Inositol is the name of a glucose isomer that was initially classified as a B vitamin. The current state of scientific knowledge indicates that there is a relationship between its level and women’s intimate health, including – polycystic ovary syndrome. How does inositol work, what are its effects, and are there recommendations regarding its dosage? Learn more about this ingredient and its impact on your health.
Contents
The role of inositol in treating PCOS
Polycystic ovary syndrome, or PCOS for short, is a disease unit encompassing a range of symptoms related to women’s reproductive health. As a result, several to even a dozen cysts appear on the ovaries, disrupting the proper functioning of the reproductive organs. The syndrome is still insufficiently researched to unequivocally determine its causes. It is currently considered an endocrinological (hormonal) condition with a genetic basis, but requiring an activating factor for the genes (the so-called trigger factor). Coexisting diseases that disrupt the endocrine system, including insulin resistance and diabetes, an improper lifestyle, excessive weight, etc., can contribute to gene activation and the development of PCOS.
PCOS is characterized by:
- irregular, often painful periods,
- reduced fertility resulting from irregular ovulation,
- hormonal imbalances – excessive production of androgenic hormones, resulting in, among other things, excessive hair growth or, conversely, male-pattern baldness.
Treatment for polycystic ovary syndrome currently relies primarily on alleviating its symptoms. One of the ingredients used for this purpose is inositol.
Inositol occurs in several forms in the human body, but myo-inositol (MYO) and D-chiro-inositol (DCI) are primarily important for reproductive health. Inositol plays several roles:
- it is a structural component – found, for example, in the cell membrane, but also in body fluids,
- it participates in the process of phospholipid metabolism that occurs during cell activation – this process is responsible for their ability to receive and transmit nerve impulses,
- it affects the levels of neurotransmitters such as serotonin – our mental health, among other things, depends on the ability to receive them,
- it participates in hormone synthesis,
- it supports lipid metabolism and carbohydrate metabolism.
In polycystic ovary syndrome, there is a disruption in the synthesis of hormones responsible for the proper functioning of the reproductive system, and metabolic disorders often appear, which then intensify endocrinological problems. Inositol is therefore an ingredient with the potential to regulate two key aspects of PCOS.
Myo-inositol and hormonal balance
Myo-inositol demonstrates the ability to regulate hormone production, but also to activate cells, making them more susceptible to their influence. This means that this component regulates the endocrine system in two ways:
- it reduces the risk of resistance, e.g., insulin resistance, by stimulating cells to react more effectively to hormones,
- it regulates the hormone production itself by the appropriate organs.
The current state of research suggests that by reducing insulin resistance, myo-inositol allows for the regulation of the entire endocrine system, whose function is disrupted in PCOS. Patients using supplements with this ingredient showed a significantly faster reduction in endocrinological symptoms of polycystic ovary syndrome compared to patients receiving only hormonal contraception1. In the case of individuals undergoing infertility treatment related to PCOS, positive results of supplementation were also noted – lower doses of substances responsible for inducing ovulation were required, and the quality of collected oocytes also improved 2.
D-chiro-inositol and glucose metabolism
Although comparative studies have shown that myo-inositol supplementation in infertility and PCOS therapy yields better results than, for example, folic acid supplementation alone, combined therapy with myo-inositol and D-chiro-inositol (DCI) is also an object of researchers’ interest. This is the second inositol derivative naturally occurring in human body cells susceptible to glucose, mainly in blood, liver, and muscles. It is currently suspected that DCI is responsible for regulating glucose and lipid metabolism, which in turn increases the effectiveness of therapies aimed at reducing insulin resistance in PCOS. Studies in which patients received myo-inositol combined with D-chiro-inositol indicated that after the treatment, patients had an increased chance of spontaneous return of regular periods, and in addition, test results such as cholesterol also improved – the amount of LDL fraction decreased, while HDL increased. Glucose and insulin concentrations in patients’ plasma also decreased, which was not observed in the group receiving only myo-inositol3. From the above studies, it appears that DCI primarily plays a supportive role for myo-inositol in the treatment of conditions such as PCOS, but additionally supports lipid metabolism and body metabolism. Thanks to this, it can provide valuable support for patients who, in addition to polycystic ovary syndrome, also struggle with, for example, type 2 diabetes.
How does inositol affect PCOS symptoms?
