4% (pre-diabetes is diagnosed when HA1C reaches 5.7% or higher). After 3 months of taking inositol, my HA1C dropped to 5.1%. Six months later it went down to 4.9%. Nothing else changed. I (as well as my physician) were shocked. Metformin never lowered my HA1C like that for me. I continue to take both metformin and inositol and my HA1C continues to be stable around 5%.

My patients who take a combination of myo and DCI see a reduction in cravings, less hunger, and some get their periods back and more regular within a month (3 months of use is recommended for full effects). Typical dosage of Ovasitol is 2 packets each day (4 grams myo inositol total) in two divided doses. We recommend taking ovasitol with meals for maximum benefits. Ovasitol is well tolerated. As always, consult with your doctor prior to use. Only take inositol or any dietary supplement while under the supervision of a health care provider.

Tell us! What benefits have you seen by taking inositol?

Sources:
Hamid A et al. Evidence-Based Women’s Health Journal. 2015;5(3):93–98.
Raffone E, et al. Gynecol Endocrinol. 2010;26(4):275-80.

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Comments (38)
  • Caroline

    October 28, 2015 at 3:09 pm

    Hi, I’m wondering if you have any thoughts about Pioglitazone and PCOS? I recently switched from Metformin to Pioglitazone for my IR.

  • Shiri Morgan

    October 29, 2015 at 3:10 pm

    So interesting…will definitely start to recommend to my PCOS patients! My question is, does it have the same insulin sensitizing effect on those without PCOS? Those with type 2 diabetes and prediabetes?

  • Angela Grassi

    November 2, 2015 at 3:11 pm

    We don’t know yet how inositol works for those without PCOS. Women with PCOS have an intrinsci insulin resistance that is different from those with type 2 diabetes or obesity. Since it can reduce Ha1C levels, it’s worth trying it.

  • Lisa Amick

    November 3, 2015 at 3:12 pm

    Several years ago after reading articles about Inositol, I purchased and tried D=Chiro-Inositol by Chiral Balance. It was very expensive and after my initial 3 month trial, I didn’t see any positive changes from using it. Their site recommended longer use was possibly required to see results, but I wasn’t willing to put out that much money again. Earlier this summer I began reading articles from PCOS Nutrition Center and came across an article regarding Inositol supplements. I had already begun using an over the counter Niacin supplement by Radiance from CVS earlier in the year, which had helped me lose 10 lbs. Seeing results I was more open to trying further Inositol supplements and the explanation of the effectiveness of the Ovasitol brand made sense. Since using this brand, I’ve been able to drop another 10+ lbs. I’m at the lowest weight I’ve been in over 20yrs, since I had my oldest child. I’m still very much overweight, but to me it’s the most amazing thing! I’ve also had my yearly checkup and through the use of Inositol supplements, I’ve lowered my HAIC and my cholesterol levels, which are well within normal limits. Last year at my annual physical, my cholesterol was elevated and my physician wanted me to consider taking a cholesterol lowering medication, which I declined. I knew/know that my cholesterol is directly related to my PCOS and how well I can keep my PCOS in check. I’m constantly looking for new possible holistic treatments in addition to my metformin preion. I’ve had to manage my own treatment of my PCOS, because the only treatment ever suggested to me by any physician was metformin. Thru the years by reading various articles, I’ve added multiple supplements to my regimen. I’ve also diagnosed myself with low vitamin D and B12 levels, which I had confirmed by blood tests that my physician ordered. Thank goodness we live in a day and age of the internet, where we have the opportunity to research for ourselves, because without it, I would not be able to care for myself! Unfortunately, due to the lack of knowledge and concern in the medical field to diagnose and treat PCOS, you have to be your own patient advocate!

  • karen

    February 18, 2016 at 3:22 pm

    Hi, I’m just trying to learn about PCOS,being recently diagnosed…I was just wondering if I currently don’t have excessive hair growth and weight gain, will I stay this way or get new symptoms as time goes on?

  • Angela Grassi

    February 18, 2016 at 3:29 pm

    Hi Karen,
    thanks for your comment. If you don’t already have symptoms, your chances are lower of having them when your older. In general though, PCOS symptoms tend to get worse with age if PCOS is not well managed.

