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Dietary supplement

Genistein 125 mg Ingredients & Drug Interactions

by Swanson Ultra

Genistein 125 mg label
See full label image
Capsule Category: Non-nutrient/non-botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Genistein 125 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Genistein 125 mg is a dietary supplement by Swanson Ultra with 1 active ingredient. Its ingredients are commonly taken for menopause symptoms (hot flashes), high cholesterol, bone health/osteoporosis.Based on those ingredients, 867 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Genistein. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Genistein 125 mg by Swanson Ultra

Ask about any prescription or over-the-counter medication and we check it for interactions with Genistein 125 mg by Swanson Ultra — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Genistein 125 mg by Swanson Ultra

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains a single active ingredient: genistein 125 mg, an isoflavone extracted from red clover. The capsule also contains inactive ingredients — hypromellose (the capsule material itself), brown rice flour, L-leucine, and silica — which help deliver the dose but don't contribute to the supplement's intended effects.

Does it work?

Couldn't assess
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed
Not assessable

This is a single-ingredient Red Clover product and its label doesn't state a use — see Red Clover's own graded uses on its monograph.

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.

The evidence on genistein and red clover for the uses we have data on — androgenic alopecia (male or female pattern hair loss), menopausal symptoms, osteoarthritis, and osteoporosis — is insufficient to make a reliable rating. You won't find a solid yes or no for any of these conditions in the research we hold.

The evidence, ingredient by ingredient Red Clover

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Red clover is generally well tolerated over the short term in healthy adults, though its estrogen-like activity means certain people need to be cautious. The most common side effects reported are muscle pain, nausea, and vaginal spotting.

There's also been some concern about whether isoflavones increase breast density on mammograms in premenopausal women, though the long-term clinical meaning of this isn't clear. During pregnancy, the safety data advises against it because of genistein's estrogen-like effects and lack of safety studies.

While breastfeeding, there isn't enough information — talk with your doctor or pharmacist to weigh whether it's right for you.

Side effects, ingredient by ingredient Red Clover

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Red Clover.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 868 individual medications appear in the full list. A big number alone doesn't make a product dangerous — what matters is whether YOUR medication is on it, so run yours through the interaction checker on this page.

Before you take this, check if you're on tamoxifen, estrogens (including birth control), or methotrexate — these carry Moderate-severity concerns. Also run any other prescription medications through the checker, since red clover may theoretically affect how your liver processes many different drugs, though real-world effects are unclear.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with no assessable stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Genistein may be worth considering if you're interested in red clover's traditional uses, but it's not your move if you take tamoxifen, estrogens, or methotrexate. Pregnant people and those breastfeeding should skip it.

Check your medications with the tool below before you start.

Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI

Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Sep 21, 2018.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Genistein 125 mg, straight from the product label.

Brand Swanson Ultra
Barcode (UPC) 087614028729
Net contents 60 Veggie Capsule(s)
Market status On market
Date entered into DSLD Sep 21, 2018
DSLD ID 180972
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other
Intended target group(s) Vegetarian, Adult (18 - 50 Years)
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Genistein 125 mg by Swanson Ultra, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Veggie Capsule(s)
Maximum serving Sizes:
1 Veggie Capsule(s)
UPC/BARCODE
087614028729
IngredientAmount% DV
Genistein125 mg--

Other ingredients: Hypromellose, Brown Rice Flour, L-Leucine, Silica

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
General Statements

The Most Advanced Nutrition Technology Veg caps

To reorder, call toll free 1-800-437-4148 or visit our website at www.swansonvitamins.com

Formulation

Soy-free

V Vegetarian formula

Formula

Genistein from Sophora Japonica

FDA Statement of Identity

Dietary Supplement

Seals/Symbols

Guaranteed purity & potency V Vegetarian formula

Precautions

Do not use if seal is broken.

Keep out of reach of children.

Warning: Do not take this product if you are pregnant or nursing. Consult your healthcare provider before use if you are taking any prescription medications or have a medical condition.

Discontinue use if unusual symptoms occur.

Storage

Store in a cool, dry place.

Suggested/Recommended/Usage/Directions

Suggested Use: As a dietary supplement, take one veggie capsule per day with water.

