Evidence-graded guideLast updated November 1, 2026

Best Supplements and Herbs for Women: 9 Ranked by What the Trials Found

The best supplements for women, by weight of human evidence, are iron (if your ferritin is low, which is true for about one in three menstruating women), folate (if you could become pregnant) and vitamin D (if you are deficient), followed by omega-3, magnesium, collagen peptides and the herb vitex for PMS. That list is deliberately unglamorous. The products that dominate the 'women's wellness' market right now, beef organ capsules and hormone-balancing blends, have essentially no trials behind them, while the boring nutrients above have Cochrane reviews. Collagen is the exception among the trendy options: it has a dozen small RCTs for skin hydration and elasticity that mostly point the same way.

This page is for adult women from their twenties to their fifties who want to know what has actually been tested, at what dose, and whether it applies to them. Needs change across the lifespan: iron and folate dominate the reproductive years, calcium, vitamin D and creatine matter more after 45, and we cover perimenopause and menopause in their own guides. See a doctor rather than a supplement shelf if you have heavy periods, fatigue with hair loss or breathlessness, missed periods, pelvic pain, or mood changes that interfere with daily life; the first three are classic signs of iron deficiency or thyroid disease, both of which need a blood test rather than guesswork.

One rule runs through this page: where the evidence is really about correcting a deficiency, we say so. Iron, vitamin D, folate and magnesium transform how a deficient woman feels and do nothing measurable for a replete one.

Quick answer

  • Iron — corrects the low ferritin behind fatigue in a third of menstruating women; Cochrane found it reduced anaemia by 65% and improved exercise performance
  • Folate — 400 mcg/day before conception cuts neural tube defects by about 70%; every woman who could become pregnant should take it
  • Vitamin D — corrects deficiency, supports bone and immune function; no benefit from megadoses in replete women
  • Omega-3 — 1–2 g/day EPA+DHA eases period pain and is needed in pregnancy for fetal brain development
  • Magnesium — 250–360 mg/day reduced PMS mood symptoms and menstrual migraine in small RCTs
  • Collagen peptides — 2.5–10 g/day improved skin hydration and elasticity in a review of 11 RCTs; the best-evidenced beauty supplement

The 9 best herbs and supplements for women's health

Ranked by the strength of human evidence. Strong = multiple trials or a meta-analysis. Moderate = a few small trials. Preliminary = early or animal data.

  1. Iron

    Strong evidence

    Iron deficiency is the most common nutrient deficiency in women worldwide; around 30% of menstruating women have low ferritin and 10% are anaemic. A 2016 Cochrane review of 67 trials in menstruating women found daily iron cut the risk of anaemia by 65%, raised haemoglobin by 5 g/L, and improved exercise performance and fatigue scores. Fatigue improves even in non-anaemic women with ferritin under 50 mcg/L: an 80 mg/day trial in 198 such women found a 48% drop in fatigue versus 29% on placebo at 12 weeks. The catch is that iron does nothing, and causes harm, in women who are not low, so test first.

    Key evidence
    2016 Cochrane review of 67 RCTs in menstruating women (Low)
    Studied dose
    40–80 mg elemental iron every other day (bisglycinate or ferrous sulfate) with vitamin C, for 3 months, then recheck ferritin
    Best for
    Women with heavy periods, fatigue, hair shedding, restless legs or a ferritin under 30 mcg/L
    Cautions
    Never supplement without a ferritin test: iron overload harms the liver and heart, and haemochromatosis affects 1 in 200 people of northern European descent. Constipation and nausea are common; alternate-day dosing halves them and absorbs better. Separate from levothyroxine, tetracyclines, quinolones and calcium by 2–4 hours.
    Full Iron profile

  2. Folate (folic acid or methylfolate)

    Strong evidenceVitamin B9

    A 2015 Cochrane review of 5 trials in 7,391 women found periconceptional folic acid cut neural tube defects by 69%. Because the neural tube closes by day 28, before most women know they are pregnant, every health agency recommends 400 mcg/day for all women who could conceive, and 4–5 mg/day for those with a previous affected pregnancy or on anti-epileptic drugs. Outside pregnancy, folate deficiency is uncommon in countries that fortify flour, but the MTHFR variant carried by about 10% of people reduces conversion of folic acid, which is why methylfolate is a reasonable alternative.

