Home Ingredients Rhapontic Rhubarb (Rheum rhaponticum root extract)
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Rhapontic Rhubarb (Rheum rhaponticum root extract)

Rheum rhaponticum L.
Evidence Level
Limited
2 Clinical Trials
4 Documented Benefits
2/5 Evidence Score

Rhapontic rhubarb is the root of Rheum rhaponticum, a non-laxative species of rhubarb used as a source of hydroxystilbene glycosides such as rhaponticin and desoxyrhaponticin and their aglycones rhapontigenin and desoxyrhapontigenin. The strongest clinical evidence for this botanical comes from the standardized ERr 731 branded extract, which has been studied in placebo-controlled trials of perimenopausal women and shown to reduce Menopause Rating Scale scores, hot flushes, and night sweats through selective estrogen receptor beta activation. Generic rhapontic rhubarb extracts on the supplement market typically lack the same level of analytical standardization and controlled trial evidence, so this entry frames generic rhubarb root as a category whose most rigorous human data are tied to the ERr 731 form rather than to unstandardized commodity extracts. All three studies cited here tested ERr 731, and all three share a co-author who directs the German company that makes it, so this is one body of work on one preparation rather than independent evidence for rhubarb root in general. That extract has been registered in Germany as a medicine, Phytoestrol N, since 1993, while in the United States the same material is sold as a dietary supplement.

Studied Dose ERr 731 standardized extract: 4 mg per enteric-coated tablet once daily.
Active Compound Hydroxystilbene glycosides rhaponticin and desoxyrhaponticin, plus aglycones rhapontigenin and desoxyrhapontigenin; act preferentially at estrogen receptor beta.

Benefits

Helps reduce menopausal hot flashes (standardized form)

Standardized rhapontic rhubarb root extract has been shown in placebo-controlled trials of perimenopausal women to reduce the frequency and severity of hot flashes and night sweats over 12 weeks; most rigorous data are tied to the standardized ERr 731 form rather than generic rhubarb extracts.

Supported by Trial 2, Trial 1

Supports overall menopausal symptom relief

Daily use of standardized rhapontic rhubarb extract is associated with improvements in composite menopausal symptom scores covering vasomotor, psychological, and somatic complaints, supporting comfort during the perimenopausal transition without reliance on hormone therapy.

Supported by Trial 1, Trial 2

Helps maintain mood and emotional balance

Clinical trial data with standardized rhapontic rhubarb showed a significant improvement versus placebo in every individual Menopause Rating Scale item, including depressed mood, irritability and anxiety, in perimenopausal women. These are single self-rated questions inside a menopause questionnaire rather than a study of mood problems in their own right, so read this as emotional symptoms of the menopausal transition easing, not as treatment for anxiety or depression.

Supported by Trial 1, Trial 2

Acts selectively on estrogen receptor beta

Rhapontic rhubarb hydroxystilbenes activate estrogen receptor beta while showing no measurable activation of estrogen receptor alpha in laboratory cell assays. That is selective estrogen receptor activity, not an absence of estrogen activity, so the hormone-related cautions on this page still apply to women with hormone-sensitive conditions.

Supported by Trial 1, Trial 2

Mechanism of action

1

Selective estrogen receptor beta activation

The aglycones rhapontigenin and desoxyrhapontigenin preferentially bind and transactivate estrogen receptor beta in cellular reporter assays while showing essentially no transactivation of estrogen receptor alpha. That work tested the standardized ERr 731 extract and its aglycones in yeast and human cell lines rather than in women, and the authors propose this receptor profile as the reason the extract eases climacteric complaints.

2

Modulation of hypothalamic thermoregulation

Estrogen receptor beta activation in hypothalamic neurons is implicated in stabilizing the thermoregulatory set point, providing a hypothesized mechanism by which rhapontic rhubarb hydroxystilbenes reduce hot flash frequency and night sweats in perimenopause.

3

Lack of uterotrophic estrogen receptor alpha signaling

Because rhapontic rhubarb hydroxystilbenes do not transactivate estrogen receptor alpha, no uterine stimulation is expected. In the 12-week trial there was no difference from placebo in gynecological findings including endometrial biopsies, and 90 days of dosing in ovariectomized rats produced no uterine growth and no shift in proliferation marker genes. That is reassuring for the standardized extract, though the controlled human data run only to 12 weeks.

Clinical trials

1
12-week perimenopausal RCT (standardized form)

Multicenter, randomized, double-blind, placebo-controlled trial of one enteric-coated standardized rhapontic rhubarb tablet (ERr 731) daily for 12 weeks (Heger et al., Menopause).

109 perimenopausal women with climacteric complaints.

