Uncovering the Secrets of D-chiro- inositol - PCOS Diva
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Uncovering the Secrets of D-chiro- inositol

by Amy Medling, Founder of PCOS Diva

I have written about demystifying Myo-inositol, a natural supplement used to help manage PCOS symptoms. Now it is time to uncover the secrets of D-chiro-inositol (DCI).  If you have yet to hear of myo-inositol , you’ll want to read my past posts and certainly read about the recent positive PCOS inositol research being done by Dr.  Antonio Simone Lagana.

Dr. Lagana shines the light on DCI. His studies conclude that, “In our experience, both inositol isoforms are effective in improving ovarian function and metabolism of patients with PCOS, although myo-inositol shows the most marked effect on the metabolic profile, whereas DCI reduces more hyperandrogenism.” (1)

Like myo-inositol, DCI is a member of the B vitamin family.  It is not a drug, but rather a nutritional supplement.  DCI plays a part of healthy metabolism and the body makes it from D-pinitol (another form of inositol) and myo-inositol. Myo-inositol is essentially a precursor to DCI. D-pinitol is found in many fruits and vegetables and myo-inositol in found in meats. D-pinitol’s only role in the body is to be converted to myo-inositol and then to DCI. The human body can, in principle, make DCI from either D-pinitol or myo-inositol, but in practice, some people do not make enough DCI.  The thought is that women with PCOS may not be able to convert efficiently to DCI.  Low levels of DCI has been observed in women with impaired insulin sensitivity and PCOS. (2)

The  graphic below depicts how myo-inositol is converted to DCI.


DCI is used during insulin signal transduction, the body’s response to insulin. If DCI is deficient, insulin resistance can develop. There is evidence that women with PCOS do not make enough DCI and many women with PCOS are insulin resistant. This deficiency leads to too much testosterone and the symptoms of PCOS.


The primary function of DCI is not to provide energy. Its primary function is as part of an important small molecule used during insulin signal transduction, a chemical signal chain that tells our bodies how to dispose of sugar. These small molecules are often called, “secondary messengers”.

  Myo-inositol and DCI are indeed different molecules. They belong to two different signal cascades and regulate different biological processes. It is a biochemical twist of fate that a deficiency of DCI, itself a carbohydrate, can make it so hard to correctly metabolize sugars, our energy carbohydrates. DCI is not abundant in our diets. So our bodies have to make DCI. And if our PCOS bodies are not efficient at converting myo-inositol and D-pinitol, the chemical signal chain breaks down and leads to high blood sugar, high insulin levels, and high androgen levels. These conditions can lead to type II diabetes, PCOS, endometriosis, and other disorders.
1. DCI increases the action of insulin, and improves ovulatory function, decreases serum androgen, blood pressure and triglycerides (3)

Dr. John Nestler  is an early pioneer in studying DCI and women with PCOS.  In one  of his studies, he looked at 44 overweight women with PCOS  who were given a daily 1,200mg dose of DCI for six to eight weeks. During the course of the study, those who took DCI displayed significant improvements in insulin sensitivity, blood pressure, and triglyceride levels, as well as a marked decrease in serum testosterone levels. Moreover, 19 of 22 subjects who received DCI ovulated during the study period, compared to only 6 of 22 in the placebo group. Dr. Nestler concluded,“D-Chiro-inositol increases the action of insulin in patients with the polycystic ovary syndrome, thereby improving ovulatory function and decreasing serum androgen concentrations, blood pressure, and plasma triglyceride concentrations.” (Nestler 1999).

