Key Takeaways
- Equelle provides 10 mg of S-equol plus 240 mg of calcium in two daily tablets; the Kobayashi equol products we carry provide 2 mg of equol a day.
- Only some people's gut bacteria make equol from soy: roughly 20 to 30% of adults in Western study groups versus 50 to 70% in many Asian groups.
- In a 12-week trial of 160 Japanese women who did not make equol, 10 mg a day of S-equol cut hot-flash frequency 58.7% versus 34.5% with placebo.
- The evidence comes from small, short trials run mostly in Japanese women, several with industry authors, and we found no trial that tested 2 mg of equol a day for symptoms.
- Japan's Food Safety Commission set a safe upper limit of 70 to 75 mg of soy isoflavones a day, with 30 mg a day for extra intake from foods for specified health uses.
- Talk to your doctor first if you have had breast cancer, take tamoxifen, thyroid medication or iron, are pregnant or breastfeeding, or have a soy allergy.
If hot flashes or night sweats have you comparing menopause supplements, you have probably come across Equelle, the US supplement built around a soy-derived compound called S-equol. Look a little further and you will also find Japanese equol supplements, often with very different labels. Are they the same thing, and does the difference matter for you?
This guide compares Equelle and the Japanese equol supplements we carry on verified facts: how much equol each provides per day, where it comes from, what else is in the tablet, and what the clinical trials actually tested. We also explain the "equol producer" idea, Japan's safety limits for soy isoflavones, and who should talk to a doctor before trying any of them.
Featured in this article
Inochi no Haha Equol by Kobayashi Pharmaceutical: 2 mg equol, 28 mg GABA and 25 mg theanine in one daily tablet, 30-day pouch
What Is Equelle, and What Is S-Equol?
Equelle is a menopause supplement sold in the US by Bonafide Health, part of Pharmavite, which is a subsidiary of Japan's Otsuka Pharmaceutical. Each two-tablet daily serving provides 10 mg of S-equol plus 240 mg of calcium. S-equol is a compound some people's gut bacteria make from daidzein, a soy isoflavone; Equelle's comes from fermented soy germ[1][2].
Equol has an unusual history. It was first isolated from horse urine and only identified decades later in human urine, as a product of gut bacteria breaking down the isoflavones in soy. Those bacteria make just one mirror-image form of the molecule, S-equol, which binds preferentially to a type of estrogen receptor called estrogen receptor beta[3].
That is why people ask whether Equelle is estrogen. It is not a hormone. S-equol is a plant-derived compound that interacts with estrogen receptors, which is why it is studied for menopause. Equelle's label lists S-equol as the key ingredient, with fermented soy germ and dicalcium phosphate among the other ingredients, and it contains soy[1].
The same ingredient has a longer history in Japan. Otsuka sells it there under the EQUELLE name, where its standard tablets provide 10 mg of equol in four tablets and its "Petit" version provides 10 mg in two. Otsuka says it ferments soy germ with a lactic acid bacterium and, citing its own research, describes itself as the first to identify an equol-producing lactic acid bacterium suitable for use in food[4].
Are You an Equol Producer, and Does It Matter?
Only some people carry gut bacteria that turn soy daidzein into equol: roughly 20–30% of adults in Western study groups, compared with 50–70% in many Asian groups[5]. It matters because many S-equol trials enrolled only non-producers, the women whose bodies cannot make equol from the soy they eat[6][7].
Estimates vary with the population and the test. One review puts the figure at about 50% of Asians and 25% of non-Asians[8]. In a Japanese trial of women aged 40 to 59, just 34.3% were producers at the start[9], which is a useful reminder that eating soy all your life does not guarantee you make equol.
Can you become a producer? So far, apparently not on demand. A recent systematic review found 12 randomized trials (730 participants) that tried soy isoflavones, probiotics, fermented soy, seaweed or wheat bran, and none of them significantly converted non-producers into producers[10]. This is the logic behind taking equol directly: if your gut does not make it, a supplement supplies the finished compound.
Producer status is usually measured in urine after eating soy. In Japan, a Nagoya testing company has turned its urine equol test into a mail-in kit[11]. Outside Japan, ask your clinician whether testing is available to you. If you already make equol, the trials below, many of them run only in non-producers, tell you less about what an equol supplement would add.
Equelle vs Japanese Equol Supplements: What's in Each?
