Red Clover 900 mg Ingredients & Drug Interactions
What is this page for?
First and foremost: checking Red Clover 900 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
Red Clover 900 mg is a dietary supplement by Nature's Answer 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 Red Clover. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Red Clover 900 mg by Nature's Answer
Ask about any prescription or over-the-counter medication and we check it for interactions with Red Clover 900 mg by Nature's Answer — and tell you which ingredient is responsible.
AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Red Clover 900 mg by Nature's Answer
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.
What’s inside
Full disclosure
This product contains one active ingredient: red clover, supplied at 900 mg per capsule. Red clover is a plant that contains phytoestrogens — compounds that act somewhat like the hormone estrogen in the body — and isoflavones, which are believed to be the main active compounds.
The capsule also contains inactive ingredients (fillers and binders): vegetable cellulose, rice flour, and calcium silicate.
Does it work?
Not established
The evidence for red clover isn't yet established for the conditions we have data on. For menopausal symptoms, osteoporosis, osteoarthritis, and androgenic alopecia (hair loss), the research we hold shows insufficient evidence to say whether it works or doesn't.
If you're considering it for one of these, talk with your doctor or pharmacist about what the current science suggests for your situation.
How safe is it?
Well-documented data
Red clover is generally well tolerated short-term in healthy adults, though its estrogen-like effects mean some people need to be cautious. The most common side effects from oral use are muscle pain, nausea, and vaginal spotting — a small number of trial participants reported these.
Because of its estrogen-like activity, red clover is not recommended during pregnancy, and there isn't enough safety information to use it while breastfeeding. If you're pregnant, planning pregnancy, or nursing, talk with your doctor or pharmacist before taking it.
There's also some concern, based on a meta-analysis of clinical trials, that red clover isoflavones might modestly increase breast density on mammograms in premenopausal women — though this wasn't seen in postmenopausal women.
Meds to double-check
Moderate interaction found
Before taking this product, double-check with your doctor or pharmacist if you take tamoxifen (Nolvadex) for cancer, estrogen-containing medications (hormonal birth control, hormone replacement therapy), or methotrexate (Trexall) — these carry Moderate interaction concerns. You should also confirm that it won't affect how your liver processes other medications you may be on, since red clover may theoretically interact with drugs broken down through several liver pathways.
The bottom line
Scorecard at a glanceFully disclosed formula with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.
Red Clover 900 mg might appeal to someone looking for support with menopausal symptoms or bone health, though the evidence isn't yet clear. You should be especially cautious if you take tamoxifen, estrogen therapy, or methotrexate, or if you're pregnant or breastfeeding.
Check your exact medications with your doctor or pharmacist before starting, and talk it over with them to make sure it's right for your situation.
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 Apr 25, 2019.
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
General information
Key facts about Red Clover 900 mg, straight from the product label.
| Brand | Nature's Answer |
|---|---|
| Barcode (UPC) | 083000163142 |
| Net contents | 90 Vegetarian Capsule(s) |
| Market status | On market |
| Date entered into DSLD | Apr 25, 2019 |
| DSLD ID | 184828 |
| Product type | Botanical |
| Supplement form | Capsule |
| Dietary claims / uses | All Other, Structure/Function |
| Intended target group(s) | Vegan, Vegetarian, Kosher, Adult Female (18 - 50 Years), Seniors/Mature (>50 Years) - Women ONLY |
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 Red Clover 900 mg by Nature's Answer, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Red Clover | 900 mg | -- |
Other ingredients: Vegetable Cellulose, Rice Flour, Calcium Silicate
Tap any ingredient to jump to its full detail below.
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.
Brand IP Statement(s)
Discover Nature's Answer and trust the Difference... The True Nature of Our Standards goes way beyond the herb...
Discover Nature's Answer
2017 Nature's Answer
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.
Storage
Store in a cool, dry place.
Seals/Symbols
K Parve
Formula
K Parve
Menopause Support
Trifolium pratense
General Statements
Since 1972
FDA Statement of Identity
Dietary Supplement
Formulation
Vegan
Suggested/Recommended/Usage/Directions
Suggested Use: As a dietary supplement, take two (2) capsules three (3) times a day with food or water.
Precautions
Warning: Keep Out of Reach of Children.
Do not use if safety seal is damaged or missing.
If you are pregnant, nursing, taking any medications, planning any medical procedure or have a medical condition, consult with your healthcare practitioner before use.
General
18314 Rev. 417
Is this label outdated? Report a formula or label change and our pharmacy team will review it.
Red Clover 900 mg by Nature's Answer label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Red Clover 900 mg by Nature's Answer
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size2 Capsule(s) Dosage formCapsule Servings per container45 Amounts shown are per serving.
Red Clover
Interacts with867 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 f...
