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Dietary supplement

Periwinkle/Red Clover Extract Ingredients & Drug Interactions

by MBi Nutraceuticals

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

Periwinkle/Red Clover Extract is a dietary supplement by MBi Nutraceuticals with 2 active ingredients. Its ingredients are commonly taken for menopause symptoms (hot flashes), high cholesterol, bone health/osteoporosis.Based on those ingredients, 991 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Red Clover, Periwinkle. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

HelloPharmacist Scorecard of Periwinkle/Red Clover Extract by MBi Nutraceuticals

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

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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains 2 active ingredients: red clover and periwinkle, both delivered in liquid form. Red clover is a plant source of isoflavones—compounds with estrogen-like activity in the body.

Periwinkle contains vinca alkaloids, potent plant compounds that affect blood vessel function and other systems. The liquid also includes inactive ingredients (deionized water, ethanol, and glycerin) as the base.

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.

Why this rating?
  • The label markets this product for: blood purification and respiratory/skin health.
  • We looked for evidence on: Hyperlipidemia, Menopausal symptoms, Osteoporosis, asthma, bronchitis, psoriasis.
  • 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 Hyperlipidemia, Menopausal symptoms.

Evidence for red clover's effectiveness is insufficient to rate it for any of the claimed uses we hold data on—androgenic alopecia (hair loss), menopausal symptoms, osteoarthritis, and osteoporosis. No effectiveness ratings are documented for periwinkle in our data.

If you're considering this product for a specific condition, talk with your doctor or pharmacist about whether the evidence supports its use for your situation.

The evidence, ingredient by ingredient Red Clover Periwinkle

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Red clover is generally well tolerated short-term in healthy adults, though its estrogen-like activity requires caution in certain people. The most commonly reported side effects from red clover are muscle pain, nausea, and vaginal spotting.

There's theoretical concern that red clover isoflavones might increase breast density in premenopausal women, though studies have not confirmed a clinical risk. Periwinkle, by contrast, is regarded as unsafe for use—its vinca alkaloids can cause liver, kidney, and nerve damage at higher doses, and even at typical doses may cause stomach upset, skin flushing, and low blood pressure.

For pregnancy, red clover safety data is limited; the ingredient is listed as possibly unsafe due to its estrogen-like effects. Periwinkle is considered unsafe in pregnancy.

Neither ingredient has enough safety data for breastfeeding, so both should be avoided.

Side effects, ingredient by ingredient Red Clover Periwinkle

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?
  • 2 of the 2 matched ingredients can interact with medications — Red Clover, Periwinkle.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 992 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 taking this product, check with your doctor or pharmacist if you take methotrexate, estrogen-containing medications, tamoxifen, or blood pressure medications—these carry Moderate-severity interaction risks. Also flag any drugs your liver metabolizes (CYP1A2, CYP2C19, CYP2C9, or CYP3A4 substrates) and any blood thinners or antiplatelet drugs, though human evidence for the latter is limited.

Check your own medication Run your meds through the checker above

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.

This product combines two ingredients with limited evidence for effectiveness and notable safety concerns, especially periwinkle's potential for toxicity. If you take methotrexate, blood pressure medications, hormone therapy, tamoxifen, or any liver-metabolized drug, you need to review this product with your own doctor or pharmacist before starting.

Pregnant or breastfeeding women should not use it.

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

Assessment coverage: 2 of 2 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 Periwinkle/Red Clover Extract, straight from the product label.

Brand MBi Nutraceuticals
Net contents 2 fl. Oz.
Market status On market
Date entered into DSLD Aug 23, 2020
DSLD ID 231775
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Children 4 or More Years of Age, 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 Periwinkle/Red Clover Extract by MBi Nutraceuticals, 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:
25 Drop(s)
Maximum serving Sizes:
25 Drop(s)
Servings per container
60
IngredientAmount% DV
Red Clover100 mg--
Periwinkle100 mg--

Other ingredients: deionized Water, Ethanol, Glycerin

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.
Formulation

Periwinkle/Red Clover Extract is made from imported and domestic herbs. Purifies the blood, treats asthma, bronchitis, psoriasis, and more.

Phyto-Fresh Liquid Herbal Therapy

Suggested/Recommended/Usage/Directions

Recommendation: Adults or children four or more years of age; take 25 drops 3 or 4 times per day or as directed by your health care professional.

General Statements

Shake well before using.

Precautions

Warning: Keep out of the reach of children.

If pregnant or nursing, consult your physician before using this product.