The biggest difference is the daily amount. Equelle provides 10 mg of S-equol a day, the amount used in most clinical trials. The Kobayashi equol products we carry provide 2 mg a day, paired with GABA, theanine or beauty-focused nutrients, while Kikkoman's tablet provides soy isoflavones rather than equol[1][8][12].
| Product | Maker | Tablets per day | Equol per day (mg) | Equol source on label | Other ingredients per day |
|---|---|---|---|---|---|
| Equelle (US) | Pharmavite (Otsuka group) | 2 | 10 (S-equol) | Fermented soy germ | Calcium 240 mg |
| EQUELLE (Japan, standard tablets) | Otsuka Pharmaceutical | 4 | 10 | Soy germ fermented with lactic acid bacteria | See maker label |
| Inochi no Haha Equol | Kobayashi Pharmaceutical | 1 | 2 | Fermented soy germ extract | Fermented soy isoflavone ingredient 25.5 mg (contains the 2 mg equol), GABA 28 mg, theanine 25 mg, enzyme-treated hesperidin 31.3 mg |
| Equol α + Beauty Support | Kobayashi Pharmaceutical | 2 | 2 | Fermented soy germ extract | Fermented soy isoflavone ingredient 25.5 mg (contains the 2 mg equol), zinc 6.0 mg, GABA-containing barley extract 31.4 mg, astaxanthin-containing algae extract 3.3 mg, bird's nest extract 1.4 mg, vitamin E 0.7 mg |
| Kikkoman Soy Isoflavone Aglycone | Kikkoman | 2 | None | Not applicable | Soy isoflavone aglycone 25 mg, grape seed proanthocyanidin 200 mg, folic acid 400 µg, vitamin D3 30 µg |
Sources for the table: the Equelle label[1], Otsuka's product page[4], the Kobayashi label[12] and the product information on our store pages. All five contain soy.
Same Raw Material, Different Dose
Equelle and the Kobayashi tablets start from the same kind of ingredient: soy germ that has been fermented so that it contains equol[1][12]. The real difference is the amount: 2 mg a day versus 10 mg. We did not find any trial that tested 2 mg a day on its own for menopausal symptoms. In a one-year Japanese study that included a 2 mg group, the significant drop in a marker of bone breakdown was reported for the 10 mg group[7]. So it is not fair to expect the Kobayashi products to reproduce the trial results described below, and you should never take more tablets than the label says in an attempt to reach 10 mg.
What the Japanese formulas offer instead is a different idea of a daily supplement: a lower equol amount combined with other ingredients. Inochi no Haha Equol adds GABA and theanine, two amino acids often chosen for relaxation (our guide to GABA in Japanese supplements explains the background). Equol α + Beauty Support adds zinc, an astaxanthin-containing algae extract and bird's nest extract. In Japan, Inochi no Haha Equol is labeled as a general dietary supplement (eiyo hojo shokuhin), not as a Food with Function Claims or FOSHU product, so it carries no government-reviewed or notified health claim[12].
Equelle's 240 mg of calcium also matters in practice. Its maker advises taking it one to two hours apart from iron supplements and four hours apart from thyroid medication, because calcium can affect their absorption[1].
Featured in this article
Equol α + Beauty Support by Kobayashi Pharmaceutical: 2 mg equol plus 6.0 mg zinc, astaxanthin-containing algae extract and bird's nest extract in 2 daily tablets
What Do Clinical Trials Show for Menopausal Symptoms?
Small trials, mostly in Japanese women, suggest that 10 mg a day of S-equol can modestly reduce hot flashes. In the largest placebo-controlled trial we found, hot-flash frequency fell 58.7% with S-equol versus 34.5% with placebo over 12 weeks. A meta-analysis found an overall benefit, although two of its five trials did not[6][13].
| Trial | Participants (n) | S-equol (mg/day) | Duration (weeks) | Main result |
|---|---|---|---|---|
| Placebo-controlled RCT[6] | 160 equol non-producing postmenopausal Japanese women (126 completed) | 10 | 12 | Hot-flash frequency −58.7% vs −34.5% with placebo; less neck and shoulder stiffness |
| Placebo-controlled RCT[9] | 134 Japanese women aged 40–59 | 10 or 30 | 12 | Mood scores improved vs placebo in the 30 mg group |
| Active-comparator RCT, no placebo[14] | 102 US postmenopausal women with 5+ hot flashes a day | 10, 20 or 40 (vs soy isoflavones) | 8 | Similar hot-flash reductions in all groups at week 8; 10 and 20 mg better for muscle and joint pain |
| Randomized, no-supplement control[15] | 57 postmenopausal Japanese women | 10 | About 12 (3 months) | 81% vs 53% of women reported improved climacteric (menopausal) symptoms (unblinded; supplement also contained lactobionic acid) |
| Placebo-controlled RCT, bone[7] | 93 non-producing postmenopausal Japanese women | 2, 6 or 10 | 52 | Bone-breakdown marker −23.94% with 10 mg vs −2.87% with placebo |
Hot Flashes: Moderate Evidence
The strongest single study enrolled 160 postmenopausal Japanese women who did not produce equol and had at least one hot flash a day. After 12 weeks on 10 mg of S-equol daily, hot flashes fell from about 2.9 to about 1.0 a day on average, a 58.7% drop, compared with 34.5% in the placebo group. Hot-flash severity and neck or shoulder stiffness also improved more than with placebo[6]. Note how large the placebo response was, about a third, which is one reason to be cautious about individual testimonials.
