Women's health supplements are an industry of promises and a desert of evidence. This guide covers the few things with genuine clinical support — and is upfront about where the science thins out. Written with the women who actually walk into our three stores in mind.

Who this is for

If you have heavy or irregular cycles; if PMS has become more than a mild week; if you're in your forties and noticing the patterns shifting; if you're peri- or post-menopausal; if PCOS is on your record — this is the starting place. It is not a substitute for a gynaecologist for diagnosis.

Cycle support (reproductive years)

Magnesium

Magnesium glycinate at 300–400 mg has more clinical evidence for PMS than almost anything else on the supplement shelf. It eases cramps, irritability, breast tenderness, and headaches. Take it daily through the cycle, not just during the premenstrual window — the effect compounds over months.

Vitamin B6 (P5P form)

50–100 mg daily of the P5P (pyridoxal-5-phosphate) form helps PMS-related mood, particularly when combined with magnesium. Don't exceed 100 mg long-term — high-dose B6 can cause peripheral neuropathy.

Vitex (chasteberry)

Vitex agnus-castus is one of the few herbs with consistent clinical trial data for PMS. 200–400 mg standardised extract, taken in the morning, daily for at least 3 months before judging. Particularly useful for cycle irregularity and PMS-D (PMS with low mood).

Evening primrose oil

Mixed evidence — works for some women (particularly breast pain), does nothing for others. 1000–2000 mg daily for 3 months is the standard trial.

PCOS — what actually helps

PCOS (polycystic ovary syndrome) is metabolic, not just reproductive. Insulin resistance is the underlying engine for most cases. The supplements that genuinely help:

• Inositol (myo + d-chiro 40:1 ratio) — 2 g twice daily of myo-inositol with 50 mg d-chiro-inositol. Strong clinical evidence for improving insulin sensitivity, regularising cycles, and supporting fertility. Give it 3 months.
• N-acetyl cysteine (NAC) — 600 mg twice daily. Improves insulin sensitivity and ovulatory function. Often used alongside inositol.
• Vitamin D3 — almost universally low in PCOS. 4000 IU daily.
• Berberine — works on insulin pathways similarly to metformin. 500 mg three times daily before meals. Don't combine with metformin without medical guidance.

PCOS deserves a gynaecologist's involvement. Supplements complement, not replace, that conversation.

Perimenopause (typically late 30s to early 50s)

Perimenopause is the years before periods stop, when hormones swing wildly. Symptoms: hot flushes, sleep disturbance, anxiety, brain fog, weight redistribution, joint aches, lower libido. The body is recalibrating — and it can take 5–10 years. Supplements help; HRT helps more for those who choose it. Don't dismiss HRT because of outdated 1990s fears — the modern evidence supports it for most women.

Magnesium glycinate

The same workhorse from the cycle section. 300–400 mg evening. Helps sleep, mood, joint aches, headaches.

Black cohosh (Cimicifuga racemosa)

The most studied herb for hot flushes. 40 mg standardised extract daily. Give it 8 weeks. Works for roughly half of women who try it. Don't use if you have a history of liver disease.

Sage

Salvia officinalis at 280 mg standardised extract daily — clinical trials show reduction in hot flushes and night sweats. Often paired with black cohosh.

Adaptogens

Ashwagandha for the anxious-and-not-sleeping profile; rhodiola for the foggy-and-flat profile. See the stress & mood guide.

Phytoestrogens (red clover, soy isoflavones)

Mixed evidence — work for some, do nothing for others. Worth a 3-month trial. Avoid if you have a history of oestrogen-sensitive cancer without oncology input.

Post-menopause: the long game

After periods stop for 12 months, the focus shifts to long-term health: bone density, cardiovascular, cognitive. The non-negotiables:

• Vitamin D3 + K2 — bone and cardiovascular protection.
• Calcium only if dietary intake is genuinely low — supplemental calcium without K2 has cardiovascular question marks. Get it from food first.
• Omega-3 1–2 g EPA+DHA — cognitive and cardiovascular.
• Collagen peptides 10–15 g daily — joint, skin, possibly bone. Modest but real evidence.
• Magnesium for sleep, blood pressure, and mood.

What's overhyped

• 'Hormone-balancing' blends that don't list mechanism — usually a sprinkle of everything.
• Maca for libido — fine, weak evidence.
• DIM and I3C for oestrogen — interesting research, often pushed at higher doses than studied.
• Wild yam cream — body doesn't convert it to progesterone, despite the marketing.

Red flags

Heavy bleeding (soaking through a pad/tampon every hour); bleeding between periods if you're peri/post-menopausal; sudden severe pelvic pain; breast lumps; nipple discharge; family history of ovarian/breast cancer plus new symptoms — these are gynae-now, not pharmacy-shelf.

Your Onelife shortcut

Educational only. Not medical advice. Hormonal symptoms deserve a gynaecologist's input. Supplements can interact with hormonal contraceptives, fertility treatments, and HRT. Always disclose what you're taking.