    Hope this helps!

  • My

    March 7, 2016 at 3:46 am

    Really helpful fpr me, i’m struggling daily to keep off the sugar. I try to exchange candy with healthier options like sweet vegetables and fruit. Also working on cutting out dairy and gluten. Thanks for an awesome page!
    My

  • joss Williams

    September 10, 2016 at 3:00 pm

    i was diagnosed pcos at 20 i am now 50 Type 2 diabetic will myo inosital help me? thanks
    j williams

  • Awais Siddiqui

    September 18, 2016 at 7:50 am

    Thanks for great notes.My question is.can someone intake Myo inositol along with metformin.

  • Angelica

    October 10, 2016 at 11:47 pm

    Hi, Ive also purchase Pregnatude can I use along with Metformin or discontinue the Metformin?Ive had two treatments for ovulation with insemination and no luck

  • Angela Grassi

    October 25, 2016 at 7:39 am

    You can use it with metformin, although we recommend Ovasitol which doesn’t contain folic acid (up to 60% of women don’t metabolize it) and has the ideal 40:1 ratio of myo and dci. Ovasitol is cheaper than pregnitude as well.

  • Marie

    November 19, 2016 at 8:27 am

    I have PCOS and my fertility doctor told me about Ovasitol because I was not interested in starting Metformin. Unfortunately I only started drinking it a week before conception, so I can’t say if it had anything to do with us being able to become pregnant. I had started a grain and dairy free diet a few weeks before, so I actually credit that with conception rather than Ovasitol, although I can’t be positive. I took this suppliment twice daily all the way up until week 24 of my pregnancy, My insulin resistance and blood sugar was measured before conception, and sugars came back normal, insulin came back high, so I know I was insulin resistant to begin with. I was diagnosed with gestational diabetes at week 12, and have struggled with my numbers ever since, even while taking Ovasitol religiously and eating a better diet. I saw no change in my blood sugars. I was still bouncing between mid 90s and low 100s for my fasting sugars and getting into the 120s-130s post meals regardless. A few days after I stopped taking Ovasitol, I started eating 1 tablespoon raw virgin unrefined coconut oil each day. It has been a few weeks since I made this change, and since then my fasting numbers have dropped to mid 80s to low 90s every morning, while post meal numbers continue to improve. I can’t say that this will continue to be a solution, since I know hormones will change the closer to our due date, but in my case, I really haven’t seen any benifit from taking Ovasitol.

  • Trudy

    January 28, 2017 at 10:18 pm

    The picture shown says availble in the US, is this available in any other countries yet? Im in australia. I think I will ask my gp when i go next im on metformin and a few other things. 3 months in i havent seen much improvement still no period or weight loss. My appetite has supressed though i find im eating less which is great

  • Angela Grassi

    January 30, 2017 at 8:51 am

    Sorry, we only ship to customers in the US and Canada.

  • Katrina

    February 15, 2017 at 12:38 pm

    Hi, I was diagnosed with pcos when I was 16 and was on and off the pill for years. At 30 I decided I wanted a baby and stopped all contraception and was able to get pregnant within 10 days. I am now 41. I have been on metformin for years and have regular periods and I am ovulating. My husband and I are not really trying for a baby but not not trying for a baby. I have just started inositol in the hopes that I can become pregnant hopefully soon. Has anyone had luck with being on inositol and metformin or is it better to just take one?

  • Kristen Finnell

    February 26, 2017 at 9:27 am

    Hello,

    I just want to post about my personal experience with Ovasitol because I am so grateful to have found out about its benefits when I did! I was diagnosed with PCOS when I was 18 years old, and I was on birth control for about 10 years after that. I was married in 2015 and stopped taking birth control in July 2015. After that, my cycles were completely unpredictable, ranging from 40-90 days between periods. I tried metformin, but I had terrible stomach upset and still did not have consist cycles, so I gave up after about 5 1/2 months. I heard about Ovasitol from reading blog posts and decided to give it a try. I began taking Ovasitol and prenatal vitamins daily in August 2016. I FINALLY had some consistency in cycles after about 2 months on the supplement. My cycles improved to about 40-45 days, and I just felt better overall! I began tracking my temperatures in November 2016, and after our FIRST attempt my husband and I conceived! I truly believe this has everything to do with Ovasitol and my own diligence to understand my body and PCOS. I am amazed and beyond thankful for this product!

