Women's health supplements: what the evidence says

Almost everything people cite for strontium comes from strontium ranelate — a prescription drug that reduced fractures but was restricted across Europe for heart attack risk and is no longer marketed.

A synthetic isoflavone derivative for osteoporosis whose largest and best-designed trial was flatly negative — no bone density benefit, no fracture benefit — and which caused lymphocytopenia in a meaningful fraction of women taking it.

Evening primrose oil is one of the best-studied supplements that mostly does not work.

Fennel has repeatedly reduced menstrual pain in small randomized trials — meta-analyses find it beats placebo and performs roughly like mefenamic acid — but almost every study is small, short and single-region, so certainty stays low.

Despite decades of use for hot flushes, the pooled randomized evidence does not show black cohosh beats placebo.

Red clover isoflavones produce at best a small reduction in hot flushes — around one to two flushes per day more than placebo in pooled trials — which reviewers have questioned as falling short of clinical meaningfulness.

Shatavari (Asparagus racemosus) is a staple Ayurvedic women's tonic with a very thin modern trial record — a couple of small randomized studies in muscle strength and lactation, and essentially nothing rigorous for menopause or fertility.

Wild yam is sold as a "natural progesterone" alternative, and that premise is simply wrong: the human body cannot convert its diosgenin into progesterone or DHEA.

D-mannose looked promising in small open-label studies, but the largest and best-designed trial — nearly 600 women in primary care — found no benefit over placebo for preventing recurrent UTIs.

Uva ursi (bearberry) has been tested head-to-head as an antibiotic-sparing treatment for uncomplicated UTI and lost — worse symptom resolution and more cases of pyelonephritis in the herbal arm.

DIM reliably shifts estrogen metabolite ratios in the lab, but the largest clinical trial — 551 women with abnormal cervical cytology — found no effect on any real outcome.

Dong quai (Angelica sinensis) is marketed as a "female ginseng" for hot flashes and menstrual complaints, but the one well-designed placebo-controlled trial of dong quai alone found it no better than placebo.

A Mexican shrub sold for female libido on the strength of tradition alone — no controlled trial has ever tested damiana for sexual function.

D-chiro-inositol is the less-studied inositol isomer, and the enthusiasm rests largely on one small 1999 trial that later work failed to reproduce.

Fertility blends bundle antioxidants, vitamins and herbs into an expensive monthly subscription.

A traditional "partus preparator" tea taken in late pregnancy, but the only decent randomised trial found no shortening of labour's first stage and only a ~10-minute effect on the second.

A bitter herb sold mainly as a breastfeeding "galactagogue," almost always blended with fenugreek — and it has never been tested alone in a controlled human trial.

Multi-herb blends for hot flushes typically combine black cohosh, red clover, soy isoflavones, dong quai and wild yam — but the best evidence puts the phytoestrogen effect at only about one fewer hot flush per day, and Cochrane found black cohosh no better than placebo.

PMS blends usually stack chasteberry, calcium, vitamin B6, magnesium and evening primrose oil — of which calcium has the strongest single-ingredient trial support and evening primrose the weakest.

A traditional bleeding herb with two small Iranian randomized trials behind it.

A traditional antispasmodic bark with real smooth-muscle activity in the laboratory but essentially no controlled human data for menstrual cramps.

A uterine antispasmodic whose entire human record consists of 19th-century clinical reports.

A tannin-rich herb long used for heavy periods, but its only human studies are topical ones for mouth ulcers and wounds.

A classical Ayurvedic uterine tonic with centuries of use and almost no controlled human data.

An Ayurvedic bark used for menstrual complaints and PCOS.

A punicic-acid-rich oil marketed for menopausal symptoms.

Concentrated secoisolariciresinol diglucoside from flaxseed, sold for hormone balance.

A compound from cruciferous vegetables that measurably shifts estrogen metabolite ratios.

A Malaysian women's tonic with a handful of small trials, none of which establishes benefit for menopausal symptoms.

Fenugreek-based blends sold to increase milk supply.

Postnatal blends have not been tested as products.

An over-the-counter transdermal cream whose absorption is erratic and whose clinical record is one small trial from 1999.

A culinary herb tested once, as a tea, in women with PCOS.

A Thai root with unusually potent phytoestrogens.

A traditional galactagogue with no trial of its own.

A North American root used traditionally to induce labour and ease menstrual cramps.

A slow-growing, now-threatened American woodland root used in Western herbal medicine for irregular cycles and fertility.

Anti-inflammatory and antioxidant blends marketed for endometriosis-related pelvic pain.

DIM, indole-3-carbinol and calcium D-glucarate blends sold to help the body clear excess oestrogen.

Gelatin made by boiling donkey hide, used in Chinese medicine as a blood tonic for anaemia and skin.

A classic eight-herb Chinese formula combining the qi tonic Si Jun Zi Tang with the blood tonic Si Wu Tang, used for fatigue and post-partum or post-illness depletion.

The four-herb blood tonic that underlies most Chinese gynaecological formulas, used for irregular or painful periods.