Standardized rhapontic rhubarb extract produced significantly greater reductions in Menopause Rating Scale II total score and in every individual symptom on that scale, including the psychological items, versus placebo. Was rated effective and well tolerated, with no estrogenic endometrial effects observed.

2
Confirmatory 12-week perimenopausal RCT

Multicenter, randomized, double-blind, placebo-controlled confirmatory trial of standardized rhapontic rhubarb root extract (ERr 731) for 12 weeks (Kaszkin-Bettag et al., Alternative Therapies in Health and Medicine).

112 perimenopausal women with menopausal symptoms.

Confirmatory trial replicated significant reductions in Menopause Rating Scale total score and in hot flash frequency and severity versus placebo over 12 weeks, with good tolerability. It shares four authors with the first trial, including one affiliated with the German manufacturer of the extract, and it tested the same branded material, so it is a replication by the same research group rather than independent confirmation.

Side effects and drug interactions

Common Potential side effects

Mild gastrointestinal complaints such as stomach discomfort or nausea have been reported.
Occasional headache or dizziness may occur.
Allergic-type skin reactions are uncommon but possible in sensitive individuals.
Breast tenderness has been reported infrequently in menopausal women.
Unstandardized rhubarb root extracts can vary in stilbene content and effect. For the standardized extract, placebo-controlled safety data run only to 12 weeks; the longer record comes from uncontrolled follow-up and from post-marketing reports in Germany, where it has been sold since 1993 and hypersensitivity and stomach complaints were the commonest reports.

Important Drug interactions

May theoretically interact with hormone replacement therapy or oral contraceptives via estrogen receptor signaling.
Caution with tamoxifen or aromatase inhibitors due to estrogen receptor activity.
Concurrent use with other phytoestrogen supplements may compound estrogenic-type activity.
Theoretical interaction with anticoagulants such as warfarin warrants medical supervision.

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Frequently asked questions about Rhapontic Rhubarb (Rheum rhaponticum root extract)

What is rhapontic rhubarb used for?

Rhapontic rhubarb (Rheum rhaponticum) is used mainly for menopausal symptoms. A specific standardized extract (ERr 731) is studied for easing hot flashes and other menopausal complaints, acting selectively on estrogen-beta receptors.

Does rhapontic rhubarb help with menopause?

The standardized rhapontic rhubarb extract has notable research for reducing hot flashes and other menopausal symptoms, with a good safety record in the studies so far. It acts on one estrogen receptor subtype rather than as a general estrogen. That evidence is for the one standardized extract, not for rhubarb root supplements in general.

How much rhapontic rhubarb should I take?

The studied standardized extract is taken once daily at the labeled dose; follow product labeling. This is the medicinal rhubarb root, different from culinary rhubarb.

Is rhapontic rhubarb safe?

The standardized menopausal extract has a good safety record in studies and acts selectively on estrogen-beta receptors. As with any hormone-related supplement, women with hormone-sensitive conditions should check with a doctor first.

What is Rhapontic Rhubarb?

Rhapontic rhubarb is the root of Rheum rhaponticum, a non-laxative species of rhubarb used as a source of hydroxystilbene glycosides such as rhaponticin and desoxyrhaponticin and their aglycones rhapontigenin and desoxyrhapontigenin.

What is the recommended dosage of Rhapontic Rhubarb?

The clinically studied dose is ERr 731 standardized extract: 4 mg per enteric-coated tablet once daily. Always follow the product label and check with a healthcare provider for personal advice.

Is Rhapontic Rhubarb safe, and does it have side effects?

For most healthy adults, Rhapontic Rhubarb is well tolerated at studied doses. Reported effects can include: Mild gastrointestinal complaints such as stomach discomfort or nausea have been reported. Occasional headache or dizziness may occur. It may also interact with some medications. Rhapontic Rhubarb is not right for everyone, so check with a healthcare provider first if you are pregnant or breastfeeding, have a medical condition, or take prescription medication.

Does Rhapontic Rhubarb interact with any medications?

Possible interactions include: May theoretically interact with hormone replacement therapy or oral contraceptives via estrogen receptor signaling. Caution with tamoxifen or aromatase inhibitors due to estrogen receptor activity. If you take prescription medication, check with a pharmacist or doctor before using it.

How strong is the scientific evidence for Rhapontic Rhubarb?

NutraSmarts rates the evidence for Rhapontic Rhubarb as Limited (2 out of 5). It is backed by 2 clinical trials and 8 cited references summarized on this page. A higher rating reflects more, larger, and better-designed human studies.

References(8 citations)

Evidence ratings on NutraSmarts are based on the totality of human clinical research, with emphasis on randomized controlled trials, meta-analyses, and systematic reviews. The references below directly support claims made throughout this page.

