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Dietary supplement

Fennel 4:1 Extract Powder Ingredients & Drug Interactions

by TerraVita Premium Collection

Fennel 4:1 Extract Powder label
See full label image
Powder Category: 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 Fennel 4:1 Extract Powder 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

Fennel 4:1 Extract Powder is a dietary supplement by TerraVita Premium Collection with 1 active ingredient. Its ingredients are commonly taken for digestive upset and bloating, infant colic, menstrual cramps.Based on those ingredients, 740 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Fennel Extract, Powder. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Fennel 4:1 Extract Powder by TerraVita Premium Collection

Ask about any prescription or over-the-counter medication and we check it for interactions with Fennel 4:1 Extract Powder by TerraVita Premium Collection — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Fennel 4:1 Extract Powder by TerraVita Premium Collection

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

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 30, 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.

TerraVita Premium Collection Fennel 4:1 Extract Powder contains one active ingredient: fennel extract in a 4:1 concentration, meaning the powder is made from four parts raw fennel material reduced to one part extract. This is a powdered form designed to deliver fennel's active compounds in a concentrated dose.

There are no inactive ingredients listed for this product.

Does it work?

Moderate 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

This product doesn't appear to be marketed for a specific use, so we graded Fennel's overall clinical evidence instead.

Moderate

Some clinical evidence supports Fennel for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Dysmenorrhea — rated "Possibly Effective" (Natural Medicines).

The evidence for fennel is mixed. It's rated as possibly effective for dysmenorrhea — painful menstrual cramps — based on available studies.

For other uses listed in the data we hold — bronchitis, anxiety, nocturnal enuresis (bedwetting), and cholera — the evidence is insufficient to establish whether fennel works, meaning either too few studies exist, the studies are weak, or results are inconsistent. If you're considering this for dysmenorrhea, there's a reasonable basis; for other conditions, the science isn't settled yet.

The evidence, ingredient by ingredient Fennel

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.

Fennel is generally well tolerated when eaten as food, but concentrated supplements like this extract powder warrant more caution. The most common side effects from oral fennel are gastrointestinal discomfort (digestive upset), photosensitivity (increased sun sensitivity of the skin), and allergic reactions in people prone to them — though severe allergies are rare.

One case report describes a child who had a respiratory reaction (sneezing, coughing, wheezing, and difficulty breathing) to fennel in toothpaste, though it resolved quickly. Very rarely, seizures have been reported with oral fennel.

During pregnancy, medicinal or concentrated amounts of fennel are rated as possibly unsafe due to limited safety data and fennel's hormone-like effects; food amounts are likely fine. While breastfeeding, the essential oil and medicinal doses haven't been well studied — food amounts are probably okay, but talk with your doctor or pharmacist about whether a concentrated supplement is right for you.

Side effects, ingredient by ingredient Fennel

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 — Fennel.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 741 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 fennel extract, double-check with your doctor or pharmacist if you take any of these medication types: contraceptive drugs, hormone replacement therapy (estrogens), tamoxifen, blood thinners (anticoagulants or antiplatelet drugs like warfarin or aspirin), drugs metabolized by the liver enzyme CYP3A4 (a very large category that includes many common medications), or the antibiotic ciprofloxacin (Cipro). All of these carry documented Moderate interaction risks with fennel.

The interaction checker on this page can help you look up your specific medications.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with some supporting evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This product may be worth considering if you're interested in fennel for dysmenorrhea, where some evidence exists. However, the Moderate interaction risk with 741 medications — especially contraceptives, hormone therapy, tamoxifen, blood thinners, and ciprofloxacin — makes it essential to check your exact medications before you start.

If you're pregnant or breastfeeding and considering a medicinal dose, talk with your doctor or pharmacist first, since safety data is limited. Run any questions about whether this fits your situation past your own healthcare provider.

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 Jun 22, 2023.

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 Fennel 4:1 Extract Powder, straight from the product label.

Brand TerraVita Premium Collection
Barcode (UPC) 064435200787
Net contents 1 Ounce(s)
Market status On market
Date entered into DSLD Jun 22, 2023
DSLD ID 290683
Product type Botanical
Supplement form Powder
Dietary claims / uses All Other, Structure/Function
Intended target group(s) 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 Fennel 4:1 Extract Powder by TerraVita Premium Collection, 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:
0.25 Teaspoon(s)
Maximum serving Sizes:
0.25 Teaspoon(s)
Servings per container
28
UPC/BARCODE
064435200787
IngredientAmount% DV
Fennel Extract, Powder1000 mg--

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.
FDA Statement of Identity

A Dietary Supplement

Brand IP Statement(s)

Copyright 2017 TerraVita - Distributed by ZooScape LLC, All Rights Reserved.

Suggested/Recommended/Usage/Directions

Directions Stir 1/4 of a teaspoon into a glass of water and consume 3 times daily, with meals.

