Last checked September 2026 against 23 sources · Editorial policy
Supplements for hot flashes
The supplements with the best evidence for hot flashes are soy isoflavones, which cut hot flash frequency by 20.6% in one meta-analysis, and black cohosh, rated moderate-certainty in a 2026 International Menopause Society review but not better than placebo in a Cochrane review. Vitamin E showed a small effect, about one fewer hot flash a day. Omega-3, magnesium, flaxseed, dong quai and red clover didn't beat placebo. None matches HRT or prescription non-hormonal medicines.
Soy isoflavones cut hot flashes by 20.6% in a meta-analysis; black cohosh and vitamin E help a little. Omega-3, magnesium, flaxseed and dong quai didn't beat placebo.
Supplements for hot flashes: expectation vs reality
What people often expect
“The best supplement for hot flashes will work as well as HRT”
What the evidence shows
In the MsFLASH trials, low-dose estradiol cut hot flashes by 2.4 a day more than placebo; omega-3 supplements had no effect at all. Placebo itself reduces hot flashes, which is why so many supplements look good in uncontrolled studies and then fail in controlled trials, as happened with pollen extract when controlled studies were pooled.
Supplements for hot flashes and night sweats, rated by evidence
Soy isoflavones for hot flashes
In a meta-analysis of 17 trials, soy isoflavone supplements with a median 54 mg a day reduced hot flash frequency by 20.6% and severity by 26.2% compared with placebo, over 6 weeks to 12 months. Products with more than 18.8 mg of genistein were more than twice as effective. Concentrated extracts have been used safely for up to 6 months.
Learn more →Black cohosh for hot flashes
A 2012 Cochrane review of sixteen trials found no significant difference from placebo in hot flash frequency, and HRT worked better than black cohosh. More recent reviews are more positive: the 2026 IMS review rated the evidence for hot flashes as moderate certainty. Rare but serious liver damage has been reported with black cohosh products.
Learn more →Vitamins for hot flashes
Vitamin E has the most research among vitamins, and the effect is small: in one study, women taking vitamin E averaged one fewer hot flash a day. High-dose vitamin E may raise bleeding risk and interacts with blood thinners. Vitamin D has high-certainty evidence for safety and moderate evidence for fracture risk, but not for hot flashes.
Learn more →Omega-3 and magnesium didn't work
In the MsFLASH trials, 1.8 g a day of omega-3 fatty acids had no effect on hot flash frequency or bother. In a placebo-controlled trial of more than two hundred women, magnesium oxide didn't reduce hot flash scores and caused more diarrhea. Both have other uses, but not for hot flashes.
Learn more →Evening primrose oil and night sweats
In a 2024 meta-analysis, evening primrose oil lowered hot flash severity vs placebo in studies shorter than 6 months, but not frequency or duration, and the authors called the evidence insufficient. One trial found fewer and milder night sweats but no change in hot flashes. Mild nausea and headache were reported.
Learn more →Branded hot flash supplements
Estroven Complete's rhapontic rhubarb extract reduced the number and severity of hot flashes from week 4 in a 12-week trial of 109 women. Amberen improved 16 of 21 symptoms vs placebo in pooled trials. Relizen's pollen extract looked effective in uncontrolled studies, but the benefit disappeared when controlled studies were pooled.
Learn more →Herbs that didn't beat placebo
Dong quai didn't relieve hot flashes more than placebo in a 24-week trial, and didn't act like estrogen on the uterus or vagina. Red clover's Promensil extract didn't beat placebo in pooled trials. St John's wort with vitex wasn't better than placebo in late perimenopause. Flaxseed bars didn't reduce hot flashes in 188 women.
Learn more →Supplements vs proven hot flash treatments
The North American Menopause Society doesn't recommend supplements or herbal remedies for hot flashes. It recommends hormone therapy as the most effective option, and without hormones, CBT, hypnosis, SSRIs or SNRIs, gabapentin, fezolinetant and oxybutynin. In MsFLASH, escitalopram and venlafaxine cut hot flashes by 1.4 and 1.8 a day more than placebo.