Red Clover monograph & interactionsOther (inactive) ingredients: Vegetable Cellulose, Rice Flour, Calcium Silicate. These complete the product’s ingredient list but are not active constituents.
Red Clover 900 mg by Nature's Answer Drug Interactions
HelloPharmacist Interaction Report
Red Clover 900 mg by Nature's Answer does interact with several medication types, most notably through its phytoestrogen content.
The most serious concern is with tamoxifen (Nolvadex), a breast cancer medication — red clover's plant estrogens might interfere with how tamoxifen works against tumor cells, though animal evidence is mixed on this point.
Read the full breakdown — every affected drug type, severity by severity
You'll also want to be careful if you're on estrogen therapy (like hormone replacement or birth control pills) or taking methotrexate (Trexall) for conditions like psoriasis or rheumatoid arthritis. Red clover could theoretically reduce how well estrogens work, and there's a case report of someone developing methotrexate toxicity after starting red clover.
Both of these are flagged as Moderate concerns.
Red clover may also affect how your liver breaks down certain other medications — specifically those processed through CYP1A2, CYP2C19, CYP2C9, and CYP3A4 pathways — though a small clinical study found no actual effect in real life. There's also a Minor theoretical concern with blood thinners and antiplatelet drugs (aspirin, warfarin), but clinical research hasn't confirmed this happens in practice.
Altogether, these interactions span 868 individual medications.
We could check red clover thoroughly because it has a full monograph. Run your exact prescriptions through the interaction checker below before you start.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Red Clover 900 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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Red Clover 900 mg interact with 867 drugs. Click any drug to see the details.
1 of the 1 ingredient in Red Clover 900 mg interact with drugs. Each result below shows which ingredient is responsible. Red Clover
Bazedoxifene Acetate, Conjugated EstrogensDuavee
How Bazedoxifene Acetate, Conjugated Estrogens interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Bazedoxifene Acetate, Conjugated Estrogens interactionConjugated EstrogensCenestin, Enjuvia, Premarin, Premarin Vaginal Cream
How Conjugated Estrogens interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Conjugated Estrogens interactionConjugated Estrogens, Medroxyprogesterone AcetatePremplus, Prempro
How Conjugated Estrogens, Medroxyprogesterone Acetate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Conjugated Estrogens, Medroxyprogesterone Acetate interactionConjugated Estrogens, MeprobamatePMB 200, PMB 400
How Conjugated Estrogens, Meprobamate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Conjugated Estrogens, Meprobamate interactionConjugated Estrogens, MethyltestosteronePremarin with Methyltestosterone
How Conjugated Estrogens, Methyltestosterone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Conjugated Estrogens, Methyltestosterone interactionCyproterone Acetate, Ethinyl EstradiolDiane-35, Dianette
How Cyproterone Acetate, Ethinyl Estradiol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Cyproterone Acetate, Ethinyl Estradiol interactionDesogestrel, Ethinyl EstradiolDesogen, Marvelon, Marvelon 21, Marvelon 28, Mircette, Ortho-Cept +2 more
How Desogestrel, Ethinyl Estradiol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates +2 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Desogestrel, Ethinyl Estradiol interactionDrospirenone, EstetrolNextstellis
How Drospirenone, Estetrol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Drospirenone, Estetrol interactionDrospirenone, Ethinyl EstradiolAngeliq, Gianvi, Yasmin
How Drospirenone, Ethinyl Estradiol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Drospirenone, Ethinyl Estradiol interactionEsterified EstrogensEstratab, Menest
How Esterified Estrogens interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Esterified Estrogens interactionEsterified Estrogens, MethyltestosteroneEstratest
How Esterified Estrogens, Methyltestosterone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Esterified Estrogens, Methyltestosterone interactionEstradiolDivigel, Elestrin, Estrace, Estraderm, Estring, Evamist +6 more
How Estradiol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Estradiol interactionEstradiol, MedroxyprogesteroneDivitren
How Estradiol, Medroxyprogesterone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Estradiol, Medroxyprogesterone interactionEstradiol, Norethindrone AcetateActivella
How Estradiol, Norethindrone Acetate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Estradiol, Norethindrone Acetate interactionEstradiol, NorgestimateOrtho-Prefest
How Estradiol, Norgestimate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 1a2 (cyp1a2) Substrates Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Estradiol, Norgestimate interactionEstradiol, ProgesteroneBijuvanda
How Estradiol, Progesterone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Estradiol, Progesterone interactionEstrogenEstrogen
How Estrogen interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Estrogen interactionEstroneOrtho-Est
How Estrone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Estrone interactionEstropipateOgen, Ortho EST
How Estropipate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Estropipate interactionEthiny Estradiol, LevonorgestrelLogynon, Microgynon 30 ED
How Ethiny Estradiol, Levonorgestrel interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Ethiny Estradiol, Levonorgestrel interactionEthinyl EstradiolEstinyl