A systematic review and meta-analysis pooled five randomized trials with 728 women, covering both equol supplements and soy isoflavones in women who make equol. Three found a significant benefit and two did not, but the combined result showed lower hot-flash scores, and the authors rated the risk of bias as generally low[13].
Mood, Muscles and Joints: Emerging Evidence
In a 12-week Japanese trial, women taking 10 mg three times a day reported better mood and less fatigue than those on placebo[9]. In the only published US randomized trial we found, which compared S-equol with soy isoflavones rather than with placebo, 10 mg a day appeared to be as effective as isoflavones for hot-flash frequency and was better for muscle and joint pain in this pilot study[14]. Equelle's own product page cites this US trial, together with the bone and hot-flash trials above[1].
What the Research Cannot Tell You Yet
The trials are small and short, usually 8 to 12 weeks for symptoms. Most enrolled Japanese women, for whom, as one review notes, hot flashes are a relatively minor complaint, and, as of that review, the only US hot-flash trial lacked a placebo group[8]. Several studies have authors from companies behind S-equol products, including Pharmavite[14] and Otsuka[16]. Because S-equol has a half-life of 7 to 10 hours, trials often split the 10 mg into two doses a day[8]. For soy isoflavones more broadly, the US National Center for Complementary and Integrative Health says supplements may help reduce hot flashes, but the effect may be small and results have not been completely consistent[17]. For a wider look at non-hormonal options, see our evidence-based guide to menopause supplements.
Is Equol Safe? Side Effects, Isoflavone Limits and Breast Cancer
In trials lasting up to one year, no serious side effects were reported with 10 mg a day of S-equol, and hormone levels, breast imaging and uterine checks stayed normal in the studies that measured them. Long-term data are limited, so anyone with a history of breast cancer or another hormone-sensitive condition should ask their doctor first[6][7][16].
Reported Side Effects
The largest hot-flash trial reported no serious adverse effects and no changes in clinical measurements[6]. In the 12-week mood trial, one woman taking 30 mg a day developed a rash over her body[9]. A 12-week trial at 10 and 30 mg a day found no abnormal results in hormone levels, vaginal cells, uterine lining thickness or mammograms[16], and a one-year trial found no differences in sex or thyroid hormones[7]. Equelle's maker notes that supplements can cause stomach upset and suggests taking the tablets with food if that happens[1]. For soy products in general, reported side effects include bloating, constipation, diarrhea and nausea[17]. Every product in this article contains soy, so none is suitable if you have a soy allergy.
Japan's Limits on Soy Isoflavones
Japan's Food Safety Commission has published specific numbers. It set a safe upper limit for total soy isoflavone intake of 70–75 mg a day (as aglycone), partly because 150 mg a day taken for five years was linked to overgrowth of the uterine lining (endometrial hyperplasia) in an Italian study. For extra isoflavones taken on top of a normal diet in foods for specified health uses (FOSHU), it set 30 mg a day, and it advised against such extra intake for pregnant women, infants and young children[18]. Kikkoman's 25 mg of aglycone a day is below that 30 mg figure. The commission's limits are written for soy isoflavones and do not give a separate number for equol, but it did note that equol producers taking high doses continuously might face more risk than non-producers[18]. In practice, avoid stacking several soy isoflavone or equol products at once.
Breast Cancer History, Medications and Pregnancy
A review of S-equol concluded that the safety data, though limited, do not suggest cause for concern for breast or uterine tissue[8]. Memorial Sloan Kettering Cancer Center describes studies of soy in breast cancer patients as mixed, says soy supplements can affect how tamoxifen works, and advises talking with your care team if you take an aromatase inhibitor[19]. If you have had breast cancer or another hormone-sensitive condition, check with your oncologist before taking any equol or isoflavone supplement. The products here are not intended for pregnancy or breastfeeding, and if you take prescription medication, ask your doctor or pharmacist first.