Learn more →Hot flash supplements by the numbers
From the studies on this page
fewer hot flashes with soy isoflavone supplements vs placebo
20.6%
1
2.4
1.8 g
Most supplement trials are small and short, and a strong placebo effect makes uncontrolled studies look better than they are.
Hot flash supplements compared
Soy isoflavones
Learn more →Good for
The best-supported supplement: about 20.6% fewer hot flashes.Watch
Modest effect; not recommended by NAMS; may not suit women who shouldn't take estrogen.Black cohosh
Learn more →Good for
Moderate-certainty evidence in a 2026 review.Watch
Cochrane found no benefit; rare liver damage.Rhapontic rhubarb extract (Estroven Complete)
Learn more →Good for
Fewer and milder hot flashes from week 4 in a placebo-controlled trial.Watch
Evidence rests on a few trials of one extract.Vitamin E
Good for
About one fewer hot flash a day in a study.Watch
Small effect; high doses raise bleeding risk.Omega-3, magnesium, flaxseed
Good for
Other health uses.Watch
No effect on hot flashes in placebo-controlled trials.
How to choose a supplement for hot flashes
- Choose products that state the dose of the active ingredient, such as mg of isoflavones or genistein.
- Check with your doctor if you take blood thinners, antidepressants or tamoxifen.
- Stop black cohosh if you notice dark urine, yellow skin or belly pain.
- Remember supplements aren't FDA-approved before sale; quality and content can vary.
When to see a doctor instead of relying on hot flash supplements
Hot flashes or night sweats disrupting sleep or work
Ask about HRT or proven non-hormonal medicines.
More →Night sweats with weight loss or fever
See a doctor; night sweats can have other causes.
More →Liver symptoms on a supplement
Stop it and see a doctor if you get dark urine, jaundice or belly pain.
History of breast cancer
Talk to your oncology team before taking phytoestrogens or herbs.
Supplements for hot flashes: questions women ask
What supplements help hot flashes?
Soy isoflavones have the most consistent evidence, with about a fifth fewer hot flashes. Black cohosh and rhapontic rhubarb extract show some benefit in trials. Omega-3, magnesium, flaxseed and dong quai didn't beat placebo.
What vitamins help with hot flashes?
Only vitamin E has shown an effect, and it's small: about one fewer hot flash a day. Vitamin D and calcium matter for bones, not hot flashes. High-dose vitamin E may raise bleeding risk.
Does vitamin D help hot flashes?
There's no good evidence it does. The 2026 IMS review found high-certainty evidence that vitamin D is safe and moderate evidence that it lowers fracture risk, but not that it reduces hot flashes.
What is the best herb for hot flashes?
Black cohosh, though evidence is mixed: a 2026 review rated it moderate certainty, while a Cochrane review found no benefit over placebo. Dong quai and red clover didn't work in trials.
Related →What supplements help night sweats?
Evidence is thin. One trial found evening primrose oil reduced night sweats but not hot flashes. Soy isoflavones and black cohosh target hot flashes generally. CBT reduced night sweat frequency in the MENOS 2 trial.
Are hot flash supplements safe?
Mostly well tolerated in short trials, but they're not FDA-approved before sale, and long-term safety is unknown. Black cohosh has rare liver cases; vitamin E and dong quai can interact with blood thinners.
How long do hot flash supplements take to work?
Trials usually lasted about 12 weeks, and rhapontic rhubarb extract worked from week 4. Soy isoflavone trials ran from 6 weeks to 12 months.
What works better than supplements for hot flashes?
HRT is the most effective treatment. Without hormones, CBT, hypnosis, SSRIs or SNRIs, gabapentin and fezolinetant are recommended by The North American Menopause Society.
Related →Sources
- Taku K, Melby MK, Kronenberg F, et al. Extracted or synthesized soybean isoflavones reduce menopausal hot flash frequency and severity: systematic review and meta-analysis of randomized controlled trials. Menopause. 2012;19(7):776-90.
