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. Eur Rev Med Pharmacol Sci, 2019. 23(5): p. 2293-2301. Polycystic ovary syndrome (PCOS) is a condition that causes hormone imbalances in women, which may lead to irregular periods and infertility. Weight gain, high blood sugar and undesirable cholesterol and triglyceride levels are also concerns with PCOS ( 16). R.Z., et al., Risk factors of vitamin B(12) deficiency in patients receiving metformin. Arch Intern Med, 2006. 166(18): p. 1975-9. Large doses of nicotinic acid can raise blood glucose levels by causing or aggravating insulin resistance and increasing hepatic production of glucose [ 43]. Some studies have found that nicotinic acid doses of 1.5 g/day or more are most likely to increase blood glucose levels in individuals with or without diabetes [ 38]. People who take any antidiabetes medications should have their blood glucose levels monitored if they take high-dose nicotinic acid supplements concomitantly because they might require dose adjustments [ 43]. Niacin and Healthful Diets

In addition, it’s unclear whether inositol supplements are safe for long-term use. In most studies, inositol supplements were only taken for a year or less. For blood sugar control in gestational diabetes: 2 grams of MYO and 400 mcg of folic acid twice daily during pregnancy ( 29, 30, 31). There are two main forms of inositol used in supplements, namely myo-inositol (MYO) and D-chiro-inositol (DCI).The Coronary Drug Project Research Group. Clofibrate and niacin in coronary heart disease. JAMA 1975;231:360-81. [ PubMed abstract] X., et al., Inositol supplement improves clinical pregnancy rate in infertile women undergoing ovulation induction for ICSI or IVF-ET. Medicine (Baltimore), 2017. 96(49): p. e8842. Phytic acid is the main source of dietary inositol. Some of the best high-inositol foods for women with PCOS include [ 7]:

Levine J, Barak Y, Gonzalves M, Szor H, Elizur A, Kofman O, Blemaker RH. Double-blind, controlled trial of inositol treatment of depression. Am J Psychiatry. 1995;152(5):792-794. doi:10.1176/ajp.152.5.792 Panchbhai A, Char B, Khara AS (2017) The ALDH7 promoter of Acacia nilotica L is a moisture stress inducible promoter. Plant Gene 10:1–7 Combination products like Ovasitol are safe to take during pregnancy and breastfeeding. There are no expected side effects. Take my PCOS inositol quiz to find out if a 40:1 ratio is best for you. 10. Ovasitol is the Best 40:1 Ratio Brand for PCOS Kulkarni M, Soolanayakanahally R, Ogawa S, Uga Y, Selvaraj MG, Kagale S (2017) Drought response in wheat: key genes and regulatory mechanisms controlling root system architecture and transpiration efficiency. Front Chem 5:106F., et al., Short-term effects of metformin and myo-inositol in women with polycystic ovarian syndrome (PCOS): a meta-analysis of randomized clinical trials. Gynecol Endocrinol, 2019. 35(3): p. 198-206.

Unfer V, Facchinetti F, Orrù B, Giordani B, Nestler J. Myo-inositol effects in women with PCOS: a meta-analysis of randomized controlled trials. Endocr Connect. 2017;6(8):647-658. doi:10.1530/EC-17-0243 Inositol also is a key component of cell membrane phospholipids in the form of inositol triphosphate (IP3) playing a pivotal role in the G‐protein‐dependent pathways. Keenan JM. Wax-matrix extended-release niacin vs inositol hexanicotinate: A comparison of wax-matrix, extended-release niacin to inositol hexanicotinate “no-flush” niacin in persons with mild to moderate dyslipidemia. Journal of Clinical Lipidology 2013;7:14-23. [ PubMed abstract]Alok A, Tiwari S, Tuli R (2019) A bidirectional promoter from Papaya leaf crumple virus functions in both monocot and dicot plants. Physiol Mol Plant Pathol 108:101423 V.R., et al., Long-term Metformin Use and Vitamin B12 Deficiency in the Diabetes Prevention Program Outcomes Study. J Clin Endocrinol Metab, 2016. 101(4): p. 1754-61. Even when taken in very high doses of 3–4 g, niacin is almost completely absorbed. Once absorbed, physiologic amounts of niacin are metabolized to NAD. Some excess niacin is taken up by red blood cells to form a circulating reserve pool. The liver methylates any remaining excess to N1-methyl-nicotinamide, N1-methyl-2-pyridone-5-carboxamide, and other pyridone oxidation products, which are then excreted in the urine. Unmetabolized nicotinic acid and nicotinamide might be present in the urine as well when niacin intakes are very high.

It’s important to be wary of products that include sweeteners, vitamins, and other ingredients. The addition of these other ingredients amounts to a “marketing maneuver” and may inhibit gut absorption [ 53]. Additionally, raised glucose levels lower myoinositol levels in a person’s tissues. The body breaks down the myoinositol faster, and the kidneys eliminate it faster, creating a vicious cycle. Homrich MS, Wiebke-Strohm B, Weber RLM, Bodanese-Zanettini MH (2012) Soybean genetic transformation: a valuable tool for the functional study of genes and the production of agronomically improved plants. Genet Mol Biol 35:998–1010

This is a fact sheet intended for health professionals. For a general overview of Niacin, see our consumer fact sheet on Niacin. Introduction For polycystic ovary syndrome: 1.2 grams of DCI once daily, or 2 grams of MYO and 200 mcg of folic acid twice daily for 6 months ( 17, 20). decreasing male sex hormone levels and thereby reducing the severity of acne and excessive hair growth Shinozaki K, SekiMand Nanjo T (2007) Environmental stress responsive promoter. In: Google Patent. US 20070006348 A1. Issued Jan 4, 2007 But the best inositol supplement for PCOS contains both myo-inositol and D-chiro-inositol. Studies show that a mixture of 40 parts myo-inositol to 1-part D-chiro-inositol is more effective than other formulations [ 49]. 40:1 is the physiological ratio that these two inositol isomers are found in the body.