    Key evidence
    2015 Cochrane review of 5 RCTs, 7,391 women (De-Regil)
    Studied dose
    400 mcg/day folic acid or L-methylfolate from at least 1 month before conception through 12 weeks of pregnancy; 600 mcg/day during pregnancy
    Best for
    Every woman who could become pregnant, planned or not
    Cautions
    High-dose folic acid can mask the anaemia of B12 deficiency while nerve damage continues; take B12 alongside if you are vegan or over 50. Interacts with methotrexate and some anti-epileptics (dose adjustment needed, not avoidance). Doses above 1 mg/day need a medical reason.
    Full Folate (folic acid or methylfolate) profile

  3. Vitamin D

    Strong evidenceCholecalciferol (D3)

    Around 40% of US women are vitamin D deficient, and deficiency is linked to low mood, bone loss, muscle weakness and poor pregnancy outcomes. Supplementation corrects the deficiency reliably and reduces falls and fracture risk in deficient older adults, but the large VITAL trial (25,871 adults, 2,000 IU/day for 5 years) found no reduction in cancer, cardiovascular disease or fractures in a mostly replete population. In pregnancy, a 2019 Cochrane review found vitamin D probably reduces pre-eclampsia, gestational diabetes and low birth weight. The conclusion is consistent: take it if you are low, not as insurance.

    Key evidence
    VITAL trial (Manson, 2019) and the 2022 VITAL fracture analysis (LeBoff)
    Studied dose
    1,000–2,000 IU (25–50 mcg) vitamin D3 daily with a meal; 4,000 IU/day if 25(OH)D is under 30 nmol/L, rechecked at 3 months
    Best for
    Women who work indoors, cover their skin, have darker skin, are pregnant or breastfeeding, or are over 50
    Cautions
    Doses above 4,000 IU/day long term can raise blood calcium, particularly with calcium supplements or thiazide diuretics. Check levels if you have sarcoidosis, kidney stones or hyperparathyroidism. No meaningful drug interactions at ordinary doses.
    Full Vitamin D profile

  4. Omega-3 (EPA/DHA)

    Strong evidence

    Omega-3 has three distinct uses for women. For period pain, a 2020 meta-analysis of 8 RCTs found fish oil reduced pain scores and ibuprofen use, with a Danish trial of 42 teenagers finding pain scores fell by a third on 2 g/day. In pregnancy, DHA is required for fetal brain and eye development, and a 2018 Cochrane review of 70 trials found omega-3 cut preterm birth before 34 weeks by 42%. For heart health the benefit is dose-dependent and clearest for triglycerides. Mood trials are mixed, with EPA-rich formulas performing better than DHA-rich ones as an add-on in depression.

    Key evidence
    2018 Cochrane review of omega-3 in pregnancy, 70 RCTs (Middleton)
    Studied dose
    1–2 g/day EPA+DHA for period pain; at least 200–300 mg/day DHA in pregnancy and breastfeeding; 2–4 g/day for high triglycerides under medical supervision
    Best for
    Women with painful periods, women who are pregnant or planning to be, and anyone eating oily fish less than twice a week
    Cautions
    Above 3 g/day, omega-3 increases bleeding time; discuss with your doctor if you take anticoagulants or have heavy periods, and stop a week before surgery. Choose a brand with third-party testing for mercury and oxidation. Fishy burps are reduced by taking it frozen or with a meal.
    Full Omega-3 (EPA/DHA) profile

  5. Magnesium

    Moderate evidence

    Magnesium has small but repeatable trials for several women's complaints. A 2010 RCT in 150 women found 250 mg/day of magnesium plus 40 mg B6 reduced PMS scores more than either alone over 2 cycles, and an earlier 2-cycle trial found 360 mg/day improved premenstrual mood. For menstrual migraine, 360 mg/day across the luteal phase reduced headache days in a placebo-controlled trial. A 2017 meta-analysis of 34 RCTs found about 2 mmHg lower blood pressure, and small trials show better sleep in older adults who are low. Roughly half of women eat less than the 310–320 mg/day recommended.

