Oct 09, 2026

Which PCOS Supplements Have Evidence? A Graded Table

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Of every supplement sold for polycystic ovary syndrome, inositol has the most evidence: 26 randomised trials in 1,691 women, in which it made regular cycles 1.79 times as likely as placebo and matched metformin; even so, the review behind the 2023 international guideline called that evidence limited and inconclusive.^{1, 2, 3} Vitamin D has 20 trials with higher ovulation and pregnancy rates but low quality; omega-3 and chromium move insulin and lipid measures; berberine lowers testosterone, raised ovulation and clinical pregnancy rates as an add-on to fertility medicines in ten trials, and is never taken in pregnancy; N-acetylcysteine raised pregnancy rates in eight trials; spearmint has one 30-day trial; shatavari one 12-week trial in which follicle count fell and the womb lining thickened.^{4, 7, 8, 9, 11, 13, 14} PCOS itself is a GP diagnosis; the NHS now calls it polyendocrine metabolic ovarian syndrome (PMOS), previously PCOS.¹⁶

Which PCOS supplements have evidence?

Grades follow trial count, size and quality, and whether the outcome was one a woman can feel or a blood marker.

Supplement	Trials	What changed, and at what dose	Grade
Inositol	26 RCTs, 1,691 women; 30 trials in the guideline review	Regular cycles RR 1.79 vs placebo; non-inferior to metformin with fewer stomach effects; testosterone, glucose and insulin lower; 4 g myo-inositol a day^{1, 2}	Moderate
Vitamin D	20 RCTs, 1,961 women	Ovulation RR 1.42, pregnancy RR 1.44, androgens lower; trial quality limited; doses varied widely⁴	Low to moderate
Omega-3	21 clinical studies reviewed; 79-trial network meta-analysis	Insulin resistance and triglycerides lower over about 12 weeks; no cycle or pregnancy outcome^{5, 6}	Low
Berberine	12 RCTs; 10 RCTs of 713 women alongside fertility medicines	Total testosterone and LH:FSH lower vs placebo; no solid evidence on live birth; as an add-on to fertility medicines, ovulation RR 1.41 and clinical pregnancy RR 1.96^{7, 8}	Low; not in pregnancy
Chromium	6 RCTs, 351 women; 10 RCTs, 683 women	Insulin resistance lower in both; the 2018 pooling found testosterone rose, the 2025 pooling found ovulation rose at 200 µg^{9, 10}	Low, conflicting
N-acetylcysteine (NAC)	8 RCTs, 910 women; 18 studies, 2,185 women	Ovulation and pregnancy more likely than placebo, less likely than metformin; total testosterone lower^{11, 12}	Low
Spearmint tea	1 RCT, 42 women, 30 days	Free and total testosterone fell at two cups a day; women reported less hair; the measured hair score did not change¹³	Very low
Shatavari	1 RCT, 70 women, 12 weeks	Primary ovarian and endometrial outcomes: ovarian volume unchanged, follicle count fell, endometrial thickness rose; stress score fell¹⁴	Very low
Zinc, magnesium, CoQ10, agnus castus, maca	Small single trials or none	Marker outcomes only, or no PCOS trial	Ungraded

Nothing on the table has high-quality evidence; the guideline graded every supplement outcome low to moderate at best.^{2, 3} And the outcomes that matter most, a predictable cycle and a pregnancy, belong to inositol, vitamin D, NAC and, as an add-on, berberine; the rest moved blood markers. How inositol works and what UK sachets contain: what is inositol.

Which is better for PCOS, berberine or inositol?

The numbers side by side. Inositol: 26 trials, regular cycles 1.79 times as likely as placebo, a guideline listing and a clean safety record.^{1, 3} Berberine: 12 trials with lower testosterone and better insulin measures, and "no solid evidence" on live birth; as an add-on to fertility medicines in ten trials of 713 women, ovulation 1.41 times and clinical pregnancy 1.96 times as likely as the medicines alone; contraindicated in pregnancy and breastfeeding.^{7, 8} A network meta-analysis of 22 trials found the myo- plus D-chiro-inositol combination better than metformin alone for menstrual recovery, with wide intervals.¹⁵ What berberine does, and who must avoid it: what is berberine and what does it do.