2. DCI decreases testosterone in women with PCOS (1, 4)

There are many women that contact me who have PCOS, but don’t have the weight issues and wonder how they should treat PCOS differently.   This study involved lean women with PCOS. Participants received 600 mg daily of DCI or a placebo for six to eight weeks. The DCI treated participants improved significantly, displaying a large decrease of 73% in testosterone levels versus no change in the placebo group. Women taking DCI also experienced reductions in insulin and triglyceride levels and blood pressure, whereas none of these changes were evident in the placebo group.Ovasitol for PCOS

3. DCI helps obese women with PCOS increase insulin sensitivity in particular, women who have diabetic relatives. (5)

This study evaluated DCI (500 mg daily for 12 weeks) on hormonal parameters and insulin sensitivity in a group of overweight/obese PCOS patients (body mass index; BMI > 26). After the treatment researchers concluded that  DCI  is effective in restoring better insulin sensitivity and  balanced hormones (in particular LH/FSH) in obese insulin resistant  women with PCOS. Researchers found that PCOS patients with diabetic relatives showed greater improvement after DCI treatment.

4. Combined therapy myo-inositol plus DCI is able to improve IVF outcomes. (6)

This study looked at the  combined therapy  of myo-inositol plus DCI treatment in egg quality. The study looked at PCOS women undergoing IVF-ET.  They  were treated with myo-inositol combined with DCI or DCI alone. “The data clearly showed that only the combined therapy was able to improve oocyte and embryo quality, as well as pregnancy rates, in PCOS women undergoing IVF-ET.”

5. Combined therapy myo-inositol plus DCI improves metabolic reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone. (7)

In this study, 50 overweight women with PCOS were enrolled and divided in two groups to receive combined therapy.  One group was treated with myo-inositol in combination with DCI and the other was treated with myo-inositol alone for a period of six months. The researchers concluded that, “the combined administration of myo-inositol and DCI should be considered as the first line approach in PCOS overweight patients, being able to reduce the metabolic and clinical alteration of PCOS and, therefore, reduce the risk of metabolic syndrome.”

Where to find DCI?

DCI isn’t as readily available as myo-inositol.  The DCI alone is available from Chiral Balance.  Their (DCI) is sourced from Spain and is extracted from carob pods and then converted and purified to pharmaceutical grade DCI. DCI is quite a bit more expensive than myo-inositol because it isn’t readily available from dietary sources. Myo-inositol can be sourced from wheat, corn or soy.

I use a combination myo-inositol/d-chiro inositol product called Ovasitol.  For more info on Ovasitol you can read this post.

If you are wondering if DCI is safe to use if you are pregnant or breastfeeding, it has never been evaluated in a clinical trial for its use or safety during pregnancy or while breastfeeding. However, DCI is a natural human metabolite; it is essential to metabolic processes all over your body; and there is no reason to believe that it may be harmful. If you decide to discontinue DCI, you should speak to your doctor about other ways to manage your insulin resistance. Women with PCOS are at a higher risk of developing gestational diabetes, and insulin resistance is an important factor in the outcome of the pregnancy.  It is best to make the decision whether to use DCI while pregnant and  breastfeeding in conjunction with your physician who can help weigh the benefits and risks. I will point out that there is a recent study involving women in their second trimester taking a combination of myo-inositol, DCI, folic acid, and manganese. It wasn’t looking at safety specifically, but rather efficacy. But, the researchers and their auditors all assume that these substances were safe for pregnant women to take, or else the study would not have been approved.

Please share your experience with DCI and/or myo-inositol in the comment section below.


(1)  Laganà AS, Borrielli I, Barbaro L, Pizzo A (2013) Myo-Inositol Vs D-Chiro- Inositol: preliminary data on the comparison between their effects on ovarian function and metabolic factors in women with PCOS. Proceedings of The World Congress on Building Consensus out of Controversies in Gynecology, Infertility and Perinatology (BCGIP-cogi) (Istanbul, Turkey, 30th May – 2nd June 2013).

(2) Low levels of DCI, and inositol phosphoglycans have been observed in individuals with impaired insulin sensitivity and PCOS (Susuki 1994, Jung 2005, Cheang 2008, Baillargeon 2010).

(3) Ovulatory and metabolic effects of D-chiro-inositol in polycystic ovary syndrome (1999) Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond Virginia.

(4) Effects of D-chiro-inositol in lean women with polycystic ovary syndrome (2002) Department of Medicine, Medical College of Virginia, Virginia Commonwealth University, Richmond Virginia.