    Key evidence
    2010 RCT of magnesium plus vitamin B6 for PMS (Fathizadeh), 150 women
    Studied dose
    250–360 mg elemental magnesium/day as glycinate or citrate, taken in the evening; start 2 weeks before a period for PMS or menstrual migraine
    Best for
    PMS mood symptoms, menstrual migraine, period cramps, poor sleep and muscle tension
    Cautions
    Loose stools are the main side effect; glycinate is the gentlest form. Separate from tetracycline and quinolone antibiotics and from bisphosphonates by 2–4 hours. Avoid supplementing in kidney disease without medical advice.
    Full Magnesium profile

  6. Collagen peptides

    Moderate evidence

    A 2019 systematic review of 11 RCTs (805 participants) found oral collagen hydrolysate at 2.5–10 g/day for 8–24 weeks improved skin elasticity, hydration and dermal collagen density, with no adverse events. The best single trial, 69 women aged 35–55 taking 2.5 g or 5 g/day for 8 weeks, found skin elasticity improved 7% versus placebo, more in women over 50. A 2021 meta-analysis of 19 trials confirmed the hydration and elasticity effect. Evidence for hair and nails is weaker (one open-label nail study), and the joint-pain data, while positive in athletes, uses 10 g/day. It is the one beauty supplement that has earned its place; the effect is modest and reverses when you stop.

    Key evidence
    2019 systematic review of 11 RCTs (Choi) and the 2014 Proksch RCT in 69 women
    Studied dose
    2.5–10 g/day of hydrolysed collagen peptides (bovine or marine), daily for at least 8–12 weeks
    Best for
    Women over 35 noticing skin dryness and loss of elasticity; also joint discomfort from exercise at 10 g/day
    Cautions
    Very safe. Marine collagen is unsuitable with fish allergy. Most trials were funded by manufacturers of specific peptide blends (Verisol, Peptan), so results may not transfer to every product. Collagen is not a complete protein and should not replace dietary protein.
    Full Collagen peptides profile

  7. Vitex (chasteberry)

    Moderate evidenceVitex agnus-castus

    Vitex is the best-tested herb for PMS. A 2017 systematic review and meta-analysis of 17 RCTs found it superior to placebo in 13 of 14 placebo-controlled trials, and a German trial of 170 women found 20 mg/day of a standardised extract halved overall PMS scores over 3 cycles, with 52% responding versus 24% on placebo. Smaller trials found it comparable to 20 mg fluoxetine for physical symptoms and helpful for cyclical breast pain. It acts on dopamine receptors in the pituitary and lowers prolactin slightly, which is why it also has preliminary evidence for luteal phase defects.

    Key evidence
    2017 systematic review and meta-analysis of 17 RCTs (Verkaik)
    Studied dose
    20–40 mg/day of a dried fruit extract (Ze 440 or BNO 1095), taken each morning for at least 3 cycles
    Best for
    PMS with irritability, mood swings, breast tenderness and bloating; cyclical breast pain
    Cautions
    Avoid with hormonal contraception, IVF drugs, hormone replacement and dopamine-affecting drugs (antipsychotics, Parkinson's medication). Not for pregnancy or breastfeeding. Can cause headache, nausea and acne in the first weeks.
    Full Vitex (chasteberry) profile

  8. Creatine monohydrate

    Moderate evidence

    Women store 70–80% less creatine than men and eat less of it, which may be why they respond well. A 2021 review in Nutrients summarised trials showing 3–5 g/day improves strength and lean mass gains from resistance training in women of all ages, with a 12-month trial in 47 postmenopausal women finding creatine plus training preserved hip bone density better than training alone. Small trials also report benefits for mood and cognition in women, especially during sleep deprivation and in the low-oestrogen luteal phase. Despite the stereotype, creatine does not cause bulky muscle or significant water retention in women at 3–5 g/day.