What vitamin am I lacking if I have PCOS?

Possibly none; a blood test, not a guess, settles it. Low vitamin D is common across the UK in winter, which is why the NHS advises everyone to consider 10 µg a day from October to March; the PCOS trials recruited women with low levels and used larger, supervised doses.^{4, 18} Women on metformin for years can run short of vitamin B12, which the NHS lists among its effects; ask for a B12 check.¹⁷ Heavy or irregular bleeding can lower iron. No trial has tested whether correcting chromium, zinc or magnesium changes PCOS outcomes; the chromium trials used 200 µg as a supplement, not to correct a deficiency.¹⁰

Can I reduce my PCOS fast?

No, and be wary of anything that promises to. PCOS is diagnosed by a GP, usually on two of three features: irregular or absent ovulation, signs or blood tests of excess androgen, and polycystic ovaries on a scan, once thyroid and other causes are excluded.³ The guideline puts lifestyle change at the centre, with medicines chosen for the problem at hand: the combined pill for cycles and skin, metformin for insulin resistance, and letrozole or clomifene when ovulation is the goal, each prescribed and monitored.^{3, 16} What the weight-loss injections do, and how to eat on them, is on food for PCOS.

What is shatavari, and who should not take it?

Shatavari is the root of Asparagus racemosus, used in Ayurvedic tradition as a women's tonic. Its only randomised trial in PCOS, published in 2026, gave 35 women a standardised root extract and 35 a placebo for 12 weeks. The primary outcomes were ovarian and endometrial measures: ovarian volume did not differ, follicle count fell and endometrial thickness rose (p = 0.028); perceived stress fell; hormones, BMI and blood tests did not change; mild or moderate side effects were reported by 11.4% on shatavari and 8.5% on placebo.¹⁴ That one trial is the whole PCOS record. Who should not take it: anyone pregnant, anyone breastfeeding unless a doctor agrees, anyone with an oestrogen-sensitive condition such as fibrocystic breast disease, and under-18s.

What do UK inositol sachets contain?

The table is about ingredients, not products; any sachet is read by its label. A UK PCOS sachet typically combines myo-inositol, sometimes with a smaller amount of D-chiro-inositol, with minerals and vitamins such as magnesium, zinc, chromium, vitamin D3 and vitamin B12, and sometimes a herb such as shatavari; the inositol trials used 4 g of myo-inositol a day, so compare the label figure with that; chromium contributes to normal macronutrient metabolism and to the maintenance of normal blood glucose levels, zinc contributes to normal fertility and reproduction, and magnesium contributes to the reduction of tiredness and fatigue.¹ Such sachets are generally not for under-18s or during pregnancy, are used in breastfeeding only under medical supervision, are not suitable for anyone with an oestrogen-related condition where they contain shatavari, and anyone on medication, including antidiabetic medicines, asks a GP first, because inositol and chromium both lower glucose.¹⁰

What about pregnancy and trying to conceive?

Tell your GP or fertility clinic about every supplement. Berberine is never taken in pregnancy or while breastfeeding; shatavari is not for pregnancy; chromium and inositol need a word with the diabetes team if you are on antidiabetic medicines.^{7, 10} Inositol's pregnancy evidence is the uncertain live-birth signal above.^{2, 3} Vitamin D at the NHS 10 µg is standard pregnancy advice anyway.¹⁸

The Wellgard women's health guide begins with what causes BV and why it comes back.

Frequently asked questions

What are the top 5 supplements for PCOS?

By trial evidence: inositol, vitamin D, N-acetylcysteine, omega-3 and chromium, in that order, with the grades above attached.^{1, 4, 6, 10, 11} "Top" means most studied, not proven.

What is the best supplement for PCOS balance?

"Hormone balance" is not an outcome any trial measured. The measured changes are a more regular cycle (inositol), lower testosterone (inositol, berberine, NAC, spearmint) and lower insulin resistance (inositol, omega-3, chromium).^{1, 6, 7, 12, 13}

Is shatavari safe to take daily?

