Fertility Hero Pure Myo-Inositol

PMOS stands for Polycystic Metabolic Ovarian Syndrome, the updated name for what has historically been called PCOS (Polycystic Ovary Syndrome). The name change reflects a growing clinical consensus that the condition is primarily a metabolic disorder driven by insulin resistance, rather than simply an ovarian condition. The underlying biology and the research base remain the same. If you have a PCOS diagnosis, PMOS is the same condition. You may still see PCOS used widely, including in the research we reference, as the terminology is still in transition.

Myo-inositol is a naturally occurring compound classified as a B-vitamin-like substance. It is found in foods including fruits, beans and grains, but the amounts achievable through diet are well below the 4g associated with clinical effects. It plays a central role in cell signalling, particularly in how cells respond to insulin, which is why it has been most studied in conditions involving insulin resistance, including PMOS (previously known as PCOS).

The clinical research on myo-inositol uses 4g per day consistently. Studies using lower doses have generally shown weaker or less consistent effects. Many products on the market provide 2g or less, below the level used in the research. We use the evidence-based dose.

The pharmacokinetics of myo-inositol favour divided dosing: blood levels are better maintained with two 2g doses than a single 4g dose. The majority of clinical studies also used divided dosing. Taking it once a day is better than not taking it, but twice daily is the protocol the research is based on.

Some products combine myo-inositol with d-chiro-inositol, often at a 40:1 ratio. The rationale is that d-chiro-inositol plays a role in insulin signalling alongside myo-inositol, and that supplementing both in a physiological ratio makes sense. This is a reasonable hypothesis, but the evidence is less clear than it might appear.

The body converts myo-inositol into d-chiro-inositol via an enzyme called epimerase, meaning that if you have adequate myo-inositol, your body can produce the d-chiro-inositol it needs. The 40:1 ratio that has become common in combined products was derived from plasma levels and has been widely adopted, but the research basis for this specific ratio is not as robust as is often implied. Critically, research looking at ratios with a higher proportion of d-chiro-inositol than 40:1, such as 20:1 or 10:1, has generally shown weaker or counterproductive effects, particularly in the ovarian environment where higher d-chiro-inositol concentrations are associated with impaired steroidogenesis. This suggests the direction of travel should be more myo-inositol, not more d-chiro-inositol.

The 40:1 ratio is a patented formulation, which adds cost without, in our view, adequate evidence of superiority. Our position is that the strongest, most consistent evidence is for myo-inositol at 4g per day. We would rather give you the evidence-based form that has the most research behind it than increase the cost to you without robust evidence of benefit.

No. Myo-inositol is relevant to any woman with signs of insulin resistance, including irregular cycles, elevated androgens and difficulty losing weight, regardless of a formal diagnosis. It is also used by women without PMOS (previously known as PCOS) who are preparing for IVF or egg freezing to support egg quality.

Yes, there is no overlap. Myo-inositol is not present in Fundamental Woman. The two products are designed to work together as part of a complete protocol.

Both are common excipients, manufacturing aids used to help powder flow through capsule-filling machinery. They are widely considered safe, but neither adds any nutritional value and we prefer to keep our formulations as clean as possible. Our capsules contain only myo-inositol and an HPMC shell.

Fertility Hero Myo-Inositol comes in a compostable laminate pouch, suitable for home composting depending on local conditions and facilities. We chose this format specifically to avoid single-use plastic, and because a pouch uses significantly less material than a bottle for the same number of capsules.

Yes, myo-inositol is not animal-derived and we use an HPMC capsule shell.

There is growing research on myo-inositol and sperm quality, including motility and DNA fragmentation. If your partner is interested in this area, myo-inositol can be taken alongside Fundamental Man and our CoQ10 as part of a complete male fertility protocol.