(5) Modulatory role of D-chiro-inositol (DCI) on LH and insulin secretion in obese PCOS patients. Genazzani AD1, Santagni S, Rattighieri E, Chierchia E, Despini G, Marini G, Prati A, Simoncini T. http://www.ncbi.nlm.nih.gov/pubmed/24601829

(6)  Arch Gynecol Obstet. 2013 Dec;288(6):1405-11. doi: 10.1007/s00404-013-2855-3. Epub 2013 May 25. The combined therapy myo-inositol plus D-chiro-inositol, rather than D-chiro-inositol, is able to improve IVF outcomes: results from a randomized controlled trial. Colazingari S1, Treglia M, Najjar R, Bevilacqua A. http://www.ncbi.nlm.nih.gov/pubmed/23708322

(7)  Eur Rev Med Pharmacol Sci. 2012 May;16(5):575-81. The combined therapy with myo-inositol and D-chiro-inositol reduces the risk of metabolic disease in PCOS overweight patients compared to myo-inositol supplementation alone.Nordio M, Proietti .  http://www.ncbi.nlm.nih.gov/pubmed/22774396


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14 responses to “Uncovering the Secrets of D-chiro- inositol”

  1. I’ve had a terrible experience so far with Myo Inositol. My naturopath recommended I start at half the dose and work up to full tsp daily. I couldn’t stomach it – crazy bloating, stomach pains. I cut back to 1/4tsp of the powder and it seems to have controlled the basic issues, but I find it makes my smoothies have a crystal texture to them. like flaked glass almost.

    Not sure how normal this is – I’ve only been on it about 6 weeks. Going back to see the naturopath in about a week and a half….maybe the capsules are easier to take?

  2. I’ve heard that caffeine kills inositol… do you know if this is true? I’ve been taking myo for a year with good results — all while drinking coffee everyday. I just decided (after reading this article) to start DCI. I wonder if my current results on myo, and my future results with DCI would be even better if I gave up coffee? Thanks for your input in advance!! 🙂

  3. I do not see a problem with coffee (in moderation) and Myo-inositol. There are no studies which specifically links coffee to NTDs. There is one study which found a possible link to caffeine intake, but the authors included ALL sources of caffeine, including tea, chocolate, coffee, etc. It looks like there was a single 1997 study, done in mice, which demonstrated that myo-inositol might reduce the risk of “folate-resistant” NTDs, but nothing was done on humans.

  4. Hi. Love the site. i was just wondering what worked better for you – taking Ovasitol, or the combination of Chiral Balance’s d-chiro-inositol and Ovaboost ?

  5. I am going to try inositol and d pinitol. should they be taken at different parts of the day?? And if I weigh 118, how much of each would be a good starting place, please??

  6. I have PCOS and I’m also post-menopausal (48 yrs old). I take Spironolactone.
    What benefit, if any, would I receive from taking this??

  7. Hello, I have PCOS and my main symptoms are lack of a period, insulin resistance, hair thinning and falling out, and acne. I was on BC pills but I was getting a yeast infection every month on them. I want to regulate my cycle naturally. I have changed my diet and am looking to get ovasitol. However, would this work for me if I’m not trying to get pregnant? I just want to have a regular period and diminish the pcos symptoms. Right now I’m taking Biotin, Magnesium, Vitamin B12 and Vitamin D. Any suggestions would be appreciated!

  8. I take myo inositol 1000mgs with DCI 600mgs a day (I’m childfree BTW so pregnancy I could care less about), is this optimal for weight loss in combination with stripped down keto diet?

  9. I have mild pcos, with irregular monthly cycles, a little bit insulin resistance, oily skin, thinning hair and had a horrible experience with myo inositol with cramps and crazy bloating and decided to try out Chiral balance d chiro inositol and for the very first time i saw ovulation signs and big ones with plenty cervical mucus and none of the horrible cramps that myo gave me. I wonder why is this …i take 600 mg daily. Can i take it with maca harmony from femmenessence??