Myo-inositol side effects are rare, and when they are experienced, they are minor in almost every case. Myo inositol is one of nine stereoisomers of the natural pseudovitamin carbohydrate Inositol.
Stereoisomers are 2 or more chemical compounds that have the same molecular makeup and are only different in terms of their 3-D spatial arrangement of atomic particles. Of the nine known stereoisomers of inositol, myo inositol is the one that is found most abundantly in nature.
All DNA-based nucleated organisms (eukaryotes) utilize myo inositol and its related stereoisomers for a multitude of brain, central nervous system, and body functions. The different forms of inositol are known to be associated with everything from healthy hair growth to mood enhancement to immune system boosting to the structure of our individual cells.
Using myo inositol supplements is considered to be safe since the body makes this compound naturally and we find it from many common food sources. However, there may be some mild Myo-inositol side effects based on individual sensitives as well as certain contraindications.



- Supports brain & liver health
- Involved in mood regulation & nerve signalling
- Improves insulin sensitivity for PCOS, fertility & weight loss
Myo Inositol Roles in the Body
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For the average human, between 2 and 3 grams of inositol are produced within the body (endogenously) every day. This happens mostly in the kidneys and the exact amount produced would be a result of ever-fluxing demands as determined by the brain.
The ISYNA1 gene encodes inositol-3-phosphate synthase 1 which is used to isomerise glucose-6-phosphate (G6P). This results in a phosphorylated form of myo inositol, myo-inositol phosphate-1.
Inositol monophosphatase (IMPase) is then used to dephosphorylate the myo-inositol phosphate-1, leaving the pure form of myo inositol left over.
There are a number of ways that myo-inositol works in the body. Inositol and its derivatives are involved in the following functions:
- Inositol is a polyol carbohydrate that is used to synthesize the phospholipid bilayers that envelop out cells and protect intracellular constituents like mitochondria, ribosomes, organelles and nuclei. It is integral in the formation and structural strength of all eukaryotic cells.
- Myo inositol is partially responsible for regulating cellular functions, including apoptosis (scheduled death), migration and more. Gene expression also relies on this compound.
- Major transmitters of nerve impulses like dopamine and serotonin rely on inositol as a secondary messenger. Inositol is required to open calcium channels on neuron membranes, accommodating signalling. Secondary messengers are used to complete neurotransmission, delivering information to the nuclei and other bodies within individual cells.
This compound also helps to transport fats throughout the body and in some cases shows positive effects for weight loss. Inositol is an effective fat emulsifier and can cause triglycerides and LDL (“bad”) cholesterol levels to drop and HDL (“good”) cholesterol levels to rise. Saturated fats and trans fats are more efficiently metabolized. This could be beneficial for the following medical conditions:
- Cardiovascular Disease
- Cancer
- Stroke
- Atherosclerosis
- Diabetes
- Hypertension
- Obesity
Other Myo Inositol Uses
Inositol derivatives are also under research for numerous other health conditions including depression, schizophrenia, autism, ADHD, psoriasis, panic disorder, hair growth, and more. Research studies have shown that inositol supplementation may be effective for improving the symptoms of Obsessive Compulsive Disorder (OCD) and Polycystic Ovary Syndrome (PCOS).
One crossover study tested diagnosed OCD patients on both 18 g of inositol for 6 weeks and then on placebo, to get an accurate personal comparison of scores on the Yale-Brown Compulsive Scale. It was found that patients had significant improvement taking inositol compared to when they took a placebo based on their scores. The trial, while robust in its methodology, was relatively small in its sample size (13 patients) and larger trials are needed to confirm these results.
Taking inositol for PCOS may help to improve or manage some serious complications of the syndrome. In research studies, taking inositol for PCOS has been seen to increase insulin sensitivity, lower elevated androgen levels (and improve androgenic side effects like acne and excessive body hair growth), decrease serum triglyceride levels, modestly decrease blood pressure, and induce ovulation.
