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Dietary supplement

Full Spectrum Fennel Seed 480 mg Ingredients & Drug Interactions

by Swanson

Full Spectrum Fennel Seed 480 mg label
See full label image
Capsule 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 Full Spectrum Fennel Seed 480 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

Full Spectrum Fennel Seed 480 mg is a dietary supplement by Swanson 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. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Full Spectrum Fennel Seed 480 mg by Swanson

Ask about any prescription or over-the-counter medication and we check it for interactions with Full Spectrum Fennel Seed 480 mg by Swanson — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Full Spectrum Fennel Seed 480 mg by Swanson

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.

This product contains one active ingredient: fennel seed at 480 mg per capsule. Fennel is a culinary herb and seed traditionally used in herbal medicine.

The capsule itself is made of gelatin, with calcium palmitate and silica added as inactive ingredients to keep the powder from clumping.

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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: Traditional support for digestion and women's hormonal health.
  • We looked for evidence on: Dyspepsia, Flatulence, Dysmenorrhea, Menopausal symptoms, Lactation, Bloating — and 1 related terms.
  • The strongest evidence on file: Fennel is rated "Possibly Effective" for Dysmenorrhea (Natural Medicines).
  • Also on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Dyspepsia, Flatulence, Lactation, Menopausal symptoms.

Fennel has possibly effective evidence for dysmenorrhea (menstrual cramps). For anxiety, bronchitis, nocturnal enuresis (bedwetting), and cholera, the evidence we hold is insufficient to rate whether it works — the data just isn't solid enough 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 used as a food or in normal amounts. The most common side effects from oral use are gastrointestinal discomfort, sun sensitivity, and allergic reactions in people who are sensitive to it.

Rare serious side effects include seizures. Fennel seed is rated possibly unsafe in pregnancy and possibly unsafe while breastfeeding because the safety data is limited and fennel has hormone-like effects — concentrated supplements and the essential oil are the main concern, though medicinal doses haven't been well studied during nursing.

If you have a fennel or celery allergy (they're related botanically), watch for sneezing, coughing, itchy mouth, nasal congestion, or wheezing. There's also a rare link to asthma flares, and one case of severe reaction was reported with fennel-flavored toothpaste.

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 product, double-check with your doctor or pharmacist if you take blood thinners (anticoagulants or antiplatelets), birth control pills, hormone replacement therapy, tamoxifen, ciprofloxacin, or any medication broken down by your liver. Fennel may affect how these work or raise your bleeding risk.

Check your own medication Run your meds through the checker above

The bottom line

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

Fennel seed may help with menstrual cramps, but it's best avoided or used cautiously if you take blood thinners, birth control, hormone therapy, tamoxifen, ciprofloxacin, or certain other medications your liver processes. If you're pregnant or breastfeeding, talk with your doctor or pharmacist before taking a concentrated supplement — food amounts are likely fine, but medicinal doses haven't been studied enough.

Check your medications against the interaction tool before you start.

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 Feb 22, 2024.

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 Full Spectrum Fennel Seed 480 mg, straight from the product label.

Brand Swanson
Barcode (UPC) 087614019765
Net contents 100 Capsule(s)
Market status On market
Date entered into DSLD Feb 22, 2024
DSLD ID 308556
Product type Botanical
Supplement form Capsule
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 Full Spectrum Fennel Seed 480 mg by Swanson, sourced from the NIH Dietary Supplement Label Database.

Supplement Facts

Daily Value (DV) Target Group(s):
Adults and children 4 or more years of age
Minimum serving Sizes:
1 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
100
UPC/BARCODE
087614019765
IngredientAmount% DV
Fennel480 mg--

Other ingredients: Gelatin, Calcium Palmitate, Silica

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

Traditional support for proper digestion Helps support women's hormonal health Full Spectrum whole seed formula

Digestive support

Brand IP Statement(s)

Science-backed quality since 1969

Suggested/Recommended/Usage/Directions

Suggested use: As a dietary supplement, take one capsule three times per day with water.

