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PCOS/PMOS affects about 1 in 8 women of reproductive age, yet many go years without a diagnosis. It affects hormones, metabolism, weight, skin, mood and fertility, so it is much more than an ovarian condition. This guide follows the 2023 international evidence-based PCOS guideline.
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In the pharmacy
Spot it
Think of PCOS/PMOS when a woman asks about, or buys products for:
- irregular or missed periods
- persistent acne, excess facial or body hair, or thinning scalp hair
- difficulty getting pregnant, or repeated ovulation or pregnancy tests
- weight gain around the waist, or difficulty losing weight
- dark, velvety skin at the neck or armpits, a sign of insulin resistance
A few questions help: How often do your periods come? How long have you been trying to conceive? Has anyone ever checked your hormones or blood sugar?
Counsel and support
- Lifestyle first. Healthy eating and regular activity improve insulin resistance, cycles and wellbeing. Even a 5% weight loss in women with excess weight can help. Focus on health, not only the scale.
- Inositol. A well-tolerated option, with far fewer stomach side effects than metformin, and a good choice for women who cannot tolerate metformin or prefer a supplement. Recommend a product with myo-inositol and D-chiro-inositol in the 40:1 ratio found in blood plasma, which in a comparison of seven ratios was the most effective at restoring ovulation. Advise daily use and a review of cycles after about three months.
- Vitamin D. Low levels are common in women with PCOS/PMOS and worth correcting.
- Trying to conceive. Folic acid 400 mcg daily from at least one month before trying (5 mg on prescription if her BMI is 30 or more, or other risk factors apply).
- Medicine checks. If she takes metformin, advise taking it with food and building up the dose slowly to limit stomach upset.
Refer to a prescriber
- Suspected PCOS/PMOS that has never been assessed.
- No period for 3 months or more, or very heavy or unpredictable bleeding.
- Rapidly worsening hair growth, a deepening voice or other signs of virilisation (refer urgently).
- Trying to conceive for 12 months, or 6 months if she is 35 or over, or sooner if periods are very irregular.
- Low mood, anxiety or signs of an eating difficulty.
In the clinic
Confirm the diagnosis
In adults, PCOS/PMOS is diagnosed when two of these three are present and other causes are excluded:
- Irregular cycles or no ovulation: from 3 years after the first period, cycles shorter than 21 or longer than 35 days, or fewer than 8 a year. Between 1 and 3 years after the first period, cycles shorter than 21 or longer than 45 days. From 1 year after the first period, any cycle longer than 90 days. No period by age 15, or more than 3 years after breast development began.
- High androgens: clinical (hirsutism, acne, scalp hair loss) or biochemical (raised total or free testosterone, for example calculated free testosterone or free androgen index; androstenedione and DHEAS can be checked if testosterone is not raised).
- Polycystic ovaries on ultrasound, or a raised AMH blood test.
If both irregular cycles and high androgens are present, an ultrasound or AMH test is not needed. Within 8 years of the first period, both irregular cycles and high androgens are needed, and ultrasound and AMH are not used. Exclude thyroid disease (TSH), high prolactin and non-classic congenital adrenal hyperplasia (17-OH progesterone).
Use our calculators: PCOS/PMOS diagnosis checker, free androgen index, hirsutism score, HOMA-IR and TyG index.
Screen for the health risks
| Check | How often |
|---|---|
| Weight, waist size and blood pressure | Weight and waist at each visit; blood pressure at least once a year |
| Blood sugar: oral glucose tolerance test (preferred), or fasting glucose or HbA1c | At diagnosis, then every 1 to 3 years depending on risk |
| Lipids | At diagnosis, then as risk factors suggest |
| Low mood, anxiety, eating difficulties and body image | At diagnosis and when concerns arise |
Treat
- Irregular cycles, hirsutism and acne in women not trying to conceive: the combined oral contraceptive pill is first line.
- Metabolic features: metformin, particularly with a BMI of 25 or more. Start low and build up.
- Inositol: can be considered through shared decision-making, as above. The 2023 guideline notes the evidence is not yet strong enough to recommend one particular type, dose or ratio.
- Trying to conceive: letrozole is the first-line medicine to induce ovulation. Start folic acid beforehand, at a higher dose if her BMI is over 30.
- Endometrial protection: with infrequent periods, arrange regular withdrawal bleeds or a progestogen, and investigate unusual bleeding.
Refer to a specialist
- Signs of virilisation or a very high testosterone level: exclude an androgen-secreting tumour.
- Not ovulating, or trying for 12 months (6 months if 35 or over, as the American Society for Reproductive Medicine advises).
- Abnormal endometrial thickness or bleeding.
Key references
- Teede HJ, et al. Recommendations from the 2023 international evidence-based guideline for the assessment and management of polycystic ovary syndrome. Fertil Steril 2023;120(4):767-793.
- Teede H, et al. Polyendocrine metabolic ovarian syndrome, the new name for polycystic ovary syndrome. The Lancet, May 2026.
- Nordio M, et al. The 40:1 myo-inositol/D-chiro-inositol plasma ratio is able to restore ovulation in PCOS patients. Eur Rev Med Pharmacol Sci 2019;23(12):5512-5521.
Prepared by the Draxer Clinical Advisory Department for health professionals. It supports, and does not replace, clinical judgement and national guidelines.