Inositol and PCOS: reducing symptoms and improving fertility

Inositol is a naturally occurring organic compound found in the body. It is often described as a B vitamin. Myo-inositol is the most abundant isomer of inositol in mammals. It is commonly found in almost all tissues, particularly in the brain, blood, fat, kidneys, lungs, ovaries and testes, where it participates in several cellular pathways [2].

Inositols are mediators of important functions, including cellular energy metabolism, follicle maturation and cell motility. In particular, follicle maturation is a crucial process for fertility. Furthermore, proper cell motility is essential during embryogenesis processes, such as neural tube closure [3].

It also plays a crucial role in cell signalling, insulin regulation (reducing resistance) and lipid metabolism. It is also beneficial for menstrual balance and hormonal health. 

In people with PCOS, inositol helps improve insulin sensitivity, restore ovulation and reduce androgen levels, thereby helping to alleviate the symptoms of this condition. It is also beneficial for those who are trying to conceive. 

Inositol may help balance important chemicals in the brain, including those known to influence mood, such as serotonin and dopamine [4].

There are several forms of inositol, but the two main ones used in the context of PCOS are myo-inositol and D-chiro-inositol.

Myo-inositol

It is the most abundant form in the human body. It is involved in insulin regulation and hormonal signalling. 

Myo-inositol, as a mediator of insulin activity, is now considered a commonly administered therapeutic agent in the context of IVF to induce ovulation. As it contributes to the production of follicle-stimulating hormone (FSH). People with PCOS often have low FSH levels. This would in turn cause disruption to FSH signalling and a deterioration in oocyte development [5].

Studies have shown that myo-inositol supplementation may improve insulin sensitivity, restore ovulation and improve fertility in women with PCOS.

D-chiro-inositol

D-chiro-inositol is another important form, although present in smaller quantities. It is commonly detectable as a minor constituent in almost all tissues containing myo-inositol (MI) [6]. It plays a role in carbohydrate metabolism and the regulation of androgen levels. A combination of MI and D-chiro-inositol (DCI) in a ratio of 40:1 is often recommended to optimise therapeutic effects. 

However, caution is advised regarding DCI supplementation. Excess DCI in ovarian follicles may be potentially harmful in certain cases. It is therefore important not to supplement blindly, and especially not in high quantities [7].

A great deal of research has explored the efficacy of inositol in PCOS. These studies highlight its positive effects on metabolic disorders, the success of in vitro fertilisation (IVF) and oocyte development.

Inositol, PCOS and metabolic disorders

PCOS is often associated with metabolic disorders such as insulin resistance, obesity and type 2 diabetes. 

Inositol supplementation may lead to a reduction in triglyceride levels, total cholesterol and LDL cholesterol in those with metabolic conditions [8].

It may also help with weight loss. A meta-analysis suggests that inositol supplementation has a positive effect on BMI reduction [9].

In one study, they showed that myo-inositol administration improves the functioning of the reproductive axis in patients with PCOS by reducing hyperinsulinaemia, which affects LH hormone secretion. Moreover, the menstrual cycle was restored in all participants presenting with amenorrhoea or oligomenorrhoea [10]. 

One study notably showed that it was at least as effective as a metformin-based treatment [11].

Inositol, PCOS and hyperandrogenism

Hyperandrogenism is the characteristic sign of PCOS. It is a hormonal imbalance caused by the ovaries producing an excess of male hormones. This hormonal excess can generate various symptoms, including acne (particularly on the lower face) and hirsutism (excessive hair growth in unusual areas). 

One study looked at the effect of taking 4g of myo-inositol per day for 6 months. Its consumption considerably reduced hirsutism and hyperandrogenism and improved the abnormal metabolic profile of those with hirsutism [12].

Similarly, another study demonstrated this beneficial effect, with the additional finding of a reduction in acne [13]. 

Inositol, PCOS and cycle regulation

This molecule may also be beneficial for cycle balance. This has been demonstrated in several studies. 

In particular, one study looked at myo-inositol intake in 140 subfertile women with PCOS. Participants received 2 grams per day for six months. The results show a significant improvement in menstrual cyclicity and ovulation: after 6 months, 54% of women had regained regular cycles and 72% were ovulating [14].

Inositol, PCOS and oocyte quality

Oocyte quality is often impaired in cases of PCOS. Myo-inositol plays an essential role in oocyte maturation. Higher concentrations in human follicular fluid appear to play a role in follicular maturity and provide a marker of good-quality oocytes [15].

Research has shown that myo-inositol supplementation improves oocyte and embryo development. For example, one study showed that taking 4g per day led to better oocyte quality, with +6% of fertilised oocytes in particular. Moreover, this was also shown to be beneficial at the embryonic level, with +30.8% of grade I embryos. The researchers also observed, compared with those not taking it, a higher fertilisation rate of 58% [16]. 

Our food supplement to support conception Ovo+ is compatible with PCOS and inositol supplementation. It contains, in particular, Coenzyme Q10 and NAC, which are beneficial for oocyte quality. 

Inositol, PCOS and IVF success

Good oocyte development is a crucial factor in the success of IVF treatments. Studies have shown that myo-inositol supplementation improves oocyte development and also increases the chances of fertilisation. 

For example, one study revealed that myo-inositol administration increases clinical pregnancy rates, reduces the total dose of rFSH and shortens the duration of ovulation induction [17].

Furthermore, another study showed that in women both without and with PCOS who are undergoing IVF, myo-inositol supplementation prior to ovarian stimulation may have a positive effect on gonadotrophin use and duration, oocyte and embryo development, fertilisation and clinical pregnancy rates [18].

Based on our research across 16 studies on inositol supplementation for PCOS, over an average period of 3 months, we found the following benefits: 

Conventional treatments for PCOS include oral contraceptives, insulin-sensitising medications such as metformin, and surgical interventions in severe cases. However, these options and products may have side effects and are not suitable for all patients.

Inositol, as a natural supplement, offers an alternative with fewer adverse effects, whilst targeting the underlying causes of PCOS, such as insulin resistance and hormonal imbalance.

One study notably showed that it was at least as effective as metformin [29]. Another study showed that it appeared even more effective than metformin [30].

Inositol, particularly in the form of myo-inositol, is one of the promising dietary supplements for the management of pcos and pregnancy, and improve symptoms even outside of the conception window. In particular, at a dose of 4000 mg/day in 2 intakes, it is effective and safe for:

• Restoring ovulation and cycles
• Supporting the development of oocytes and embryos
• Increased chances of fertilisation and pregnancy
• Reducing the stimulation required (FSH, days, doses)
• Rebalancing hormonal profiles

It is recommended to consult a healthcare professional before starting any supplementation, in order to determine the appropriate dosage and ensure a personalised approach.