If tamper resistant seals are broken do not use this product.

See for yourself

Periwinkle/Red Clover Extract by MBi Nutraceuticals label

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

What’s inside

The Ingredients in Periwinkle/Red Clover Extract by MBi Nutraceuticals

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size25 Drop(s) Dosage formLiquid Servings per container60 Amounts shown are per serving.

Most supplement products combine several ingredients, and a medication can interact with the product through any one of them. Each ingredient below shows whether it has known drug interactions.

Red Clover

Interacts with
867 drugs
100 mg per serving

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 & interactions

Periwinkle

Interacts with
172 drugs
100 mg per serving

Periwinkle (Vinca minor) is a flowering plant whose alkaloids are the source of vinpocetine, a compound marketed for memory and brain circulation. Evi...

Periwinkle monograph & interactions

Other (inactive) ingredients: Deionized Water, Ethanol, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Periwinkle/Red Clover Extract by MBi Nutraceuticals Drug Interactions

Want to check YOUR meds against Periwinkle/Red Clover Extract?

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
991Drugs
216 Moderate 775 Minor

Ingredients driving the most interactions

Each ingredient & the kinds of drugs it affects

For each ingredient in Periwinkle/Red Clover Extract with known interactions, here are the types of medications they can affect. Open any type for the detail — or search your exact drug in the checker above.

Red Clover9 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

Periwinkle1 drug type · 172 drugs

Antihypertensive Drugs

Theoretically, taking periwinkle may increase the effects of antihypertensive drugs due to the hypotensive activity of vincamine, a constituent of periwinkle.

Likelihood Probable Evidence D
The maker

Brand information

Manufacturer and brand details for Periwinkle/Red Clover Extract, from the product label.

MBi Nutraceuticals

See all MBi Nutraceuticals products
Name
MBi Nutraceuticals
City
Lindon
State
UT
ZipCode
84042
Phone Number
800-321-3740
Pharmacist Counseling Corner

Periwinkle/Red Clover Extract by MBi Nutraceuticals: Common Questions

Does Periwinkle/Red Clover Extract by MBi Nutraceuticals interact with any medications?
Yes. Based on its ingredients, Periwinkle/Red Clover Extract has a known interaction with 991 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Periwinkle/Red Clover Extract contains 2 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is 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 if I'm pregnant or breastfeeding?
No. Periwinkle is unsafe during pregnancy due to its potent alkaloids. Red clover's safety in pregnancy is unclear because of its estrogen-like effects and limited data. Neither ingredient has enough safety information for breastfeeding. Talk with your doctor or pharmacist about alternatives.
What side effects might I experience?
Red clover most commonly causes muscle pain, nausea, and vaginal spotting. Periwinkle can cause stomach upset, skin flushing, and low blood pressure—and at higher doses poses risk of serious liver, kidney, and nerve damage. If you experience any of these, stop and contact your healthcare provider.
Does this product actually work for hair loss, hot flashes, joint pain, or bone health?
The evidence isn't established in our data. For red clover and these conditions—androgenic alopecia, menopausal symptoms, osteoarthritis, and osteoporosis—we have insufficient reliable evidence to rate effectiveness. Ask your doctor whether there's a stronger evidence base for these uses elsewhere or whether other options might be better.
Why are there so many medications listed as interacting with this?
Red clover inhibits several liver enzymes that metabolize hundreds of drugs. That means if you're on any medication cleared by those pathways—anything from certain antibiotics to heart drugs to antidepressants—red clover could theoretically change its levels. That's why it's important to check your specific medications before starting.
Is this safe if I don't take any prescription drugs?
Red clover alone is generally well tolerated short-term in healthy adults. Periwinkle, however, is regarded as unsafe because its alkaloids can damage your liver, kidneys, and nerves even at normal doses. If you're considering this product, have a conversation with your pharmacist or doctor about whether the periwinkle component makes sense for you.

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.

Periwinkle/Red Clover Extract label
Sources

Sources & How We Checked

Periwinkle/Red Clover Extract'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 29 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 →

Periwinkle 5 references
  1. Blumenthal M, ed. The Complete German Commission E Monographs: Therapeutic Guide to Herbal Medicines. Trans. S. Klein. Boston, MA: American Botanical Council, 1998.
  2. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  3. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  4. Gruenwald J, Brendler T, Jaenicke C. PDR for Herbal Medicines. 1st ed. Montvale, NJ: Medical Economics Company, Inc., 1998.
  5. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

See these in context on the Periwinkle 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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