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Dietary supplement

Ipriflavone 300 mg Ingredients & Drug Interactions

by NOW

Ipriflavone 300 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 Ipriflavone 300 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

Ipriflavone 300 mg is a dietary supplement by NOW with 1 active ingredient. Its ingredients are commonly taken for bone density and osteoporosis, postmenopausal bone loss, athletic performance.Based on those ingredients, 391 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Ipriflavone. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Ipriflavone 300 mg by NOW

Ask about any prescription or over-the-counter medication and we check it for interactions with Ipriflavone 300 mg by NOW — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Ipriflavone 300 mg by NOW

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 Aug 13, 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 one active ingredient: ipriflavone, a compound structurally similar to a plant estrogen. The capsule itself is made from bovine gelatin, with cellulose and magnesium stearate as inactive ingredients to hold it together and aid processing.

Does it work?

Strong evidence
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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: support bone health and metabolism.
  • We looked for evidence on: Osteoporosis, Bone density, Postmenopausal bone loss, Bone remodeling.
  • The strongest evidence on file: Ipriflavone is rated "Likely Effective" for Osteoporosis (Natural Medicines).

Ipriflavone is rated Likely Effective for osteoporosis (bone loss) and Paget disease (a bone disorder). The evidence supports its use for these conditions, though you'd want to discuss with your doctor whether it's the right choice for your situation.

The evidence, ingredient by ingredient Ipriflavone

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.

Ipriflavone is generally well tolerated when taken by mouth, though some people report stomach pain, diarrhea, or dizziness. The bigger concern: long-term safety data is limited, and there's a risk of low white blood cell counts (lymphocytopenia) if you take it for at least 6 months or longer.

Because of possible estrogen-like effects and insufficient safety information, ipriflavone is not recommended during pregnancy or breastfeeding. If you're pregnant, planning to become pregnant, or breastfeeding, talk with your doctor or pharmacist before taking it.

Side effects, ingredient by ingredient Ipriflavone

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 — Ipriflavone.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: immunosuppressants / transplant drugs.
  • For scale: 391 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.

If you take theophylline, any blood thinners, muscle relaxants, antidepressants, or immunosuppressant drugs, you need to check with your doctor or pharmacist before adding ipriflavone. Given the scale of potential interactions (affecting over 300 medications), it's wise to review your entire medication list before starting.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Ipriflavone may be worth considering if you have osteoporosis or Paget disease and your doctor agrees—but it interacts with a large number of medications, especially theophylline, blood thinners, and immune-suppressing drugs. Before starting, run through your medication list with your doctor or pharmacist.

It's also not suitable during pregnancy or breastfeeding.

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 Aug 22, 2017.

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 Ipriflavone 300 mg, straight from the product label.

Brand NOW
Barcode (UPC) 733739014450
Net contents 90 Capsule(s)
Market status On market
Date entered into DSLD Aug 22, 2017
DSLD ID 77589
Product type Non-nutrient/non-botanical
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy 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 Ipriflavone 300 mg by NOW, 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:
2 Capsule(s)
Maximum serving Sizes:
2 Capsule(s)
Servings per container
45
UPC/BARCODE
733739014450
IngredientAmount% DV
Ipriflavone600 mg--

Other ingredients: Bovine Gelatin, Cellulose, Magnesium 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: Take 2 capsules daily, preferably with food.

General Statements

Ipriflavone is an isoflavone that has been scientifically shown to support a proper balance between the processes of bone formation and bone breakdown, which normally occurs in order to accommodate the calcium needs of the body. Clinical trials have demonstrated that Ipriflavone may help to sustain healthy bone metabolism.

Capsule size

Supports bone health Helps maintain healthy bone metabolism

General health Family owned since 1968.

Natural color variation may occur in this product.

FDA Disclaimer Statement

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

Precautions

Caution: For adults only.

Not for pregnant/nursing women. Consult your physician if you are taking any medications (especially those that suppress the immune system) or if you have a medical condition or immune disorders, or are planning to take this product long-term.

Not manufactured with yeast, wheat, gluten, soy, corn, milk, egg, fish, shellfish or tree nut ingredients. Produced in a GMP facility that processes other ingredients containing these allergens.

General

CODE 1445 V3

Seals/Symbols

Non-GMO

GMP Quality Assured

Formulation

Non-GMO

Not manufactured with yeast, wheat, gluten, soy, corn, milk, egg, fish, shellfish or tree nut ingredients.

FDA Statement of Identity

A Dietary Supplement

Storage

Store in a cool, dry place after opening.

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

See for yourself

Ipriflavone 300 mg by NOW label

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

Ipriflavone 300 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 Ipriflavone 300 mg by NOW

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.

Ipriflavone

Interacts with
391 drugs
600 mg per serving

Ipriflavone is a synthetic isoflavone studied mainly for bone health and osteoporosis, but high-quality research has not shown that it reliably preven...

Ipriflavone monograph & interactions

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

Interaction report

Ipriflavone 300 mg by NOW Drug Interactions

Want to check YOUR meds against Ipriflavone 300 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
391Drugs
391 Moderate

Ingredients driving the most interactions

Ipriflavone 391

Individual Drug Interactions

The ingredients in Ipriflavone 300 mg interact with 391 drugs. Click any drug to see the details.

1 of the 1 ingredient in Ipriflavone 300 mg interact with drugs. Each result below shows which ingredient is responsible. Ipriflavone

Each ingredient & the kinds of drugs it affects

For each ingredient in Ipriflavone 300 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.

