Inositol Dose Calculator for PCOS

Get an evidence-based starting dose for myo-inositol + D-chiro-inositol (40:1), spearmint tea pairing, and metformin overlap guidance, personalised by your PCOS phenotype and primary concern.

Carlomagno 2014, Nordio 2019, 2023 PCOS Guideline

Your evidence-based starting protocol

Based on your phenotype and primary concern

Inositol
--mg myo
--mg DCI
--
Spearmint tea
--cups / day
--

Your daily schedule

    Pair this with a PCOS-aware meal plan

    Inositol works faster when paired with low-GL meals and PCOS-supporting micronutrients. Get a personalised plan that fits your phenotype.

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    How this calculator works

    Three inputs map to a starting protocol grounded in clinical trials. None of your inputs leave your browser; everything runs locally in JavaScript.

    The 40:1 myo to DCI ratio

    Healthy ovarian tissue holds myo-inositol and D-chiro-inositol in roughly a 40:1 ratio. Carlomagno 2014 and Nordio 2019 both used this ratio (typically 4,000 mg myo + 100 mg DCI per day) and found significantly better ovulation and insulin response than DCI alone. Combination products like Inofolic Alpha and Ovasitol use this ratio for the same reason. Single-isomer DCI at high doses can actually impair ovulation (the DCI paradox), so we never recommend it alone.

    Phenotype adjustments

    Spearmint tea pairing

    Spearmint tea has an anti-androgen effect (Akdogan 2007, Grant 2010), most measurable on free testosterone and hirsutism scores. It does not move insulin meaningfully. If your primary concern is hirsutism or androgen-driven acne, you want spearmint as the bigger lever. If your primary concern is cycle or insulin, spearmint is a nice-to-have but inositol is doing the heavy lifting.

    Metformin overlap

    Both inositol and metformin improve insulin signaling but through different mechanisms (metformin reduces hepatic glucose output; inositol restores insulin receptor signaling). The 2017 Facchinetti meta-analysis found combined inositol + metformin produced larger improvements than either alone. There is no contraindication. If you are already on metformin, we still recommend the standard inositol dose; the meta-analysis effect was additive.

    This is not medical advice. Doses here are the most-studied starting points in published literature. Your endocrinologist or gynaecologist should sign off if you are pregnant, trying to conceive, on insulin, or taking any other prescription. Inositol has an excellent safety profile (no LD50 in any tested species) but interactions are best confirmed with someone who knows your full picture.

    Read more on PCOS supplements