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Dietary supplement

Isoflavone-250 with Genistein Ingredients & Drug Interactions

by Douglas Laboratories

Capsule Category: Botanical
Most serious interaction: Moderate
The interaction bottom line Most serious interaction: Moderate

Isoflavone-250 with Genistein is a dietary supplement by Douglas Laboratories 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 Isoflavone plant extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Isoflavone-250 with Genistein by Douglas Laboratories

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

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 6 active ingredients.
  • “Isoflavone plant extract” is listed as a grouped ingredient — the label gives one combined amount (250 mg) without saying how much of each component you get.

This product has 6 ingredients total, of which the active components are isoflavones derived from red clover—specifically Daidzin, Glycitin, Genistin, Genistein, Daidzein, and Glycitein. These are plant-derived compounds (phytoestrogens) that mimic estrogen activity in the body.

The inactive ingredients are microcrystalline cellulose, gelatin, silica, and vegetable stearate, which serve as capsule material and binders.

Does it work?

Not established
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 established

The graded evidence we hold for these ingredients covers different conditions than the ones this product is marketed for, so there's no established rating for its stated use — see Red Clover's own graded uses on its monograph.

Why this rating?
  • The label markets this product for: menopause and women's health support.
  • We looked for evidence on: Menopausal symptoms, Breast cancer-related hot flashes, Hyperlipidemia, Osteoporosis, bone health, cardiovascular health.
  • The closest evidence on file: Red Clover is rated "Insufficient Reliable Evidence To Rate" for Osteoporosis (Natural Medicines).
  • Also on file: Red Clover is rated "Insufficient Reliable Evidence To Rate" for Breast cancer-related hot flashes, Hyperlipidemia, Menopausal symptoms.

The evidence for what this product can do isn't established in our data. The documented effectiveness ratings for the conditions it's marketed toward—androgenic alopecia (male-pattern hair loss), menopausal symptoms, osteoarthritis, and osteoporosis—all show insufficient reliable evidence to rate.

That means the research so far hasn't been strong enough to confirm whether it actually works for these purposes.

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.

Short-term, this product is generally well tolerated in healthy adults, but the estrogen-like effects of the isoflavones call for caution in certain people. The most common side effects reported are muscle pain (myalgia), nausea, and vaginal spotting.

There's been some concern about whether long-term use might modestly increase mammographic breast density in premenopausal women, though studies in postmenopausal women haven't shown the same effect. Avoid this product during pregnancy—the estrogen-like activity and lack of safety data make it unsafe.

There isn't enough safety information to know either way while breastfeeding; talk with your doctor or pharmacist for personalized advice.

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.

Check with your pharmacist before taking this product if you use estrogens (birth control, hormone replacement therapy), methotrexate, or tamoxifen—all Moderate-severity concerns. Also double-check if you take drugs metabolized by your liver's CYP1A2, CYP2C19, CYP2C9, or CYP3A4 enzymes, or blood thinners and antiplatelet medications, though the clinical significance of those Minor interactions remains unclear.

Use the medication checker below with your complete list.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

This product is an isoflavone blend with real medication interactions, particularly with estrogens, methotrexate, and tamoxifen. If you're on any of those or take medications metabolized by your liver, check with us first.

Even if you're not on those drugs, the estrogen-like effects mean you should talk to your pharmacist about whether it's right for you, especially if you have any history of hormone-sensitive conditions.

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

Assessment coverage: 2 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2020.

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 Isoflavone-250 with Genistein, straight from the product label.

Brand Douglas Laboratories
Barcode (UPC) 310539006504
Net contents 60 Capsule(s)
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 232054
Product type Botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult Female (18 - 50 Years), Menopause, Seniors/Mature (>50 Years) - Women ONLY, Gluten Free
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 Isoflavone-250 with Genistein by Douglas Laboratories, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
60
UPC/BARCODE
310539006504
IngredientAmount% DV
Daidzin0 NP--
Glycitin0 NP--
Genistin0 NP--
Genistein0 NP--
Daidzein0 NP--
Glycitein0 NP--
Isoflavone plant extract250 mg--

Other ingredients: Microcrystalline Cellulose, Gelatin, Silica, Vegetable Stearate

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.
Suggested/Recommended/Usage/Directions

Suggested Usage: As a dietary supplement, adults take 1 capsule daily or as directed by your health professional.

