A trial pointed the other way from the ratio the market is built on
At five Spanish sites, 60 women with polycystic ovary syndrome took one of two blends. The arm on roughly eleven times more D-chiro-inositol reached live birth 55.2% of the time, against 14.8%.
What the study found
More D-chiro-inositol, not less, led to more live births
A double-blind trial at five Spanish sites gave 60 women with polycystic ovary syndrome, or PCOS, one of two blends. The arm on roughly eleven times more D-chiro-inositol reached live birth 55.2% of the time against 14.8% on the standard 40:1 formulation.
The caveat · Fertility-treatment patients only
These were women undergoing fertility treatment, so this describes a fertility-treatment add-on rather than everyday supplementation. Sixty were randomised and about 44 analysed, a thin base for a gap that wide. There was no plain myo-inositol arm, so it cannot say whether either blend beats myo-inositol on its own. Several of the authors are affiliated with a nutrition-sector company.
What we don't know
The 40:1 ratio the market is built on has been tested far less than the argument over it suggests. The only two trials comparing ratios head to head point opposite ways, and both sit at the lowest certainty rating.