    Key evidence
    2021 lifespan review of creatine in women's health (Smith-Ryan) and 2015 postmenopausal bone RCT (Chilibeck)
    Studied dose
    3–5 g/day creatine monohydrate, every day, no loading phase needed
    Best for
    Women who lift or do any resistance training, and women over 45 trying to preserve muscle and bone
    Cautions
    Mild water retention (0.5–1 kg) in the first weeks in some women. Check with a doctor first if you have kidney disease. Avoid creatine blends with added stimulants or 'fat burners'.
    Full Creatine monohydrate profile

  9. Lactobacillus probiotics (vaginal and urinary health)

    Moderate evidence

    The vaginal microbiome is normally dominated by lactobacilli, and their loss underlies bacterial vaginosis and recurrent thrush. A 2014 review of 7 RCTs found oral or vaginal Lactobacillus (especially L. rhamnosus GR-1 and L. reuteri RC-14) reduced bacterial vaginosis recurrence when used alongside antibiotics, and a 2013 Cochrane review found probiotics with antibiotics raised short-term clearance rates. For recurrent UTIs, a 2012 RCT in 252 postmenopausal women found L. rhamnosus GR-1 plus L. reuteri RC-14 was slightly less effective than daily trimethoprim but caused no antibiotic resistance. Strain matters; general 'women's probiotic' blends without these strains have not been tested.

    Key evidence
    2014 systematic review of 7 RCTs for bacterial vaginosis recurrence (Homayouni)
    Studied dose
    At least 1 billion CFU/day each of L. rhamnosus GR-1 and L. reuteri RC-14 (or L. crispatus CTV-05 vaginally), for 2–6 months
    Best for
    Women with recurrent bacterial vaginosis, thrush after antibiotics, or recurrent UTIs
    Cautions
    Avoid in severe immunosuppression or with a central venous line, where rare bloodstream infections have been reported. Probiotics are an adjunct to, not a replacement for, antibiotics in confirmed infection. Bloating in the first week is common.
    Full Lactobacillus probiotics (vaginal and urinary health) profile

How to choose

  • Get ferritin, 25(OH)D and a full blood count before buying anything: these three tests decide whether iron and vitamin D will change your life or do nothing.
  • If you could become pregnant, folate is non-negotiable; add 200–300 mg/day DHA and check iron once you are pregnant.
  • If PMS is the main complaint, start with vitex 20 mg each morning for 3 cycles and magnesium 250–360 mg in the luteal phase; if symptoms are severe enough to disrupt work or relationships, ask about PMDD, which responds to SSRIs.
  • If painful periods dominate, omega-3 at 1–2 g/day for 2–3 cycles plus magnesium is the evidence-based combination; heavy or worsening period pain needs a scan to rule out endometriosis and fibroids.
  • If skin and hair are the goal, collagen peptides at 2.5–10 g/day for 12 weeks are the only beauty supplement with consistent trials; check ferritin and thyroid before blaming hair loss on a vitamin gap.
  • If you are over 45, shift the emphasis to creatine with resistance training, vitamin D, dietary calcium and protein; see the perimenopause guide for hot flashes and sleep.

What to skip

Beef organ supplements (desiccated liver, 'ancestral' blends)

There is not a single randomised trial of beef organ capsules for energy, hormones, fertility or anything else in women. Liver is a concentrated food, so the capsules do supply vitamin A, B12, copper and some iron, but typical doses (3 g/day) deliver only 1–2 mg iron, and the preformed vitamin A can exceed 3,000 mcg/day with the larger serving sizes, which is the ceiling in pregnancy. If you want what liver offers, eat 100 g of liver once a week; if you want iron, take iron.

Hair, skin and nails gummies with biotin

Biotin corrects hair loss only in the rare people who are deficient, and the 5,000–10,000 mcg in gummies interferes with thyroid, troponin and hormone blood tests, causing false results that the FDA has warned about. Collagen has the trials; biotin has the marketing.