Ipriflavone4 drug types · 391 drugs

Cytochrome P450 1A2 (Cyp1A2) Substrates

Ipriflavone is thought to competitively inhibit cytochrome P450 1A2 (CYP1A2). Theoretically, concurrent use of ipriflavone and drugs metabolized by these enzymes might result in decreased drug elimination, increased serum levels, and potential toxicity. Some drugs metabolized by CYP1A2 include clozapine (Clozaril), cyclobenzaprine (Flexeril), fluvoxamine (Luvox), haloperidol (Haldol), imipramine (Tofranil), mexiletine (Mexitil), olanzapine (Zyprexa), Pentazocine (Talwin), propranolol (Inderal), tacrine (Cognex), theophylline (Slo-bid, Theo-Dur, others), zileuton (Zyflo), Zolmitriptan (Zomig), and others.

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

Ipriflavone is thought to competitively inhibit cytochrome P450 2C9 (CYP2C9). Theoretically, concurrent use of ipriflavone and drugs metabolized by these enzymes might result in decreased drug elimination, increased serum levels, and potential toxicity. Some drugs metabolized by CYP2C9 include amitriptyline (Elavil), diazepam (Valium), estradiol (Estrace), tacrine (Cognex), verapamil (Calan), warfarin (Coumadin), zileuton (Zyflo), and others.

Likelihood Possible Evidence D
Immunosuppressants

Concurrent use of ipriflavone and immunosuppressant drugs might have additive effects on inhibiting immune function. Some patients taking ipriflavone experience subclinical lymphocytopenia; avoid concurrent use. Immunosuppressant drugs include azathioprine (Imuran), basiliximab (Simulect), cyclosporine (Neoral, Sandimmune), daclizumab (Zenapax), muromonab-CD3 (OKT3, Orthoclone OKT3), mycophenolate (CellCept), tacrolimus (FK506, Prograf), sirolimus (Rapamune), prednisone (Deltasone, Orasone), and other corticosteroids (glucocorticoids).

Likelihood Possible Evidence A
Theophylline

Concomitant use of theophylline and ipriflavone can increase serum theophylline levels. Increased theophylline levels have occurred in two cases after patients started taking ipriflavone. Ipriflavone is thought to decrease theophylline metabolism through competitive inhibition of the cytochrome P450 1A2 (CYP1A2) enzyme.

Likelihood Probable Evidence D
Ipriflavone full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Ipriflavone 300 mg, from the product label.

NOW

See all NOW products
Name
NOW FOODS
Street Address
395 S. Glen Ellyn Rd.
City
Bloomingdale
State
IL
ZipCode
60108
Web Address
www.nowfoods.com
Pharmacist Counseling Corner

Ipriflavone 300 mg by NOW: Common Questions

Does Ipriflavone 300 mg by NOW interact with any medications?
Yes. Based on its ingredients, Ipriflavone 300 mg has a known interaction with 391 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Ipriflavone 300 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.
Does ipriflavone actually work for bone loss?
Yes—it's rated Likely Effective for osteoporosis and Paget disease. That said, whether it's the best choice for you depends on your individual situation, other health conditions, and medications, so talk it through with your doctor.
What side effects should I watch for?
Most people tolerate it well, but some experience stomach pain, diarrhea, or dizziness. A more serious concern is the potential for low white blood cell counts if you take it long-term (6 months or longer), so your doctor may want to monitor you with blood tests.
Can I take this while pregnant or breastfeeding?
No—there isn't enough safety data, and ipriflavone may act like estrogen in your body. If you're pregnant, planning pregnancy, or breastfeeding, talk with your doctor or pharmacist before considering it.
What's in the capsule besides the active ingredient?
Bovine gelatin (the capsule shell), cellulose, and magnesium stearate. These are standard inactive ingredients that help form and stabilize the capsule.
Why do I need to check my medications before taking this?
Ipriflavone slows how your liver breaks down many common drugs, which can raise their levels in your blood. The most serious risk is with theophylline, but it can affect over 390 medications overall—so a quick review with your pharmacist is essential.

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

Not sure if Ipriflavone 300 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.

Ipriflavone 300 mg label
Go deeper

The Full Monographs Behind Ipriflavone 300 mg’s Ingredients

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

Herb & supplement monograph

Ipriflavone

Interacts with 391 drugs

Ipriflavone is a synthetic isoflavone studied mainly for bone health and osteoporosis, but high-quality research has not shown that it reliably prevents fractures or builds strong bone. Beca...

Read the full Ipriflavone monograph →
Sources

Sources & How We Checked

Ipriflavone 300 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 6 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.

Ipriflavone 6 references
  1. Agnusdei D, Bufalino L. Efficacy of ipriflavone in established osteoporosis and long-term safety. Calcif Tissue Int 1997;61,Suppl 1:S23-7. PubMed
  2. Alexandersen P, Toussaint A, Christiansen C, et al. Ipriflavone in the treatment of postmenopausal osteoporosis: A randomized controlled trial. JAMA 2001;285:1482-8.
  3. Agnusdei D, Camporeale A, Gonnelli S, et al. Short-term treatment of Paget's disease of bone with ipriflavone. Bone Miner 1992;19 Suppl 1:S35-42. PubMed
  4. Monostory K, Vereczkey L, Levai F, et al. Ipriflavone as an inhibitor of human cytochrome P450 enzymes. Br J Pharmacol 1998;123:605-10. PubMed
  5. Takahashi J, Kawakatsu K, Wakayama T, Sawaoka H. Elevation of serum theophylline levels by ipriflavone in a patient with chronic obstructive pulmonary disease. Eur J Clin Pharmacol 1992;43:207-8. PubMed
  6. Hu Q, Long C, Wu D, et al. The efficacy and safety of ipriflavone in postmenopausal women with osteopenia or osteoporosis: A systematic review and meta-analysis. Pharmacol Res. 2020;159:104860. PubMed

See these in context on the Ipriflavone 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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