Evidence-based guides
for every aspect of PCOS
16 in-depth articles covering nutrition, diet, exercise, medications, supplements, and fertility — written against published clinical research, not generic advice or supplement marketing.
New to CalcPCOS? Start here.
If you're newly diagnosed or not sure where to begin, these three articles cover the foundations — understanding why PCOS affects metabolism, what drives insulin resistance, and which dietary approach has the strongest evidence.
Why Is Weight Loss So Hard With PCOS? (And What Actually Helps)
Insulin resistance, elevated androgens, cortisol dysregulation, and hormonal water retention — the mechanisms that make PCOS weight loss slower than standard calorie math predicts, and the four levers that actually move the needle.
What Is Insulin Resistance — And Do You Have It With PCOS?
HOMA-IR explained, the PCOS-androgen vicious cycle, why normal fasting glucose doesn't rule it out, the 10-symptom checklist, and what you can do about it — including diet, exercise, and supplementation options.
The Best Exercise for PCOS — What 19 Clinical Trials Actually Found
A 2025 Bayesian network meta-analysis of 19 RCTs ranked six exercise types for insulin resistance and testosterone outcomes. The results are counterintuitive — yoga ranked first on both measures, above resistance training and HIIT. Here's why, and what it means for your training.
Does HIIT Help or Hurt PCOS? What the Research Actually Says
HIIT improves insulin resistance — but layered on top of poor sleep, calorie restriction, and chronic stress, it can worsen PCOS hormonal markers. The honest answer on when HIIT helps, when it backfires, and how to structure it correctly.
How Much Exercise Do You Actually Need With PCOS?
The 2023 International PCOS Guideline recommends 150–300 minutes per week — but what does that mean in practice? Minimum effective doses by goal, three starter weekly plans by time availability, and the timeline for when results appear.
Metformin for PCOS — The Complete Guide
How Metformin works, realistic weight timelines by dose (500mg–2,500mg + XR), the 25% fasting insulin drop in week one, GI side effect management, B12 depletion (reclassified as "common" by MHRA in 2022), and what amplifies its effects.
Inositol for PCOS — Myo vs D-Chiro, the 40:1 Ratio, Dosing & Evidence
Myo-inositol and D-chiro-inositol work through different mechanisms — and the 40:1 ratio matters because PCOS inverts the normal ovarian MYO:DCI balance. The only supplement in the 2023 International PCOS Guideline. Full evidence table by outcome.
Vitamin D and PCOS — Why 84% Are Deficient and What to Do About It
Deficient in 84% of PCOS patients in a 2025 study. Directly affects insulin sensitivity, testosterone production, ovarian function, and IVF outcomes — not just bone health. Why 20 ng/mL is not enough for PCOS, and how to correct to the optimal 40–60 ng/mL range.
PCOS Supplements Ranked by Evidence — What Actually Works, What Doesn't
10 supplements ranked by clinical evidence strength — from inositol and vitamin D (strong) to berberine, NAC, omega-3s, CoQ10, magnesium, zinc, probiotics, and what to skip. Honest ratings against RCT data, not manufacturer claims. Three practical stacks by goal.
PCOS and Getting Pregnant — What You Actually Need to Know
The full fertility pathway — lifestyle changes, letrozole, Metformin, gonadotropins, and IVF — with realistic success rates for each. The OHSS risk picture for PCOS in 2026, nutritional preparation, and what PCOS pregnancy monitoring looks like.
How Weight Affects PCOS Fertility — The Evidence on BMI and Conception
Each 1 kg/m² BMI increase is associated with a 9% decrease in clinical pregnancy rate in PCOS IVF patients. A 5% weight reduction can restore spontaneous ovulation. The BAMBINI trial data, the lean PCOS picture, and when age means you can't wait for weight loss.
Letrozole vs Clomiphene for PCOS — Which Ovulation Induction Works Better?
A 2026 meta-analysis of 32 RCTs confirms letrozole: 27.5% vs 19.1% live birth rate, 93.2% vs 77.9% ovulation rate, 58% reduction in multiple pregnancy risk. Why clomiphene's anti-oestrogenic effect on the endometrium is the key mechanism behind letrozole's superiority.
Nutrition for IVF With PCOS — What to Eat Before and During Treatment
A 40% higher pregnancy rate for those following a fertility-focused diet. The 90-day folliculogenesis window, the ketogenic IVF finding for insulin-resistant PCOS, phase-by-phase guidance from prep through the 2WW, and the seven-supplement IVF checklist.
Put the articles into practice
Eight free PCOS calculators — calorie target, macros, TDEE, insulin resistance, weight loss timeline, body fat, fertility nutrition, and Metformin weight projection. No signup required.