Why Is Equol So Closely Tied to Japan?
Equol is closely tied to Japan because the country combines a soy-rich diet, a higher share of equol producers and the companies that brought S-equol to market. Otsuka makes the fermented soy germ ingredient behind EQUELLE, most symptom trials were run with Japanese women, and Japan even sells mail-in urine tests for equol status[4][5][11].
In Japan, producer status is part of everyday supplement marketing. A testing company and Japanese supplement listings cite the same figure, that only about one in two Japanese people make equol, and the listings use it to explain why a product offers equol directly[11][12]. On our own site, the Inochi no Haha Equol page is the one Google most often shows for searches such as "menopause supplements Japan".
The Japanese products also reflect a different style. Kobayashi's Inochi no Haha line is a women's health brand in Japan (we cover its background in our article on the Inochi no Haha brand), and its equol products combine a small amount of equol with supporting ingredients in one or two tablets. Japan's regulators, meanwhile, have published explicit isoflavone limits that are worth knowing wherever you live[18]. If you are new to buying from Japan, our guide on what to know before buying Japanese supplements covers labels and shipping questions.
Which Option Suits You?
Choose Equelle or another 10 mg S-equol product if you want the amount used in the clinical trials. A Japanese 2 mg equol formula suits women who prefer a lower-dose daily routine that pairs equol with GABA and theanine. A soy isoflavone tablet such as Kikkoman's may suit women who already make equol or simply want isoflavones.
- You want the trial dose: 10 mg of S-equol a day, the amount in Equelle in the US and in Otsuka's EQUELLE in Japan[1][4]. This is the only option on the list that matches the published symptom trials.
- You want a lower-dose Japanese routine: Inochi no Haha Equol provides 2 mg of equol with GABA, theanine and hesperidin in a single tablet. We found no symptom trial at this dose, so judge it as a gentle daily supplement rather than a copy of the trial protocol.
- You want equol plus beauty-focused nutrients: Equol α + Beauty Support adds zinc, an astaxanthin-containing algae extract and bird's nest extract to the same 2 mg of equol. Its label warns that too much zinc can interfere with copper absorption, so check any other zinc you take.
- You make equol, or you prefer isoflavones: Kikkoman's tablet provides 25 mg of soy isoflavone aglycone with grape seed proanthocyanidin, vitamin D3 and folic acid, within Japan's 30 mg extra-intake figure[18].
- Ask a doctor first: if you are pregnant or breastfeeding, have a soy allergy, have a history of breast cancer or another hormone-sensitive condition, take tamoxifen or an aromatase inhibitor, or take thyroid medication or iron[19][1].
Whatever you choose, give it time. The symptom trials ran for 8 to 12 weeks[6][14], so plan on about three months of daily use before deciding whether it helps, and keep a simple hot-flash diary so you can judge the change rather than rely on memory.
Our Recommendations
We carry Japanese equol and soy isoflavone supplements, not Equelle. The picks below are the options we selected for women who want a Japanese product, with the differences above in mind.
Inochi no Haha Equol: Equol With GABA and Theanine
Why We Selected This: From Kobayashi Pharmaceutical, the maker of the Inochi no Haha women's health line, this one-tablet formula combines 2 mg of equol from fermented soy germ with 28 mg of GABA, 25 mg of theanine and enzyme-treated hesperidin. We chose it for women who want a simple, lower-dose Japanese equol routine, and its label is clear about every active amount.
It is the page on our site that searchers most often find for "menopause supplements Japan", and it is the easiest of the three to fit into a day: one tablet, with or without food.
Equol α + Beauty Support: Equol With Zinc and Astaxanthin
Why We Selected This: Also from Kobayashi Pharmaceutical, this two-tablet formula pairs the same 2 mg of equol with 6.0 mg of zinc, an astaxanthin-containing algae extract, bird's nest extract and vitamin E, without added coloring, fragrance or preservatives. We chose it for women who want their equol supplement to cover beauty-focused nutrients too.
View Equol α + Beauty Support →
Kikkoman Soy Isoflavone Aglycone: An Isoflavone Alternative
Why We Selected This: From Kikkoman, the Japanese soy sauce maker, this tablet provides 25 mg of soy isoflavone aglycone (at least half of it genistein), 200 mg of grape seed proanthocyanidin, 30 µg of vitamin D3 and 400 µg of folic acid per two-tablet serving. We chose it for women who already make equol or who prefer a soy isoflavone supplement, and its isoflavone amount stays within Japan's 30 mg extra-intake figure[18].