General Statements

TerraVita is an exclusive line of premium natural products that use the finest, purest and most potent ingredients in the world. TerraVita's hallmarks are the highest possible standards of purity, potency, stability and freshness. All products are prepared with the greatest quality control, from raw materials through the entire manufacturing process, right up to the moment your product is sealed for freshness and shipped to you.

Please recycle!

FDA Disclaimer Statement

Statements not evaluated by FDA. Product not intended to diagnose, treat, cure, or prevent any disease.

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

See for yourself

Fennel 4:1 Extract Powder by TerraVita Premium Collection label

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

Fennel 4:1 Extract Powder 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 Fennel 4:1 Extract Powder by TerraVita Premium Collection

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

Serving size0.25 Teaspoon(s) Dosage formPowder Servings per container28 Amounts shown are per serving.

Fennel Extract, Powder

Interacts with
740 drugs
1000 mg per serving

Fennel is a Mediterranean herb widely used as a food and spice, and traditionally taken for digestive complaints, colic, and menstrual cramps. Some sm...

Fennel Extract, Powder monograph & interactions
Interaction report

Fennel 4:1 Extract Powder by TerraVita Premium Collection Drug Interactions

Want to check YOUR meds against Fennel 4:1 Extract Powder?

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
740Drugs
740 Moderate

Ingredients driving the most interactions

Fennel Extract, Powder 740

Individual Drug Interactions

The ingredients in Fennel 4:1 Extract Powder interact with 740 drugs. Click any drug to see the details.

1 of the 1 ingredient in Fennel 4:1 Extract Powder interact with drugs. Each result below shows which ingredient is responsible. Fennel Extract, Powder

Each ingredient & the kinds of drugs it affects

For each ingredient in Fennel 4:1 Extract Powder 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.

Fennel Extract, Powder6 drug types · 740 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, fennel might increase the risk of bleeding when used with antiplatelet or anticoagulant drugs.

Animal research suggests that fennel oil has antithrombotic and antiplatelet effects.

Likelihood Possible Evidence D
Ciprofloxacin (Cipro)

Theoretically, fennel might decrease the levels and clinical effects of ciprofloxacin.

Animal research shows that fennel reduces ciprofloxacin bioavailability by nearly 50%, possibly due to the metal cations such as calcium, iron, and magnesium contained in fennel. This study also found that fennel increased tissue distribution and slowed elimination of ciprofloxacin.

Likelihood Probable Evidence D
Contraceptive Drugs

Theoretically, taking large amounts of fennel might decrease the effects of contraceptive drugs due to competition for estrogen receptors.

Some constituents of fennel have estrogenic activity.

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

Theoretically, fennel might increase levels of drugs metabolized by CYP3A4.

In vitro research suggests that fennel inhibits CYP3A4 enzyme activity. This effect has not been reported in humans.

Likelihood Possible Evidence D
Estrogens

Theoretically, taking large amounts of fennel might interfere with hormone replacement therapy due to competition for estrogen receptors.

Some constituents of fennel have estrogenic activity.

Likelihood Possible Evidence D
Tamoxifen (Nolvadex)

Theoretically, taking large amounts of fennel might decrease the antiestrogenic effect of tamoxifen.

Some constituents of fennel have estrogenic activity, which may interfere with the antiestrogenic activity of tamoxifen.

Likelihood Possible Evidence D
Fennel Extract, Powder full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Fennel 4:1 Extract Powder, from the product label.

TerraVita Premium Collection

See all TerraVita Premium Collection products
Name
TerraVita Fine Whole Herbs
City
Brampton
State
Ontario
Pharmacist Counseling Corner

Fennel 4:1 Extract Powder by TerraVita Premium Collection: Common Questions

Does Fennel 4:1 Extract Powder by TerraVita Premium Collection interact with any medications?
Yes. Based on its ingredients, Fennel 4:1 Extract Powder has a known interaction with 740 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Fennel 4:1 Extract Powder 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 if I'm on birth control?
Not safely without checking first. Fennel's estrogenic compounds may theoretically decrease how well contraceptive drugs work by competing for estrogen receptors — a Moderate-severity concern. Talk with your doctor or pharmacist about your specific birth control before starting this supplement.
Does fennel extract actually help with period cramps?
Possibly — fennel is rated as possibly effective for dysmenorrhea (painful menstrual cramps), which means some studies support it, though the evidence isn't as strong as for some other remedies. Results vary, so it may work for you and it may not.
What are the side effects?
Most common are stomach upset, increased sun sensitivity, and allergic reactions (rare). Serious side effects like seizures have been reported but are very rare with fennel. A small number of people have had respiratory reactions to fennel-containing products, though severe reactions are uncommon.
Is this safe during pregnancy?
Medicinal or concentrated doses are rated as possibly unsafe during pregnancy due to limited safety data and fennel's hormone-like effects. Eating fennel as food is likely fine, but a concentrated supplement powder falls into the medicinal category — talk with your doctor or pharmacist about whether it's right for you.
Can I use this while breastfeeding?
Food amounts of fennel are probably fine, but medicinal doses and the essential oil haven't been well studied in nursing mothers. Since this is a concentrated extract, talk with your doctor or pharmacist about whether it's safe for you to use while breastfeeding.
Does it interact with antibiotics?
Yes — specifically ciprofloxacin (Cipro). Animal research shows fennel reduces how much of this antibiotic your body absorbs by about half, likely because fennel contains minerals that bind to the drug. If you take Cipro, check with your doctor or pharmacist before using this supplement.