How Ethinyl Estradiol interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Cytochrome P450 3a4 (cyp3a4) Substrates +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol interactionEthinyl Estradiol, DesogestrelApri, Cesia, Cyclessa, Gedarel, Kariva, Linessa +4 more
How Ethinyl Estradiol, Desogestrel interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 2c9 (cyp2c9) Substrates, Estrogens +2 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP2C9; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol, Desogestrel interactionEthinyl Estradiol, DrospirenoneYaz
How Ethinyl Estradiol, Drospirenone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol, Drospirenone interactionEthinyl Estradiol, Ethynodiol DiacetateDemulen 1/35, Demulen 1/50, Demulen Compack, Kelnor 1/35, Zovia, Zovia 1/35 +1 more
How Ethinyl Estradiol, Ethynodiol Diacetate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Ethinyl Estradiol, Ethynodiol Diacetate interactionEthinyl Estradiol, LevonorgestrelAlesse, Alesse 21, Alesse 28, Aviane, Enpresse, Jolessa +18 more
How Ethinyl Estradiol, Levonorgestrel interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol, Levonorgestrel interactionEthinyl Estradiol, NorethindroneAranelle, Brevicon, Brevicon .5/35 21 day, Brevicon .5/35 28 day, Brevicon 1/35 21 day, Brevicon 1/35 28 day +50 more
How Ethinyl Estradiol, Norethindrone interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Ethinyl Estradiol, Norethindrone interactionEthinyl Estradiol, Norethindrone, Ferrous FumarateEstrostep Fe, Femcon FE, Junel Fe 1.5/30, Loestrin Fe, Loestrin Fe 1.5/30, Loestrin Fe 1/20 +3 more
How Ethinyl Estradiol, Norethindrone, Ferrous Fumarate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 1a2 (cyp1a2) Substrates, Estrogens +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP1A2; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol, Norethindrone, Ferrous Fumarate interactionEthinyl Estradiol, NorgestimateCilest, Mononessa, Ortho Tri-Cyclen 28, Ortho Tri-Cyclen Lo, Ortho Tri-Cylcen, Ortho-Cyclen +5 more
How Ethinyl Estradiol, Norgestimate interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Ethinyl Estradiol, Norgestimate interactionEthinyl Estradiol, NorgestrelCryselle, Lo/Ovral, Low-Ogestrel, Ogestrel 0.5/50, Ovral
How Ethinyl Estradiol, Norgestrel interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverCytochrome P450 3a4 (cyp3a4) Substrates, Cytochrome P450 1a2 (cyp1a2) Substrates +1 Moderate
Interaction Summary
Theoretically, red clover might increase levels of drugs metabolized by CYP3A4; however, a small clinical study found no effect.
Read the full Red Clover + Ethinyl Estradiol, Norgestrel interactionEthinyl Estradiol, LevonogestrelLybrel
How Ethinyl Estradiol, Levonogestrel interacts with Red Clover 900 mg — through 1 ingredient. Tap an ingredient for the detail:
Red CloverEstrogens, Cytochrome P450 3a4 (cyp3a4) Substrates +1 Moderate
Interaction Summary
Theoretically, concomitant use of large amounts of red clover might interfere with estrogen therapy.
Read the full Red Clover + Ethinyl Estradiol, Levonogestrel interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Red Clover 900 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.
Red Clover
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.
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.
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.
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.
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.
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.
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.
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.
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.
Brand information
Manufacturer and brand details for Red Clover 900 mg, from the product label.
Nature's Answer
See all Nature's Answer products- Name
- Nature's Answer
- Street Address
- 85 Commerce Drive
- City
- Hauppauge
- State
- NY
- ZipCode
- 11788
- Phone Number
- (800) 439-2324
- Web Address
- www.naturesanswer.com
Red Clover 900 mg by Nature's Answer: Common Questions
Does Red Clover 900 mg by Nature's Answer interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Can I take red clover if I'm on birth control or hormone replacement?
What are the most common side effects?
Is red clover safe during pregnancy?
Can I take red clover while breastfeeding?
Does this product work for hot flashes or menopause?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Red Clover 900 mg is safe with your meds?
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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.
The Full Monographs Behind Red Clover 900 mg’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
Red Clover 900 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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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
- Kurzer MS, Xu X. Dietary phytoestrogens. Annu Rev Nutr 1997;17:353-81. PubMed
- 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
- 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
- This P, De La Rochefordiere A, Clough K, et al. Phytoestrogens after breast cancer. Endocr Relat Cancer 2001;8:129-34. PubMed
- 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.
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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
- 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.
- 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
- 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
- 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
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.
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