The Natural Medicines database has rated Inositol as Possibly Effective for improving lithium-induced side effects, OCD, panic disorder, PCOS, and respiratory distress syndrome. While research has been promising, more large-scale double-blind placebo-controlled studies are still needed to confirm the results of smaller studies.
At this time, the FDA has not approved Inositol as a drug to prevent or treat any conditions, and Myo-inositol is available as a dietary supplement only.
Myo Inositol Side Effects
For all of the likely health benefits offered by myo inositol, there are very few side effects reported in clinical trials. The only myo-inositol side effects ever noted were mild, consisting of headaches, dizziness, nausea, and tiredness.
In 5% of users taking 12g per day, mild gastroinstestinal discomfort is noted. This is attributed to the digestion of the supplement as opposed to any specific effects from it. Dosages of up to 30g per day have been well tolerated, with only gastrointestinal side effects reported. Because of the safe track record of this nutrient, it is widely used today.
If you are considering myo inositol supplementation, you should consult with your doctor first. There are some cases where inositol supplements may not be recommended.
Pregnant and/or nursing women should not take any supplements without the express consent of their pediatricians. It is believed that inositol may cause uterine contractions due to its relationship with oxytocin, and therefore use in pregnant women is not recommended. While inositol is a natural component in breastmilk, there have been no studies on the effects of supplemental inositol in infants, and therefore use should only be done on your doctor’s recommendation.
Those who are scheduled for any type of surgery should discontinue myo inositol use at least 2 weeks before undergoing their surgical procedures. In some cases, over-supplementation may cause the symptoms of bipolar disorder to worsen.
How to Take Myo Inositol Powder and Capsules
Proper dosage depends on many different factors including age, weight, sex, and the reason for taking a supplement. Specific dosing amounts to avoid myo inositol side effects should always be discussed with your physician.
Myo inositol dosages will depend on the reason for using this supplement. In most cases, doses fall between 200-4,000mg, taken once per day in the morning. Higher dosages tend to be more effective, but you should speak to your doctor to determine appropriate use.
For some neurological conditions such as depression, panic attacks, and OCD, amounts of between 14-18g per day have been used under doctor supervision. Dosages this high are still considered to be well-tolerated, with few myo-inositol side effects reported.
- Gerli S, Papaleo E, Ferrari A, Di Renzo GC. Randomized, double blind placebo-controlled trial: effects of myo-inositol on ovarian function and metabolic factors in women with PCOS. Eur Rev Med Pharmacol Sci. 2007
- Shetty HU, Schapiro MB, Holloway HW, Rapoport SI. Polyol profiles in Down syndrome. myo-Inositol, specifically, is elevated in the cerebrospinal fluid. J Clin Invest. 1995
- Michell RH. Inositol derivatives: evolution and functions. Nat Rev Mol Cell Biol. 2008
- McGrath BM, McKay R, Dave S, Seres P, Weljie AM, Slupsky CM, Hanstock CC, Greenshaw AJ, Silverstone PH. Acute dextro-amphetamine administration does not alter brain myo-inositol levels in humans and animals: MRS investigations at 3 and 18.8 T. Neurosci Res. 2008
- D'Anna R, Scilipoti A, Giordano D, Caruso C, Cannata ML, Interdonato ML, Corrado F, Di Benedetto A. myo-Inositol supplementation and onset of gestational diabetes mellitus in pregnant women with a family history of type 2 diabetes: a prospective, randomized, placebo-controlled study. Diabetes Care. 2013
- Colazingari S, Treglia M, Najjar R, Bevilacqua A. 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. Arch Gynecol Obstet. 2013
- Kim H, McGrath BM, Silverstone PH. A review of the possible relevance of inositol and the phosphatidylinositol second messenger system (PI-cycle) to psychiatric disorders--focus on magnetic resonance spectroscopy (MRS) studies. Hum Psychopharmacol. 2005
Article last updated on: May 12th, 2018 by Nootriment