Hormone-balancing blends (DIM, maca, 'cycle support' powders)

DIM has preliminary data for oestrogen metabolite ratios, not for symptoms; maca has two small libido trials and no hormone effect; the blends combine ten ingredients at a fraction of any studied dose. 'Balance' is not a measurable endpoint. Pick a symptom and treat that.

Calcium supplements by default

Most women can reach 1,000–1,200 mg/day from food, and supplemental calcium (not dietary) was linked to a 20–30% higher heart-attack risk in several meta-analyses and raises kidney stone risk. Supplement only the gap between your diet and 1,200 mg, and only if a diet check shows one.

Safety and when to see a clinician

  • See a clinician first if you have heavy periods (soaking a pad hourly, clots larger than a coin), fatigue with breathlessness or hair loss, missed periods, pelvic pain, unexplained weight change, or mood changes that interfere with daily life. These point to iron deficiency, thyroid disease, PCOS, endometriosis or depression, all of which need a diagnosis.
  • Iron is the one supplement here that is dangerous when you do not need it. Never take it without a ferritin test, and keep it away from children, for whom a bottle of adult iron tablets can be fatal.
  • Vitex interacts with hormonal contraception, HRT, fertility drugs and dopamine-acting medications. Stop it as soon as you find out you are pregnant.
  • Thyroid medication: iron, calcium and magnesium all block levothyroxine absorption. Take levothyroxine alone on waking and the minerals at least 4 hours later.
  • Pregnancy: folate, iron (if low), vitamin D and DHA are the evidence-based set. Vitex, high-dose vitamin A (including desiccated liver), and most herbal blends have no pregnancy safety data and should be stopped.
  • Blood thinners: omega-3 above 3 g/day and high-dose vitamin E affect bleeding. Tell your prescriber, and stop supplements a week before surgery.

What matters as much as any herb

  • Two or three resistance-training sessions a week are the single best intervention for bone, muscle, mood and insulin sensitivity across a woman's life, and they are what makes creatine and protein worth taking.
  • Eat 1.2–1.6 g of protein per kg of body weight daily, spread across meals: most women eat far less, and it does more for skin, hair, muscle and satiety than any supplement above.
  • Sleep 7 to 9 hours. Short sleep raises cortisol and appetite, worsens PMS and lowers pain thresholds, and the magnesium and collagen trials were not run on exhausted participants.
  • Keep alcohol under 7 drinks a week: it raises breast cancer risk by about 7–10% per daily drink, worsens hot flashes and sleep, and depletes folate and magnesium.
  • Iron-rich eating is cheaper than capsules: red meat or lentils with a vitamin C source, cast-iron cooking, and not drinking tea or coffee with meals can double absorption.

Frequently asked questions

What are the best vitamins for women to take daily?

For most women under 50, the evidence supports folate (400 mcg) if you could become pregnant, vitamin D3 (1,000–2,000 IU) if you get little sun, and iron only if a ferritin test shows you are low. A general multivitamin is reasonable insurance with a poor diet but has not reduced heart disease or cancer in large trials. Over 50, add vitamin B12 and consider creatine and dietary calcium.

What is the best collagen supplement for women?

The trials used hydrolysed collagen peptides (not gelatin or bone broth) at 2.5–10 g/day, mostly the Verisol bovine peptides at 2.5 g or Peptan at 5–10 g, for 8–12 weeks. Marine and bovine collagen performed similarly. Look for 'hydrolysed collagen peptides', a dose of at least 2.5 g, and third-party testing; ignore added biotin, which adds nothing but interferes with blood tests.

Are beef organ supplements good for women?

No trial has tested them, so nobody knows. They are a concentrated food that supplies vitamin A, B12 and copper, and small amounts of iron, which could help if your diet lacks those. The risk is vitamin A: liver capsules at the larger serving sizes can exceed the pregnancy ceiling of 3,000 mcg/day. If the goal is iron or energy, a ferritin test and a targeted iron supplement are more effective and far cheaper.

Which herbs are good for women's hormones?

