It is well known that oocyte quality is the main factor determining chance of pregnancy and that poor quality is an obstacle for successful invitro fertilisation (IVF) results.
It has also become increasingly clear that the follicular microenvironment of a human oocyte is a crucial factor for its developmental competence. Through the years, many studies have been proposed to find strategies, drugs, or compounds such as antioxidant drugs and supplementation with vitamins or hormones able to improve oocyte quality and embryo quality.
Recently, studies on inositol supplementation during IVF have gained particular importance due to the effect of this molecule on reducing insulin resistance, improving ovarian function, oocyte quality, and embryo and pregnancy rates and reducing gonadotropin requirements during stimulation. Inositol and its isoform, especially myo-inositol, finds its application pre-treatment in polycystic ovary syndrome (PCOS) patients undergoing IVF cycles and, recently, also in all kinds of infertile patients such as poor responders
PCOS and Myo-inositol
Hyperinsulinemia due to insulin resistance occurs in up to 80% of women with PCOS. Studies have suggested that an impairment of the insulin pathway could be due to a defect in the inositol phospho-glycans (IPGs) second messenger. IPGs play a role in activating enzymes that control glucose metabolism. In people with PCOS, a defect in tissue availability or altered metabolism of inositol or IPGs mediators may contribute to insulin resistance. Previous studies have demonstrated that myo-inositol is able to restore spontaneous ovarian activity in PCOS women and consequently fertility in many of these cases.
People with PCOS requiring IVF
More than 60% of in vitro fertilization (IVF) cycles do not result in a pregnancy and poor oocyte quality is the main cause of fertilization failure in assisted reproductive techniques (ART). Therefore ART nowadays focus on obtaining high quality oocytes rather than high numbers of oocytes and embryos. In follicular fluids in humans, higher concentrations of myo-inositol represent a marker of good-quality oocytes. Clinical trials show that myo-inositol supplementation started three months before the onset of ovarian stimulation results in significant improvements in hormonal responses, reducing the inter- national unit (IU) of FSH needed to an optimal follicular development and estradiol levels at the day of ovulation trigger; this leads to a reduced risk of ovarian hyperstimulation syndrome (OHSS) and a lower number of cancelled cycles. Growing number of trials have shown that myo-inositol supplementation positively correlates with the number of high quality oocytes retrieved. This means a reduction in the number of degenerated and immature oocytes, with consequently increased quality of embryos produced after fertilization. That said, the studies that have been performed are relatively small and additional investigations on larger number is needed to study its full impact on stimulation and pregnancy outcomes in IVF procedures.
People without PCOS
Small studies suggest that myo-inositol supplementation in low responding patients results in an increase of the number of oocytes recovered in meiosis II and of the ovarian response to FSH. Hence, myo-inositol seems to be helpful in low responders undergoing IVF cycles.
Where can I get the drug ?
Myo-inositol can be ordered online or sourced in your local pharmacy. No script is needed. Myo-inositol is available as powder form in either a 150g or 300g powder. One metric teaspoon is equivalent to 3000mg of Myo-inositol. Recommended dose is 3000mg - 4000mg / day . The cost is approximately $37 for the 150g or $48 for the 300g. Fountain Health Food stock it .
Links for ordering online
Side effects and safety
The general consensus seems to be that myo-inositol is a safe supplement to take given no clinically relevant adverse effects have been found in several human studies that looked at doses of 4000 mg per day throughout pregnancy.
Lesoine B, Regidor PA. Prospective Randomized Study on the Influence of Myoinositol in PCOS Women Undergoing IVF in the Improvement of Oocyte Quality, Fertilization Rate, and Embryo Quality. Int J Endocrinol. 2016;2016:4378507. doi:10.1155/2016/4378507
Simi G, Genazzani AR, Obino ME, Papini F, Pinelli S, Cela V, Artini PG. Inositol and In Vitro Fertilization with Embryo Transfer. Int J Endocrinol. 2017;2017:5469409. doi: 10.1155/2017/5469409. Epub 2017 Feb 28. Erratum in: Int J Endocrinol. 2019 Apr 11;2019:8309405. PMID: 28348586; PMCID: PMC5350329.