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.

Fennel 4:1 Extract Powder label
Go deeper

The Full Monographs Behind Fennel 4:1 Extract Powder’s Ingredients

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

Herb & supplement monograph

Fennel

Interacts with 740 drugs

Fennel is a Mediterranean herb widely used as a food and spice, and traditionally taken for digestive complaints, colic, and menstrual cramps. Some small studies suggest possible benefit for...

Read the full Fennel monograph →
Sources

Sources & How We Checked

Fennel 4:1 Extract Powder'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 17 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.

Fennel 17 references
  1. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  3. Zhu M, Wong PY, Li RC. Effect of oral administration of fennel (Foeniculum vulgare) on ciprofloxacin absorption and disposition in the rat. J Pharm Pharmacol 1999;51:1391-6.
  4. Gral N, Beani JC, Bonnot D, et al. [Plasma levels of psoralens after celery ingestion]. Ann Dermatol Venereol 1993;120:599-603.
  5. Burkhard PR, Burkhardt K, Haenggeli CA, Landis T. Plant-induced seizures: reappearance of an old problem. J Neurol 1999;246:667-70. PubMed
  6. Rosti L, Nardini A, Bettinelli ME, Rosti D. Toxic effects of a herbal tea mixture in two newborns. Acta Paediatrica 1994;83:683. PubMed
  7. Cuzzolin L, Zaffani S, and Benoni G. Safety implications regarding use of phytomedicines. Eur.J Clin Pharmacol. 2006;62:37-42. PubMed
  8. Tognolini, M., Ballabeni, V., Bertoni, S., Bruni, R., Impicciatore, M., and Barocelli, E. Protective effect of Foeniculum vulgare essential oil and anethole in an experimental model of thrombosis. Pharmacol.Res 2007;56(3):254-260. PubMed
  9. Subehan, Usia, T., Iwata, H., Kadota, S., and Tezuka, Y. Mechanism-based inhibition of CYP3A4 and CYP2D6 by Indonesian medicinal plants. J Ethnopharmacol. 5-24-2006;105(3):449-455. PubMed
  10. Tognolini, M., Barocelli, E., Ballabeni, V., Bruni, R., Bianchi, A., Chiavarini, M., and Impicciatore, M. Comparative screening of plant essential oils: phenylpropanoid moiety as basic core for antiplatelet activity. Life Sci. 2-23-2006;78(13):1419-1432. PubMed
  11. Subehan, Zaidi, S. F., Kadota, S., and Tezuka, Y. Inhibition on human liver cytochrome P450 3A4 by constituents of fennel (Foeniculum vulgare): identification and characterization of a mechanism-based inactivator. J Agric.Food Chem. 12-12-2007;55(25):101 PubMed
  12. LEVY, S. B. Bronchial asthma due to ingestion of fennel and fennel seed. Ann.Allergy 1948;6(4):415.
  13. Ottolenghi, A., De Chiara, A., Arrigoni, S., Terracciano, L., and De Amici, M. [Diagnosis of food allergy caused by fruit and vegetables in children with atopic dermatitis]. Pediatr Med Chir 1995;17(6):525-530.
  14. Trabace L, Tucci P, Ciuffreda L, et al. "Natural" relief of pregnancy-related symptoms and neonatal outcomes: above all do no harm. J Ethnopharmacol. 2015;174:396-402. PubMed
  15. Denaxa D, Arkwright PD. Fennel as a cause of immediate hypersensitivity to toothpaste. Ann Allergy Asthma Immunol. 2020;125(1):99-100. PubMed
  16. Lee HW, Ang L, Lee MS, Alimoradi Z, Kim E. Fennel for reducing pain in primary dysmenorrhea: a systematic review and meta-analysis of randomized controlled trials. Nutrients 2020;12(11):3438. PubMed
  17. Mathew T, John SK, Javali M, Vasireddy M, Nadig R, Sarma GRK. Substance use related cluster headache: A case series. Headache 2022;62(7):908-910. PubMed

See these in context on the Fennel 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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