It is estimated that up to 13% of women suffer from polycystic ovary syndrome, and irregular periods, being its symptom, are the most common reason for visiting a doctor and receiving a diagnosis. However, irregularity results from an disturbed hormonal balance. Along with polycystic ovary syndrome, insulin resistance appears in the body – it affects up to 80% of overweight or obese patients, but is also diagnosed in at least one-third (30-40%) of patients with normal weight and PCOS. Importantly, elevated insulin and glucose levels are recorded in patients’ plasma even when the results do not qualify them for an insulin resistance diagnosis 4. Reduced insulin sensitivity (hyperinsulinemia) goes hand in hand with the stimulation of insulin receptors on the ovaries, which provokes them to excessive production of androgens (hyperandrogenism). Too high a concentration of these hormones disrupts the natural ovulation cycle – the egg cell is not released from the Graafian follicle.
In this context, myo-inositol acts on the source of the problem – it reduces insulin production and simultaneously reduces insulin resistance in other organs. As a result, it reduces the stimulation of ovarian receptors that cause hyperandrogenism, allowing for the restoration of balance between sex hormones in the body. Importantly, this effect was also recorded in the case of combined treatment. When patients took hormonal contraception, which supplied progesterone to the body, and combined it with myo-inositol, the regulation of androgenic hormone concentrations was faster recorded in their blood plasma along with an improvement in the body’s lipid metabolism, compared to women taking only contraception 5.
Efficacy of inositol in scientific studies
The spontaneous return of regular menstruation is noted as one of the main effects of myo-inositol supplementation; this result was obtained in studies where women took only myo-inositol with folic acid, as well as those where myo-inositol was combined with D-chiro inositol. In this aspect, a study that showed the superiority of combined D-chiro-inositol and myo-inositol supplementation over the action of metformin, a basic drug administered in the therapy of menstrual disorders and infertility in polycystic ovaries, is particularly interesting. After a three-month period of use, the group using inositols recorded a spontaneous return of regular menstruation at 46.7% compared to 13.6% in those using metformin6.
The second scientifically confirmed effect of myo-inositol supplementation is increased fertility. In the results of a study published in 2016, myo-inositol was compared with metformin. In the group administered myo-inositol, not only a higher spontaneous ovulation rate was recorded (65% compared to 50% in patients receiving metformin), but also a higher pregnancy rate (48.4%, compared to 36.6% with metformin), with both substances achieving a similar rate of spontaneous miscarriages (20.6% of pregnancies in the case of myo-inositol and 22.7% in the case of metformin)7.
This means that inositols are valuable support for every woman struggling with PCOS – regardless of whether she aims to conceive, or to regulate her menstrual cycle and reduce hormonal disorders.
Inositol usage
According to the recommendations of the Polish Gynecological Society, supplementation in the treatment of PCOS should be carried out in two daily doses of 2 g of the active substance myo-inositol 8. If the supplementation is prophylactic, the daily dose should not exceed 2000 mg/day. The supplement should be taken on an empty stomach or between meals.
Bibliography:
- Artur J Jakimiuk, Jacek Szamatowicz, The role of inositol deficiency in the pathophysiology of disorders occurring in polycystic ovary syndrome. Ginekologia Polska 85/2014.
- Kruk J. Jachimowicz K. Winiarska-Mieczan A. Inositol and its properties helpful in treating fertility disorders. Przemysł Spożywczy 75/2021, vol.7.
- Swora A., Borowik J., Brodowski W., et al., Inositol supplementation – known and possible applications||Inositol supplementation – known and possible applications, Journal of Education, Health and Sport 12/2022, vol. 9.
- Raffone E., Rizzo P., Benedetto V. Insulin sensitizer agents alone and in co-treatment with rFSH for ovulation induction I PCOS women. Gynecological Endocrinology 26/2010.
- Abdelhamid A.M.S., Madkour W.A.I., Borg T.F. Inositol versus metformin administration in PCOS patients: a case control study. Evidence Based Women’s Health Journal 2015.
- Position of the Expert Team of the Polish Gynecological Society on the use of preparations containing myo-inositol by patients with polycystic ovary syndrome (PCOS), Ginekologia Polska, no. 2/2014
- Minozzi M., Nordio M., Pajalich R. The Combined therapy myo-inositol plus D-Chiro-inositol, in a physiological ratio, reduces the cardiovascular risk by improving the lipid profile in PCOS patients. European Review for Medical and Pharmacological Sciences, 17/2013, vol.4.
- Minozzi M, Costantino D, Guaraldi C, Unfer V. The effect of a combination therapy with myoinositol and a combined oral contraceptive pill versus a combined oral contraceptive pill alone on metabolic, endocrine, and clinical parameters in polycystic ovary syndrome, Gynecological Endocrinology, 2011/27.