PCOS (Polycystic Ovary Syndrome) — NZ Condition Guide | KiwiMeds

What is PCOS?

Polycystic ovary syndrome (PCOS) is a common hormonal condition affecting people with ovaries, typically starting in the reproductive years. It involves irregular or infrequent periods, excess androgens (male hormones), and/or polycystic ovaries (ovaries with many small fluid-filled follicles visible on ultrasound). PCOS affects around 1 in 10 women of reproductive age in NZ and is one of the most common causes of fertility problems.

Symptoms

PCOS symptoms vary widely. Common symptoms include irregular, infrequent, or absent periods, difficulty getting pregnant, excessive hair growth on the face, chest, back or buttocks (hirsutism), oily skin and acne, thinning hair or hair loss from the scalp, weight gain (particularly around the abdomen), and mood changes including anxiety and depression. Not everyone with PCOS has all these symptoms.

Causes and Risk Factors

The exact cause of PCOS is not fully understood, but it involves hormonal imbalances — particularly elevated androgens (testosterone) and insulin resistance. Family history of PCOS increases risk. Insulin resistance (common in PCOS) means the body needs more insulin to maintain normal blood sugar, which in turn stimulates the ovaries to produce more androgens, worsening PCOS symptoms.

Diagnosis

PCOS is diagnosed using the Rotterdam criteria — a diagnosis is made when at least 2 of the following 3 features are present: irregular ovulation, elevated androgens (either on blood tests or by symptoms like hirsutism/acne), and polycystic ovaries on ultrasound. Other conditions that cause similar symptoms (thyroid disease, elevated prolactin, congenital adrenal hyperplasia) must be excluded first.

Treatment in New Zealand

PCOS treatment is tailored to your main concerns. For irregular periods and contraception, the combined oral contraceptive pill (OCP) is commonly used and is Pharmac-funded. For hirsutism, the OCP and anti-androgens (spironolactone) may be used. For fertility, clomifene or letrozole stimulates ovulation. For insulin resistance and blood sugar management, metformin is widely used off-label. Weight loss (even 5–10% of body weight) can significantly improve all aspects of PCOS. A low-GI diet and regular exercise are important lifestyle strategies.

NZ-Specific Information

PCOS NZ (pcos.org.nz) provides NZ-specific support and information. Fertility treatment (including IVF) is partially subsidised through the public health system in NZ for eligible patients — discuss with your GP or gynaecologist. A multidisciplinary approach (GP, dietitian, psychologist) often works best for PCOS management.

Frequently Asked Questions

Does PCOS affect fertility? Yes, PCOS is a common cause of anovulatory infertility (not ovulating), but many women with PCOS do conceive — sometimes with medication to induce ovulation. Does PCOS go away after menopause? Menstrual irregularity resolves after menopause, but metabolic features (insulin resistance, cardiovascular risk) may persist. Does the pill cure PCOS? No — it manages symptoms while you take it but does not treat the underlying condition.

Supplements That May Support Management

⚠️ Important: The supplements listed below have varying levels of clinical evidence. They are not a substitute for prescribed medications and should only be considered as adjunctive support under the guidance of a qualified healthcare professional. Always inform your GP or pharmacist before commencing any supplement, as interactions with prescribed medicines are possible.

• Inositol (Myo-Inositol and D-Chiro-Inositol, 40:1 ratio) — Inositol is the most evidence-based supplement for PCOS, with multiple randomised trials demonstrating improvements in insulin sensitivity, ovulation rates, menstrual regularity, and androgen levels. The 40:1 myo:D-chiro-inositol combination at 4000 mg:100 mg daily mirrors physiological tissue ratios.
• Vitamin D — Vitamin D deficiency is highly prevalent in PCOS and correlates with insulin resistance severity and menstrual irregularity. Supplementation (2000–4000 IU/day, monitored) can improve insulin sensitivity, ovulatory function, and androgen markers.
• Omega-3 Fatty Acids — Omega-3 supplementation in PCOS has demonstrated reductions in triglycerides, fasting insulin, free testosterone, and LH:FSH ratio in randomised trials, alongside improvement in menstrual regularity.
• N-Acetylcysteine (NAC) — NAC has insulin-sensitising properties through antioxidant mechanisms. Clinical trials demonstrate improvements in insulin resistance markers and ovulation rates in PCOS comparable to metformin in some studies.
• Magnesium — Insulin resistance in PCOS is associated with magnesium deficiency. Supplementation may improve insulin sensitivity and reduce metabolic complications.

Relevant Vaccinations

Individuals living with PCOS (polycystic ovary syndrome) may benefit from the following vaccinations. Please discuss your vaccination status with your GP or practice nurse, as eligibility and funding through the New Zealand National Immunisation Schedule may apply.

• Influenza (annual) — Women with PCOS have increased cardiovascular metabolic risk. Annual influenza vaccination reduces cardiovascular event risk associated with acute infection.
• HPV (if age-eligible) — HPV vaccination is recommended for women within the eligible age range as part of comprehensive preventive health care.
• COVID-19 — Metabolic risk factors in PCOS are associated with worse COVID-19 outcomes. Maintaining vaccination is recommended.

Dietary Guidance

Evidence-based dietary modifications play a meaningful role in the management of PCOS (polycystic ovary syndrome). The following foods are generally recommended as part of a balanced, condition-appropriate diet. A referral to a registered dietitian may be beneficial for personalised nutritional planning.

• Low glycaemic index dietary pattern — A low-GI diet reduces postprandial insulin surges central to PCOS management, with evidence supporting improvements in menstrual regularity, androgen levels, and metabolic markers.
• Inositol-rich foods (legumes, citrus, wholegrains) — Natural dietary sources of myo-inositol that support insulin signalling, particularly relevant given the inositol phosphoglycan signalling defect in PCOS.
• Mediterranean anti-inflammatory pattern — Chronic low-grade inflammation is a feature of PCOS. The Mediterranean diet has demonstrated improvements in PCOS hormonal and metabolic markers in clinical studies.
• Spearmint tea (2 cups daily) — Two cups of spearmint tea daily have demonstrated reductions in free and total testosterone and improvements in hirsutism scores in randomised trials via anti-androgenic mechanisms. An accessible dietary adjunct.
• High-fibre foods (vegetables, legumes, psyllium) — Fibre reduces postprandial glycaemia and improves gut microbiome diversity, both relevant to PCOS insulin resistance and weight management.
• Limit: refined carbohydrates, sugar-sweetened beverages, saturated fat — These pro-inflammatory, high-glycaemic foods exacerbate insulin resistance, hyperandrogenaemia, and metabolic dysfunction in PCOS.

Related Conditions & Medications

Related medications: Metformin. Related conditions: Type 2 Diabetes, Anxiety.