View Kikkoman Soy Isoflavone Aglycone →
Product Comparison
| Product | Brand | Equol per day (mg) | Additional Ingredients | Best For |
|---|---|---|---|---|
| Inochi no Haha Equol | Kobayashi Pharmaceutical | 2 | GABA, theanine, enzyme-treated hesperidin | A simple one-tablet Japanese equol routine |
| Equol α + Beauty Support | Kobayashi Pharmaceutical | 2 | Zinc, astaxanthin-containing algae extract, bird's nest extract, GABA-containing extract, vitamin E | Equol plus beauty-focused nutrients |
| Kikkoman Soy Isoflavone Aglycone | Kikkoman | None (25 mg isoflavone aglycone) | Grape seed proanthocyanidin, vitamin D3, folic acid | Equol producers and women who prefer isoflavones |
You can browse more options in our women's health collection.
Conclusion
Equelle and the Japanese equol supplements share an ingredient, equol from fermented soy germ, but not a dose. Equelle provides the 10 mg a day used in the published trials, which suggest a modest reduction in hot flashes for women who do not make equol themselves, based on small, short studies run mostly in Japan. The Kobayashi products provide 2 mg a day alongside other ingredients, and we found no trial that tested that lower amount on its own for menopausal symptoms.
Before choosing, consider whether you might already be an equol producer, keep your total soy isoflavone intake within Japan's limits, and talk to your doctor if you have a history of breast cancer, take hormone-related or thyroid medication, or are pregnant. If a lower-dose Japanese equol routine fits what you are looking for, Inochi no Haha Equol is a good place to start.
Equelle is a trademark of its owner. Naturacare is not affiliated with Bonafide Health, Pharmavite or Otsuka Pharmaceutical and does not sell Equelle; it is named here only to compare published product facts.
This article is for informational purposes only and does not constitute medical advice. Consult a healthcare professional before starting any new health regimen, especially if you have existing health conditions or take medications. Statements about dietary supplements have not been evaluated by the FDA and are not intended to diagnose, treat, cure, or prevent any disease.
Frequently Asked Questions
- Equelle: Menopause Supplement, S-equol Multi-Symptom Relief (product page, Supplement Facts and FAQ)
- Pharmavite: Pharmavite Announces Acquisition of Bonafide Health (company press release)
- Setchell KD, Clerici C. Equol: history, chemistry, and formation. J Nutr. 2010
- Otsuka Pharmaceutical: EQUELLE (product information)
- Sekikawa A, et al. S-Equol as a Gut-Derived Phytoestrogen Targeting Estrogen Receptor β: A Narrative Review. Nutrients. 2025
- Aso T, et al. A natural S-equol supplement alleviates hot flushes and other menopausal symptoms in equol nonproducing postmenopausal Japanese women. J Womens Health. 2012
- Tousen Y, et al. Natural S-equol decreases bone resorption in postmenopausal, non-equol-producing Japanese women: a pilot randomized, placebo-controlled trial. Menopause. 2011
- Utian WH, Jones M, Setchell KD. S-equol: a potential nonhormonal agent for menopause-related symptom relief. J Womens Health. 2015
- Ishiwata N, et al. New equol supplement for relieving menopausal symptoms: randomized, placebo-controlled trial of Japanese women. Menopause. 2009
- Li J, et al. Converting Equol Nonproducers to Producers: A Systematic Review of Randomized Clinical Trials. Food Sci Nutr. 2026
- Healthcare Systems / Kyocera: urine equol measurement press release (@Press, Japanese). 2023
- Kobayashi Pharmaceutical Equol 30 tablets: label information (retailer listing, Japanese)
- Daily JW, et al. Equol Decreases Hot Flashes in Postmenopausal Women: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Med Food. 2019
- Jenks BH, et al. A pilot study on the effects of S-equol compared to soy isoflavones on menopausal hot flash frequency. J Womens Health. 2012
- Yoshikata R, et al. Effects of an equol-containing supplement on advanced glycation end products, visceral fat and climacteric symptoms in postmenopausal women: A randomized controlled trial. PLoS One. 2021
- Oyama A, et al. The effects of natural S-equol supplementation on skin aging in postmenopausal women: a pilot randomized placebo-controlled trial. Menopause. 2012
- National Center for Complementary and Integrative Health: Soy
- Food Safety Commission of Japan: Evaluation of soy isoflavones in foods for specified health uses (English report)
- Memorial Sloan Kettering Cancer Center: Soy (About Herbs)
