Inositol
A supplement with the largest evidence base for PMOS, usually myo-inositol with a small share of d-chiro-inositol. Studied for insulin sensitivity and ovulation.
Inositol is a naturally occurring compound involved in how cells respond to insulin. As a supplement, it has the largest evidence base of any over-the-counter option for PMOS.
The most-studied form is myo-inositol combined with a small proportion of d-chiro-inositol, often in roughly a 40-to-1 ratio. Multiple randomised trials and meta-analyses report improvements in insulin sensitivity, androgen levels, and ovulation rates over three to six months in many users. The side-effect profile is favourable.
Inositol is available without a prescription in most places. It is not a guaranteed result for everyone, and response varies. Pregnancy and active conception are contexts where a clinician should be in the loop. As with the rest of the metabolic toolkit, it works best alongside the foundational steps, not instead of them.