    I believe everyone with the diagnosis of PCOS should give it a try! It is a breakthrough treatment, and it is unfortunate that it is not more well-known at this point.

    Kristen F.

  • Angela Grassi

    February 26, 2017 at 1:46 pm

    Fantastic Kristen! We are so happy for you! Best wishes for a healthy pregnancy!

  • Amy

    March 14, 2017 at 12:12 pm

    Does it help with weight loss?

  • Angela Grassi

    March 14, 2017 at 12:14 pm

    Amy, there are some studies that show inositol can result in weight loss and decreases to waist circumference but it’s not recommended as a weight loss supplement.

  • GOLO Review: Is it Really All it Claims to Be? | Aboutube.com

    April 13, 2017 at 6:14 am

    […] Inositol is a substance similar to a vitamin found in many plants and animals, but can also be produced artificially. The substance is connected to insulin sensitivity and may help improve the body’s response to insulin. Inositol helps improve cell’s reactions to insulin, meaning they respond more quickly to glucose in the blood. (10,11) […]

  • Debi

    May 4, 2017 at 7:50 pm

    Hello. Would love to try this. Is it safe/OTC? Any known side effects? I will discuss it with my endocrinologist, as well. Thank you

  • Angela Grassi

    May 5, 2017 at 11:29 am

    Ovasitol is well tolerated!

  • Hayley Ninnes

    May 29, 2017 at 2:26 pm

    Hello,

    Having been diagnosed with PCOS at 17 (I’m now 32) it frustrates me to no end that I have only been prescribed the OCP, Metformin or Aldactone. This looks very promising to me!
    I am blessed to have three children and I’m not, nor have I ever been overweight. But, I have excess hair on my face + have had acne since I was 11. Will this help?

    Thanks,

    Hayley

  • Angela Grassi

    May 30, 2017 at 9:26 am

    Yes, inositol like in Ovasitol has been shown to reduce acne and lower testosterone. Worth a try!

  • Rashemah Quinn

    June 9, 2017 at 10:58 am

    Hello my name is Quinn
    I’m 36 years old and I’m pre menstrual trying to reverse the curse
    My doctor have me on 1000mg of metformin ive been taking since February 15th,2017 I’ve had a period in March and April, but no period in May. It’s now June, I purchased inositol to go with my metformin and my breast are sore from time to time
    Should I take them together
    I’m so desperate for a bundle of joy
    Please help

  • Angela Grassi

    June 9, 2017 at 2:13 pm

    Yes, you can take ovasitol and metformin together. Best of luck!

  • Rita

    June 14, 2017 at 4:09 pm

    Hi, I took An Italian product That got these ingredients:
    Maltodestrine, Myo-Inositolo, Ossido di Magnesio, Acidificante: Acido Citrico, Aroma, Edulcorante: Sucralosio, Vitamina B3 (Nicotinamide), Ossido di Zinco, Vitamina D3 (Colecalciferolo), Agente antiagglomerante: Biossido di silice, Vitamina B5 (Calcio D-Pantotenato), Vitamina B12 0,1% (Cianocobalamina), Vitamina B2 (Riboflavina), Vitamina B6 (Piridossina Cloridrato), Vitamina B1 (Tiamina Cloridrato), Acido Folico (Acido Pteroil-monoglutammico), Selenito di Sodio.

    It contains myo-inositol … I’m on metformin for several years now and when I started to get this product changes my menstrual cycle completely!

    Can myo-inositol act differently on other persons?

    Thks

  • Rita

    June 14, 2017 at 4:12 pm

    Ps I would like to try this product but I’m afraid that my cycle will change again …

  • Angela Grassi

    June 20, 2017 at 3:46 pm

    Rita, most women see a positive change in their cycle. Worth a try!