Precautions

Warning: For adults only. Keep out of reach of children.

Consult your healthcare provider prior to using this or any product if you are pregnant or nursing, taking medication or have a medical condition.

Do not use if seal is broken.

Storage

Store in a cool, dry place.

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.

FDA Statement of Identity

Herbal Supplement

Formula

Full Spectrum Fennel Seed 480 mg per capsule

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

See for yourself

Full Spectrum Fennel Seed 480 mg by Swanson label

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

Full Spectrum Fennel Seed 480 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 Full Spectrum Fennel Seed 480 mg by Swanson

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

Serving size1 Capsule(s) Dosage formCapsule Servings per container100 Amounts shown are per serving.

Fennel

Interacts with
740 drugs
480 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 monograph & interactions

Other (inactive) ingredients: Gelatin, Calcium Palmitate, Silica. These complete the product’s ingredient list but are not active constituents.

Interaction report

Full Spectrum Fennel Seed 480 mg by Swanson Drug Interactions

Want to check YOUR meds against Full Spectrum Fennel Seed 480 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
740Drugs
740 Moderate

Ingredients driving the most interactions

Fennel 740

Individual Drug Interactions

The ingredients in Full Spectrum Fennel Seed 480 mg interact with 740 drugs. Click any drug to see the details.

1 of the 1 ingredient in Full Spectrum Fennel Seed 480 mg interact with drugs. Each result below shows which ingredient is responsible. Fennel

Each ingredient & the kinds of drugs it affects

For each ingredient in Full Spectrum Fennel Seed 480 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.

Fennel6 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 full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Full Spectrum Fennel Seed 480 mg, from the product label.

Swanson

See all Swanson products
Name
Swanson Health Products
City
Fargo
State
ND
ZipCode
58104
Phone Number
1-800-437-4148
Web Address
swanson.com
Pharmacist Counseling Corner

Full Spectrum Fennel Seed 480 mg by Swanson: Common Questions

Does Full Spectrum Fennel Seed 480 mg by Swanson interact with any medications?
Yes. Based on its ingredients, Full Spectrum Fennel Seed 480 mg 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?
Full Spectrum Fennel Seed 480 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.
Can I take fennel seed if I'm pregnant?
Fennel seed is rated possibly unsafe in pregnancy because the safety data is limited and fennel has hormone-like effects. Medicinal doses and concentrated supplements are the main concern. Talk with your doctor or pharmacist before taking it — they can help you decide whether it's right for you.
Does fennel seed help with bloating or digestion?
We don't have effectiveness data on file for fennel and bloating or general digestion. The facts we hold show fennel is possibly effective for menstrual cramps, but evidence for other digestive uses isn't in our current data.
What are the most common side effects?
Gastrointestinal discomfort, sensitivity to sunlight, and allergic reactions are the most common side effects reported with fennel. Most people tolerate it well. If you have a celery allergy, you may react to fennel too, since they're botanically related.
Is fennel seed safe while breastfeeding?
Fennel seed is rated possibly unsafe while breastfeeding because medicinal doses and the essential oil haven't been well studied in nursing. Food amounts are likely fine, but concentrated supplements need caution. Ask your doctor or pharmacist to help you decide what's safest for you and your baby.
Can I take fennel seed with my birth control?
Fennel may theoretically reduce how well birth control works because some of its compounds mimic estrogen. If you take oral contraceptives, check with your doctor or pharmacist before adding this supplement to make sure it won't interfere.
Does this product contain any fillers?
Yes — beyond the fennel seed, the capsule contains gelatin, calcium palmitate, and silica as inactive ingredients to preserve the powder.

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

Not sure if Full Spectrum Fennel Seed 480 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.

Full Spectrum Fennel Seed 480 mg label
Go deeper

The Full Monographs Behind Full Spectrum Fennel Seed 480 mg’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

Full Spectrum Fennel Seed 480 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 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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