General

SWU872 Rev 0 04 03 17

Is this label outdated? Report a formula or label change and our pharmacy team will review it.

See for yourself

Genistein 125 mg by Swanson Ultra label

The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.

Genistein 125 mg label

Label images are published by the NIH Dietary Supplement Label Database for the version of this product on file. Always read your actual product label.

View the full label (PDF)
What’s inside

The Ingredients in Genistein 125 mg by Swanson Ultra

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Veggie Capsule(s) Dosage formCapsule Amounts shown are per serving.

Genistein

Interacts with
867 drugs
125 mg per serving Form: Sophora japonica

Red clover is a plant rich in isoflavones (plant compounds with weak estrogen-like activity) that is most often used for menopause symptoms like hot f...

Genistein monograph & interactions

Other (inactive) ingredients: Hypromellose, Brown Rice Flour, L-Leucine, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Genistein 125 mg by Swanson Ultra Drug Interactions

Want to check YOUR meds against Genistein 125 mg?

Ask about interactions with your drugs in plain English — “Can I take it with lisinopril?” — and we find you the answer in seconds, ingredient by ingredient.

 Go to the checker
867Drugs
44 Moderate 823 Minor

Ingredients driving the most interactions

Genistein 867

Individual Drug Interactions

The ingredients in Genistein 125 mg interact with 867 drugs. Click any drug to see the details.

1 of the 1 ingredient in Genistein 125 mg interact with drugs. Each result below shows which ingredient is responsible. Genistein

Each ingredient & the kinds of drugs it affects

For each ingredient in Genistein 125 mg with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.

Genistein9 drug types · 867 drugs

Estrogens

Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Red clover contains phytoestrogens which might have estrogenic activity in some people. Theoretically, red clover might compete for estrogen receptors and interfere with estrogen-containing drug therapy.

Likelihood Probable Evidence D
Methotrexate (Trexall, Others)

Theoretically, red clover might increase the risk of methotrexate toxicity.
In a case report, a 52-year-old female receiving weekly methotrexate injections for psoriasis developed symptoms of methotrexate toxicity, including severe vomiting and epigastric pain, after three days of taking red clover 430 mg daily. Toxicity resolved after red clover was discontinued. However, no liver function tests or methotrexate levels were reported.

Likelihood Possible Evidence D
Tamoxifen (Nolvadex)

Theoretically, the phytoestrogens in red clover might interfere with tamoxifen.
In vitro and animal research suggests that genistein, a constituent of red clover, might antagonize the antitumor effects of tamoxifen. However, there is some evidence from an animal study that red clover does not reduce the efficacy of tamoxifen. Until more is known, tell patients taking tamoxifen to avoid red clover.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Although some laboratory research suggests that red clover may have anticoagulant and antiplatelet activity, clinical research has not shown this effect.
In vitro research suggests that genistein in red clover has antiplatelet effects, and historically, red clover was thought to have anticoagulant effects due to its coumarin content. However, some experts state that this is unlikely as most natural coumarins have not been shown to have anticoagulant effects, and their content in red clover is low. Additionally, some clinical research in postmenopausal patients found no effect on coagulation or prothrombin time with the use of red clover flowering tops 378 mg daily for 12 months or red clover isoflavone (Rimostil) 50 mg daily for 2 years.

Likelihood Unlikely Evidence B
Caffeine

Theoretically, soy might reduce the clearance of caffeine; however, a small clinical study found no effect.
Red clover contains genistein. Taking genistein 1 gram daily for 14 days seems to inhibit caffeine clearance and metabolism in healthy females. However, this effect does not seem to occur with the lower amounts of genistein found in red clover. A clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of caffeine.

Likelihood Unlikely Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
In vitro evidence shows that red clover inhibits CYP1A2. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of caffeine, a CYP1A2 probe substrate.

Likelihood Unlikely Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, red clover might increase the levels and clinical effects of drugs metabolized by CYP2C19.
In vitro evidence suggests that red clover weakly inhibits CYP2C19. This interaction has not been reported in humans.

Likelihood Unlikely Evidence D
Cytochrome P450 2C9 (Cyp2C9) Substrates

Theoretically, red clover might increase levels of drugs metabolized by CYP2C9; however, a small clinical study found no effect.
In vitro evidence suggests that red clover might inhibit CYP2C9. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of tolbutamide, a CYP2C9 probe substrate.