  • pepG

    June 27, 2017 at 8:30 pm

    My experience with Ovasitol has been worse than metformin. With metformin I had some nausea & diarrhea when i first started & as I titrated myself to the prescribed dose of 1500mg but it only lasted a day or two. afterwards titration was over I had no issues. I thought I’d give ovasitol a try since most online pcos sites rave about it & there were “no side effects.” Wrong! i had worse bloating of my life,smelly gas, cramps, headaches, & horrible diarrhea. Supplements are not regulated & these people are marketing geniuses. I will stick with my metformin over ovasitol any day. It helped me ovulate & I don’t have to worry about sharting on my partner while it was babymaking time & I feel sexier when I don’t feel like a bloated whale 24/7.

  • Angela Grassi

    June 29, 2017 at 8:30 am

    We’re sorry you experienced side effects from Ovasitol. Most people do tolerate it well with minimal or no side effects.

  • Hollie

    July 16, 2017 at 1:53 pm

    Hi, I just wanted to clarify whether I can take Inositol as well as the Metformin? I can only tolerate 500mg Metformin a day.

  • Angela Grassi

    July 26, 2017 at 8:13 am

    Yes, you can take both together.

  • Karly

    August 7, 2017 at 10:39 pm

    Hi,
    I am just learning about the significance of supplements in my (long) journey TTC. Ovasitol does sound like a promising alternative to Clomid/Metformin. Can it be taken in conjunction with some other supplements I’ve been reading about (Tribulus, Vitex, Conceptions Tea, etc.), or should it be taken alone? The information out there is overwhelming, and I don’t want to end up doing more harm than good! Any insight you can share would be much appreciated.

  • Angela Grassi

    August 8, 2017 at 9:20 am

    Ye, you can take Ovasitol with other supplements. The inositol in Ovasitol has good research. Those other supplements not so much. You may want to start with Ovasitol and see how you do and how your body responds before starting the others.

  • Maus

    August 12, 2017 at 2:52 pm

    Hi, I would just like to share my experience with pcos and inositol:

    So I havent had a period in 10 months. Since 4 months I’ve been taking inositol (more or less 4grams a day, 2gr in morning and 2 gr before sleep, both on a empty stomach).Today I’ve had my first period!!! And it’s a real one (not just some brown discard). For real there were times I thought it might never come back.
    Im 25 years old, not overweight at all, have a healthy lifestyle and diet, been studying (and using) supplements for years and really have no clue where it came from. ..
    Some other supplements I took along were: B vitamin complex, flaxseed, zinc, magnesium and diatomaceous earth. I started doing yoga everyday about 4 months ago and did a full parasite cleanse some weeks ago, don’t know if that has anything to do with it though.
    Anyway I wanted to let you know because am absolutely sure it was the inositol that did the the trick. I’m one of those few who’s not interested in having a baby or anything and also didn’t fit the criteria of “pcos patient” (only had few of the symptoms ). Maybe I just had to connect more with my female side and I”ll keep on working on that.

    Good luck to you all, everyone has the capacity to heal themselves! !

  • Janelle

    August 22, 2017 at 12:09 pm

    Hi so I was diagnosed with pcos over 10 years ago and have been ttc for just over 8 years. No births, no losses and I’m just now taking control over my weight. I’m 31 and I’m determined to lose 100lbs. I have 1000mg myo inositol pills and I’m trying to figure out what the difference between all the other inositol supplements are. It seems like all the research I do takes me no where. Ive always been irregular and never know if or when I ovulate so not only am I wanting to take myo inositol for that but to lose weight. Any advice or suggestions appreciated.

  • Angela Grassi

    August 23, 2017 at 11:29 am

    Hi Janelle,
    A combination of Myo to D-chiro inositol in a 40:1 ratio can help regulate cycles, promote ovulation, and reduce insulin. We recommend Ovasitol which has this ratio. Here are some articles about it. For best results, take 2 grams of myo (or one packet of Ovasitol) twice a day with food.

    http://www.pcosnutrition.com/inositol/

    http://www.pcosnutrition.com/combination-of-myo-inositol-and-d-chiro-inositol-for-pcos/

    http://www.pcosnutrition.com/introducing-ovasitol-the-first-combined-myo-and-d-chiro-inositol-supplement-in-the-u-s/

    Let me know if I can answer any questions for you!
    Angela Grassi, MS, RDN, LDN

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