Precautions

Warning: If you are pregnant, nursing, have any health condition or taking any medication, consult your health professional before using this product.

Keep out of reach of children.

Use only if safety seal is intact.

Contains: Soy

Storage

Store in a cool, dry place.

Formulation

Gluten-free, Non-GMO

FDA Disclaimer Statement

This statement has not been evaluated by the Food and Drug Administration. This product is not intended to diagnose, treat, cure, or prevent any disease.

General Statements

Scan to learn about our manufacturing excellence Contents may not fill package in order to accommodate required labeling. Please rely on stated quantity.

FDA Statement of Identity

Dietary Supplement

Formula

Support for menopause and bone health

See for yourself

Isoflavone-250 with Genistein by Douglas Laboratories label

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

What’s inside

The Ingredients in Isoflavone-250 with Genistein by Douglas Laboratories

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container60 Amounts shown are per serving.

Isoflavone plant extract

Interacts with
867 drugs
250 mg per serving Form: Isoflavone Standardized Plant Extract 40%

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...

Isoflavone plant extract monograph & interactions

Other (inactive) ingredients: Microcrystalline Cellulose, Gelatin, Silica, Vegetable Stearate. These complete the product’s ingredient list but are not active constituents.

Interaction report

Isoflavone-250 with Genistein by Douglas Laboratories Drug Interactions

Want to check YOUR meds against Isoflavone-250 with Genistein?

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

Each ingredient & the kinds of drugs it affects

For each ingredient in Isoflavone-250 with Genistein 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.

Isoflavone plant extract9 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
The maker

Brand information

Manufacturer and brand details for Isoflavone-250 with Genistein, from the product label.

Douglas Laboratories

See all Douglas Laboratories products
Name
Douglas Laboratories
Street Address
600 Boyce Road
City
Pittsburgh
State
PA
ZipCode
15205
Phone Number
1.800.245.4440
Web Address
www.douglaslabs.com
Pharmacist Counseling Corner

Isoflavone-250 with Genistein by Douglas Laboratories: Common Questions

Does Isoflavone-250 with Genistein by Douglas Laboratories interact with any medications?
Yes. Based on its ingredients, Isoflavone-250 with Genistein 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?
Isoflavone-250 with Genistein 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.
Can I take this while pregnant?
No, avoid it during pregnancy. The estrogen-like effects and lack of safety data make it unsafe. Talk with your doctor about alternatives if you're pregnant or planning to become pregnant.
What are the most common side effects?
Muscle pain, nausea, and vaginal spotting have been reported. One product in this family was also associated with headache, though no more often than placebo.
Does this really work for hot flashes or bone health?
We don't have enough reliable evidence in our data to say whether it works for menopausal symptoms, osteoporosis, osteoarthritis, or hair loss. The research so far hasn't been strong enough to confirm benefit.
Is this safe to take long-term?
Short-term use is generally well tolerated, but we have limited long-term safety data. There's some concern about potential effects on breast tissue in premenopausal women. Talk with your pharmacist about how long you plan to use it and whether that's appropriate for you.
What is genistein, and why is it in this product?
Genistein is a plant compound (phytoestrogen) from red clover that mimics estrogen activity in your body. It's included because of its potential effects on menopausal symptoms and bone health, though the evidence isn't yet strong enough to confirm it works.

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

Not sure if Isoflavone-250 with Genistein is safe with your meds?

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Ask a pharmacist

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.

Isoflavone-250 with Genistein label
Go deeper

The Full Monographs Behind Isoflavone-250 with Genistein’s Ingredients

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

Sources

Sources & How We Checked

Isoflavone-250 with Genistein'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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