- Maunder A, Mardon AK, Rao V, et al. Complementary therapies for management of menopausal symptoms: a systematic review to inform the update of the International Menopause Society recommendations on women's midlife health. Climacteric. 2026;29(2):165-209.
- Leach MJ, Moore V. Black cohosh (Cimicifuga spp.) for menopausal symptoms. Cochrane Database Syst Rev. 2012;2012(9):CD007244.
- National Center for Complementary and Integrative Health. Menopausal symptoms: in depth.
- Guthrie KA, LaCroix AZ, Ensrud KE, et al. Pooled Analysis of Six Pharmacologic and Nonpharmacologic Interventions for Vasomotor Symptoms. Obstet Gynecol. 2015;126(2):413-422.
- Park H, Qin R, Smith TJ, et al. North Central Cancer Treatment Group N10C2 (Alliance): a double-blind placebo-controlled study of magnesium supplements to reduce menopausal hot flashes. Menopause. 2015;22(6):627-32.
- Pruthi S, Qin R, Terstreip SA, et al. A phase III, randomized, placebo-controlled, double-blind trial of flaxseed for the treatment of hot flashes: North Central Cancer Treatment Group N08C7. Menopause. 2012;19(1):48-53.
- Hirata JD, Swiersz LM, Zell B, et al. Does dong quai have estrogenic effects in postmenopausal women? A double-blind, placebo-controlled trial. Fertil Steril. 1997;68(6):981-6.
- Lethaby A, Marjoribanks J, Kronenberg F, et al. Phytoestrogens for menopausal vasomotor symptoms. Cochrane Database Syst Rev. 2013;2013(12):CD001395.
- Acquarulo EL, Hernandez EC, Kodzodziku F, et al. The efficacy of purified pollen extract for reducing vasomotor symptoms in women: a systematic review and meta-analysis. Menopause. 2024;31(2):154-159.
- National Center for Complementary and Integrative Health. Soy: usefulness and safety.
- National Center for Complementary and Integrative Health. Black cohosh: usefulness and safety.
- Thevi T, De S, Soe HHK. Evening Primrose Oil for Menopause Hot Flashes: Systematic Review and Meta-Analysis. J Menopausal Med. 2024;30(3):127-134.
- Kazemi F, Masoumi SZ, Shayan A, et al. The Effect of Evening Primrose Oil Capsule on Hot Flashes and Night Sweats in Postmenopausal Women: A Single-Blind Randomized Controlled Trial. J Menopausal Med. 2021;27(1):8-14.
- Heger M, Ventskovskiy BM, Borzenko I, et al. Efficacy and safety of a special extract of Rheum rhaponticum (ERr 731) in perimenopausal women with climacteric complaints: a 12-week randomized, double-blind, placebo-controlled trial. Menopause. 2006;13(5):744-59.
- Radzinsky VE, Uspenskaya Y, Shulman LP, et al. Succinate-Based Dietary Supplement for Menopausal Symptoms: A Pooled Analysis of Two Identical Randomized, Double-Blind, Placebo-Controlled Clinical Trials. Obstet Gynecol Int. 2019;2019:1572196.
- van Die MD, Burger HG, Bone KM, et al. Hypericum perforatum with Vitex agnus-castus in menopausal symptoms: a randomized, controlled trial. Menopause. 2009;16(1):156-63.
- The North American Menopause Society. The 2023 nonhormone therapy position statement of The North American Menopause Society. Menopause. 2023;30(6):573-590.
- NHS. Night sweats.
- Estroven. Estroven Complete Multi-Symptom Menopause Relief product page (checked September 2026).
- Thomson CA, Chow HHS, Wertheim BC, et al. A randomized, placebo-controlled trial of diindolylmethane for breast cancer biomarker modulation in patients taking tamoxifen. Breast Cancer Res Treat. 2017;165(1):97-107.
- US Food and Drug Administration. Dietary supplements.
- Ayers B, Smith M, Hellier J, et al. Effectiveness of group and self-help cognitive behavior therapy in reducing problematic menopausal hot flushes and night sweats (MENOS 2): a randomized controlled trial. Menopause. 2012;19(7):749-59.
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