Vitex has the best trials for PMS and cyclical breast pain, and black cohosh for menopausal hot flashes (see our menopause guide). Ashwagandha has one perimenopause RCT. Red raspberry leaf, dong quai and maca are popular but have little or no controlled evidence for hormone symptoms. 'Balancing hormones' is not something a trial can measure; pick a symptom and treat that.

Should women take iron every day?

Only if a blood test shows low ferritin or anaemia. If it does, alternate-day dosing (40–80 mg elemental iron every other day) absorbs better and causes less nausea and constipation than daily dosing, according to Swiss trials published since 2017. Recheck ferritin after 3 months and stop when it is above 50 mcg/L, since excess iron is harmful.

Is creatine good for women or will it make me bulky?

Creatine at 3–5 g/day improves strength, lean mass and possibly mood and bone density in women, and the 'bulky' fear is unfounded: women gain about 0.5–1 kg of water in the first weeks and then build muscle only in proportion to their training. It is one of the safest and best-studied supplements for women of any age.

Can I take these supplements with the contraceptive pill?

Iron, folate, vitamin D, omega-3, magnesium, collagen, creatine and probiotics are all compatible with hormonal contraception. Vitex is the exception: it acts on the pituitary and should not be combined with the pill, hormonal IUDs, HRT or fertility treatment. St John's wort, not listed here, makes the pill fail and must be avoided.

References

  1. Low MS, Speedy J, Styles CE, et al.. Daily iron supplementation for improving anaemia, iron status and health in menstruating women. Cochrane Database of Systematic Reviews (2016)View source
  2. De-Regil LM, Peña-Rosas JP, Fernández-Gaxiola AC, Rayco-Solon P. Effects and safety of periconceptional oral folate supplementation for preventing birth defects. Cochrane Database of Systematic Reviews (2015)View source
  3. Manson JE, Cook NR, Lee IM, et al.. Vitamin D supplements and prevention of cancer and cardiovascular disease (VITAL). New England Journal of Medicine (2019)View source
  4. LeBoff MS, Chou SH, Ratliff KA, et al.. Supplemental vitamin D and incident fractures in midlife and older adults. New England Journal of Medicine (2022)View source
  5. Choi FD, Sung CT, Juhasz ML, Mesinkovsk NA. Oral collagen supplementation: a systematic review of dermatological applications. Journal of Drugs in Dermatology (2019)View source
  6. Proksch E, Segger D, Degwert J, et al.. Oral supplementation of specific collagen peptides has beneficial effects on human skin physiology: a double-blind, placebo-controlled study. Skin Pharmacology and Physiology (2014)View source
  7. Verkaik S, Kamperman AM, van Westrhenen R, Schulte PFJ. The treatment of premenstrual syndrome with preparations of Vitex agnus castus: a systematic review and meta-analysis. American Journal of Obstetrics and Gynecology (2017)View source
  8. Fathizadeh N, Ebrahimi E, Valiani M, et al.. Evaluating the effect of magnesium and magnesium plus vitamin B6 supplement on the severity of premenstrual syndrome. Iranian Journal of Nursing and Midwifery Research (2010)View source
  9. Smith-Ryan AE, Cabre HE, Eckerson JM, Candow DG. Creatine supplementation in women's health: a lifespan perspective. Nutrients (2021)View source
  10. Homayouni A, Bastani P, Ziyadi S, et al.. Effects of probiotics on the recurrence of bacterial vaginosis: a review. Journal of Lower Genital Tract Disease (2014)View source
  11. Middleton P, Gomersall JC, Gould JF, et al.. Omega-3 fatty acid addition during pregnancy. Cochrane Database of Systematic Reviews (2018)View source
  12. Iron: fact sheet for health professionals. NIH Office of Dietary Supplements (2024)View source

Related conditions

More guides

Not sure which one fits you?

Ask AskMN. It knows these studies, checks interactions with the medications you tell it about, and it is free and unlimited, no account needed.

Ask about women's health

This guide is educational and is not medical advice. Herbs and supplements can interact with prescription medicines and are not regulated like drugs. Talk with a clinician or pharmacist before starting anything new, especially if you are pregnant, breastfeeding, have a chronic condition, or take medication.