  1. Heger M, Ventskovskiy BM, Borzenko I, Kneis KC, Rettenberger R, Kaszkin-Bettag M, Heger PW. 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;Menopause. 2006 Sep-Oct;13(5):744-59..PubMedUsed to support: Foundational 12-week RCT of standardized rhapontic rhubarb (ERr 731) showing significant reductions in Menopause Rating Scale II score and hot flashes versus placebo.
  2. Kaszkin-Bettag M, Ventskovskiy BM, Solskyy S, Beck S, Hasper I, Kravchenko A, Rettenberger R, Richardson A, Heger PW. Confirmation of the efficacy of ERr 731 in perimenopausal women with menopausal symptoms. Alternative Therapies in Health and Medicine. 2009;Altern Ther Health Med. 2009 Jan-Feb;15(1):24-34..PubMedUsed to support: Confirmatory 12-week RCT of standardized rhapontic rhubarb extract in 112 perimenopausal women, supporting efficacy on Menopause Rating Scale and hot flashes versus placebo.
  3. Wober J, Möller F, Richter T, Unger C, Weigt C, Jandausch A, Zierau O, Rettenberger R, Kaszkin-Bettag M, Vollmer G. Activation of estrogen receptor-beta by a special extract of Rheum rhaponticum (ERr 731), its aglycones and structurally related compounds. Journal of Steroid Biochemistry and Molecular Biology. 2007;J Steroid Biochem Mol Biol. 2007;107(3-5):191-201..PubMedUsed to support: Mechanistic study showing standardized rhapontic rhubarb extract and its aglycones selectively activate estrogen receptor beta but not estrogen receptor alpha in cellular reporter assays.
  4. Hasper I, Ventskovskiy BM, Rettenberger R, et al. Long-term efficacy and safety of the special extract ERr 731 of Rheum rhaponticum in perimenopausal women with menopausal symptoms. Menopause. 2009;16(1):117-31..PubMedUsed to support: Two consecutive 48-week open observational follow-ups (96 weeks total) of the ERr 731 randomized trial cohort, reporting sustained MRS II improvement and no clinically relevant change in safety parameters. This is the page's only long-term efficacy and safety evidence and it is uncontrolled, which is exactly why it should be visible on the page.
  5. Chang JL, Montalto MB, Heger PW, et al. Rheum rhaponticum Extract (ERr 731): Postmarketing Data on Safety Surveillance and Consumer Complaints. Integr Med (Encinitas). 2016;15(3):34-9..PubMedUsed to support: German surveillance from 1993 to June 2014: about 140 million daily doses placed on the market and 124 adverse event reports, commonest hypersensitivity (74) and gastrointestinal (47). Supports the long-term safety wording, and records that the extract was registered in Germany as Phytoestrol N in July 1993 and later marketed as femi-loges, while it is sold in the United States as the dietary supplement Estrovera. The paper applies marketing authorization holder language explicitly to femi-loges and calls Phytoestrol N commercially registered, and the disclosure paragraph of this same paper is also the source confirming that co-author Rettenberger directs the manufacturer.
  6. Keiler AM, Papke A, Kretzschmar G, et al. Long-term effects of the rhapontic rhubarb extract ERr 731® on estrogen-regulated targets in the uterus and on the bone in ovariectomized rats. J Steroid Biochem Mol Biol. 2012;128(1-2):62-8..PubMedUsed to support: Ninety days of dietary ERr 731 produced neither a uterotrophic response nor modulation of uterine proliferation marker genes, and it did not affect estrogen-deprivation bone loss. Supplies the animal locator the page previously asserted without a citation.
  7. Dubey VP, Sureja VP, Kheni DB Efficacy evaluation of standardized Rheum rhaponticum root extract (ERr 731 (®)) on symptoms of menopause: A systematic review and meta-analysis study. J Biomed Res. 2024;38(3):278-286..PubMedUsed to support: Systematic review and meta-analysis of four ERr 731 studies (390 participants) finding a significant reduction in Menopause Rating Scale score versus control, while noting potential bias and high heterogeneity. Establishes the size and the limits of the whole ERr 731 evidence base in one citation.
  8. Heger PW, Hotz D, Kalder M, et al. Association between Extract Rheum rhaponticum 731 (ERr 731) prescription and subsequent breast cancer. Breast Cancer Res Treat. 2025;212(1):139-148..PubMedUsed to support: Retrospective German records cohort, 5,686 ERr 731 users versus 17,058 non-users and 2,616 versus 7,848 HRT users, finding no increased breast cancer diagnosis risk (OR 1.01 and 0.96). Relevant to the estrogen-related cautions the page raises, though two authors are employed by Health Research Services GmbH.