Likelihood Unlikely Evidence D
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
In vitro evidence shows that red clover might inhibit CYP3A4 isoenzymes. However, a clinical study in healthy postmenopausal individuals shows that taking red clover capsules standardized to contain 60 mg isoflavones twice daily for 14 days does not affect the pharmacokinetics of alprazolam, a CYP3A4 probe substrate.

Likelihood Unlikely Evidence B
Genistein full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Genistein 125 mg, from the product label.

Swanson Ultra

See all Swanson Ultra products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
www.swansonvitamins.com
Pharmacist Counseling Corner

Genistein 125 mg by Swanson Ultra: Common Questions

Does Genistein 125 mg by Swanson Ultra interact with any medications?
Yes. Based on its ingredients, Genistein 125 mg has a known interaction with 867 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Genistein 125 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
What is genistein, and where does it come from?
Genistein is an isoflavone, a plant compound with estrogen-like activity, extracted from red clover. It's the active ingredient in this supplement.
Can I take this if I'm pregnant or breastfeeding?
During pregnancy, the data advises against it because of its estrogen-like effects and lack of safety studies. While breastfeeding, there isn't enough safety information either — talk with your doctor or pharmacist to decide what's right for you.
What side effects might I experience?
The most commonly reported are muscle pain, nausea, and vaginal spotting. Headache has also been reported with some red clover products, though at rates similar to placebo. Red clover is generally well tolerated, but its estrogen-like activity calls for caution in certain people.
Does genistein actually work for hair loss, menopause, or arthritis?
The evidence we hold doesn't establish reliable effectiveness for any of those uses — the research is insufficient to rate it one way or the other.
Why do I need to check my medications if you say clinical studies found no effect?
The in-lab evidence shows red clover may inhibit several drug-metabolizing enzymes, but small clinical studies haven't detected a real-world effect in some cases. That doesn't mean none exists, especially in your specific situation or with other drugs. Your exact medications and medical history matter, so check them with the tool.

Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Genistein 125 mg label
Go deeper

The Full Monographs Behind Genistein 125 mg’s Ingredients

Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.

Herb & supplement monograph

Red Clover

Interacts with 867 drugs

Red clover is a plant rich in isoflavones (plant compounds with weak estrogen-like activity) that is most often used for menopause symptoms like hot flashes. The evidence is mixed and genera...

Read the full Red Clover monograph →
Sources

Sources & How We Checked

Genistein 125 mg's label data comes from the NIH Dietary Supplement Label Database; the ingredient interaction data is from the Natural Medicines database, reviewed by our pharmacists.

Content is written and reviewed by licensed HelloPharmacist pharmacists. See our data sources and editorial standards for how this information is built and checked.