In the one 12-week trial, daily use produced mild or moderate effects in 11.4% of women against 8.5% on placebo, with nothing serious.¹⁴ Nothing longer has been studied, and the pregnancy and oestrogen-condition exclusions apply every day it is taken.

Who should not take shatavari?

Anyone pregnant, anyone breastfeeding unless a doctor agrees, anyone with an oestrogen-sensitive condition, and under-18s; the evidence is one trial with no safety data beyond 12 weeks.¹⁴

What does shatavari do to the female body?

In the trial it lowered a stress score and follicle count and thickened the womb lining slightly, without changing hormones, weight or ovarian size.¹⁴ No trial has measured libido or fertility outcomes.

Sources

Greff D, et al. Inositol is an effective and safe treatment in polycystic ovary syndrome: systematic review and meta-analysis. Reproductive Biology and Endocrinology, 2023. PubMed 36703143.
Fitz V, et al. Inositol for polycystic ovary syndrome: systematic review and meta-analysis for the 2023 international guideline. Journal of Clinical Endocrinology and Metabolism, 2024. PubMed 38163998.
Teede HJ, et al. Recommendations from the 2023 international evidence-based PCOS guideline. Human Reproduction, 2023. PubMed 37580037.
Yang M, et al. Vitamin D supplementation on ovulation and pregnancy in polycystic ovary syndrome: systematic review and meta-analysis. Frontiers in Endocrinology, 2023. PubMed 37593349.
Melo V, et al. Omega-3 supplementation in the treatment of polycystic ovary syndrome: a review of clinical trials and cohort. Endocrine Regulations, 2022. PubMed 35180821.
Zhao G, et al. Nutritional supplements in polycystic ovary syndrome: systematic review and network meta-analysis. Reproductive Biology and Endocrinology, 2025. PubMed 40611279.
Xie L, et al. Berberine on reproduction and metabolism in women with polycystic ovary syndrome: systematic review and meta-analysis. Evidence-Based Complementary and Alternative Medicine, 2019. PubMed 31915452.
Ha S, et al. Berberine as adjuvant therapy for reduced fertility in women with polycystic ovary syndrome: a meta-analysis. Explore, 2024. PubMed 39236662.
Tang XL, et al. Chromium supplementation in women with polycystic ovary syndrome: systematic review and meta-analysis. Journal of Obstetrics and Gynaecology Research, 2018. PubMed 28929602.
Hamsho M, et al. Therapeutic effects of chromium supplementation on women with polycystic ovarian syndrome: a systematic review and meta-analysis. Endocrinología, Diabetes y Nutrición, 2025. PubMed 41067797.
Thakker D, et al. N-acetylcysteine for polycystic ovary syndrome: systematic review and meta-analysis. Obstetrics and Gynecology International, 2015. PubMed 25653680.
Shahveghar Asl Z, et al. N-acetylcysteine on ovulation and sex hormones in women with polycystic ovary syndrome: systematic review and meta-analysis. British Journal of Nutrition, 2023. PubMed 36597797.
Grant P. Spearmint herbal tea has significant anti-androgen effects in polycystic ovarian syndrome. Phytotherapy Research, 2010. PubMed 19585478.
Mhatre Y, et al. Efficacy and safety of shatavari root extract in women with polycystic ovarian syndrome: a randomised placebo-controlled trial. Frontiers in Endocrinology, 2026. PubMed 41816216.
Zhao H, et al. Comparative efficacy of metformin, thiazolidinediones, inositol and berberine in women with PCOS: a network meta-analysis. Reproductive Health, 2021. PubMed 34407851.
NHS. Polyendocrine metabolic ovarian syndrome (PMOS). nhs.uk/conditions/polyendocrine-metabolic-ovarian-syndrome-pmos.
NHS. Side effects of metformin. nhs.uk/medicines/metformin/side-effects-of-metformin.
NHS. Vitamin D. nhs.uk/conditions/vitamins-and-minerals/vitamin-d.

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