The 24 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Red Clover 24 references
  1. Kurzer MS, Xu X. Dietary phytoestrogens. Annu Rev Nutr 1997;17:353-81. PubMed
  2. Electronic Code of Federal Regulations. Title 21. Part 182 -- Substances Generally Recognized As Safe. Available at: https://www.accessdata.fda.gov/scripts/cdrh/cfdocs/cfcfr/CFRSearch.cfm?CFRPart=182
  3. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  4. This P, De La Rochefordiere A, Clough K, et al. Phytoestrogens after breast cancer. Endocr Relat Cancer 2001;8:129-34. PubMed
  5. Tice J, Cummings SR, Ettinger B, et al. Few adverse effects of two red clover extracts rich in phytoestrogens: a multicenter, placebo-controlled trial. Alt Ther 2001;7:S33.
  6. Ingram DM, Hickling C, West L, et al. A double-blind randomized controlled trial of isoflavones in the treatment of cyclical mastalgia. The Breast 2002;11:170-4. PubMed
  7. Unger M, Frank A. Simultaneous determination of the inhibitory potency of herbal extracts on the activity of six major cytochrome P450 enzymes using liquid chromatography/mass spectrometry and automated online extraction. Rapid Commun Mass Spectrom 2004;1 PubMed
  8. Cheong JL, Bucknall R. Retinal vein thrombosis associated with a herbal phytoestrogen preparation in a susceptible patient. Postgrad Med J 2005;81:266-7.. PubMed
  9. Geller SE, Shulman LP, van Breemen RB, et al. Safety and efficacy of black cohosh and red clover for the management of vasomotor symptoms: a randomized controlled trial. Menopause 2009;16:1156-66. PubMed
  10. Hidalgo LA, Chedraui PA, Morocho N, et al. The effect of red clover isoflavones on menopausal symptoms, lipids and vaginal cytology in menopausal women: a randomized, double-blind, placebo-controlled study. Gynecol Endocrinol 2005;21(5):257-264. PubMed
  11. Campbell MJ, Woodside JV, Honour JW, et al. Effect of red clover-derived isoflavone supplementation on insulin-like growth factor, lipid and antioxidant status in healthy female volunteers: a pilot study. Eur J Clin Nutr 2004;58(1):173-179. PubMed
  12. Guerrero JA, Lozano ML, Castillo J, et al. Flavonoids inhibit platelet function through binding to the thromboxane A2 receptor. J Thromb Haemost 2005;3(2):369-376. PubMed
  13. Kondo K, Suzuki Y, Ikeda Y, Umemura K. Genistein, an isoflavone included in soy, inhibits thrombotic vessel occlusion in the mouse femoral artery and in vitro platelet aggregation. Eur J Pharmacol 2002;455(1):53-57. PubMed
  14. Polini N, Rauschemberger MB, Mendiberri J, et al. Effect of genistein and raloxifene on vascular dependent platelet aggregation. Mol Cell Endocrinol 2007;267(1-2):55-62. PubMed
  15. Wuttke W, Jarry H, Seidlova-Wuttke D. Plant-derived alternative treatments for the aging male: facts and myths. Aging Male 2010;13(2):75-81. PubMed
  16. Villaseca P. Non-estrogen conventional and phytochemical treatments for vasomotor symptoms: what needs to be known for practice. Climacteric 2012;15(2):115-124. PubMed
  17. Chen, Y., Xiao, C. Q., He, Y. J., Chen, B. L., Wang, G., Zhou, G., Zhang, W., Tan, Z. R., Cao, S., Wang, L. P., and Zhou, H. H. Genistein alters caffeine exposure in healthy female volunteers. Eur.J Clin.Pharmacol. 2011;67(4):347-353. PubMed
  18. Friedman, J. A., Taylor, S. A., McDermott, W., and Alikhani, P. Multifocal and recurrent subarachnoid hemorrhage due to an herbal supplement containing natural coumarins. Neurocrit.Care 2007;7(1):76-80. PubMed
  19. Hooper, L., Madhavan, G., Tice, J. A., Leinster, S. J., and Cassidy, A. Effects of isoflavones on breast density in pre- and post-menopausal women: a systematic review and meta-analysis of randomized controlled trials. Hum.Reprod.Update. 2010;16(6):745-7 PubMed
  20. Orr A and Parker R. Red clover causing symptoms suggestive of methotrexate toxicity in a patient on high-dose methotrexate. Menopause Int. 2013;19(3):133-134. PubMed
  21. Clifton-Bligh PB, et al. Red cover isoflavones enriched with formononetin lower serum LDL cholesterol- a randomized, double-blind, placebo-controlled trial. Eur J Clin Nutr. 2015;69(1):134-142.
  22. Risk assessment for peri- and post-menopausal women taking food supplements containing isolated isoflavones. EFSA Panel on Food Additives and Nutrient Sources added to Food (ANS). 2015. DOI
  23. Ferraris C, Ballestra B, Listorti C, et al. Red clover and lifestyle changes to contrast menopausal symptoms in premenopausal patients with hormone-sensitive breast cancer receiving tamoxifen. Breast Cancer Res Treat 2020;180(1):157-65. doi: 10.1007/s1054 PubMed
  24. Chen L, Choi J, Leonard SW, et al. No Clinically Relevant Pharmacokinetic Interactions of a Red Clover Dietary Supplement with Cytochrome P450 Enzymes in Women. J Agric Food Chem. 2020;68(47):13929-13939. PubMed

See these in context on the Red Clover monograph →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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