Interactions on record — worth a quick check against your medications. Check your meds →
Dietary supplement

Catnip & Fennel Ingredients & Drug Interactions

by Nature's Sunshine

Catnip & Fennel label
See full label image
Liquid 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 Catnip & Fennel 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

Catnip & Fennel is a dietary supplement by Nature's Sunshine with 2 active ingredients. Its ingredients are commonly taken for sleep and insomnia, anxiety and stress, digestive upset.Based on those ingredients, 894 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Bitter Fennel seed Oil, Catnip leaf extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Catnip & Fennel by Nature's Sunshine

Ask about any prescription or over-the-counter medication and we check it for interactions with Catnip & Fennel by Nature's Sunshine — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
Prefer a human? Send your question to our licensed pharmacists — free, answered by email within 24 hours.

HelloPharmacist Scorecard of Catnip & Fennel by Nature's Sunshine

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 11, 2026

What’s inside

Low disclosure
Ingredient Transparency · database check
Low

Most active ingredients don't disclose an individual amount — you can't tell how much of each you're getting.

Why this rating?
  • The label discloses an exact amount for 0 of its 2 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label gives one combined amount (3.30 Gram(s)) without saying how much of each component you get.

This liquid formula contains 2 active ingredients: catnip leaf extract and bitter fennel seed oil, blended together in a proprietary formula. The extract and oil are suspended in vegetable glycerin and water as inactive ingredients.

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: traditional digestive support.
  • We looked for evidence on: Dyspepsia, Flatulence, Nausea and vomiting, Colic, Cough, Anxiety — and 4 related terms.
  • The closest evidence on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Anxiety (Natural Medicines).
  • Also on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Cough, Dyspepsia, Flatulence, Insomnia, and more.

The evidence for both ingredients is limited. Fennel has possibly effective evidence for dysmenorrhea (period pain), but catnip has insufficient reliable evidence to rate it for the conditions studied — including anxiety, tension headache, upper respiratory tract infection, and digestive complaints like upset stomach and gas.

If you're considering this product for a specific health goal, talk with us about whether the evidence supports it.

The evidence, ingredient by ingredient Catnip 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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 1 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.

Catnip is generally well tolerated in typical tea amounts, though human safety data are limited. The most common side effects are headache, malaise, and vomiting; large amounts may cause stomach upset.

Catnip must be avoided during pregnancy because it may stimulate the uterus and safety hasn't been established. Fennel is generally well tolerated as a food but requires more caution in medicinal or concentrated doses.

The most common side effects are gastrointestinal discomfort, sun sensitivity, and allergic reactions in sensitive people; seizures have been reported rarely. Fennel should be avoided in medicinal amounts during pregnancy due to limited safety data and hormone-like effects.

During breastfeeding, food amounts are likely fine, but medicinal doses and fennel essential oil are not well studied.

Side effects, ingredient by ingredient Catnip 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?
  • 2 of the 2 matched ingredients can interact with medications — Fennel, Catnip.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; lithium.
  • For scale: 895 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 if you use blood thinners or antiplatelet drugs (moderate risk of increased bleeding), CNS depressants like benzodiazepines or sleep aids (moderate risk of extra sedation), lithium (moderate risk of raised levels), oral contraceptives or hormone replacement therapy (moderate risk of reduced effectiveness), the antibiotic ciprofloxacin, tamoxifen for breast cancer, or any drugs metabolized by the liver enzyme CYP3A4.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFormula with limited ingredient disclosure with no established evidence rating for its marketed use. Moderate medication interactions have been identified, and safety information is well characterized.

This product may help with period pain, but the evidence for most other uses is weak or absent. If you take blood thinners, birth control, lithium, antibiotics, cancer drugs, or sedating medications, check your prescriptions with the tool on this page before starting.

Pregnant people should avoid it. Talk with your pharmacist if you're unsure whether it's right for you.

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 Oct 24, 2022.

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 Catnip & Fennel, straight from the product label.

Brand Nature's Sunshine
Barcode (UPC) 099904031951
Net contents 2 Fluid Ounce(s); 59 mL
Market status On market
Date entered into DSLD Oct 24, 2022
DSLD ID 278148
Product type Botanical
Supplement form Liquid
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 Catnip & Fennel by Nature's Sunshine, 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:
2.5 mL
Maximum serving Sizes:
5 mL
Servings per container
11
UPC/BARCODE
099904031951
IngredientAmount% DV
Proprietary Blend3.3 Gram(s)--
Catnip leaf extract0 NP--
Bitter Fennel seed Oil0 NP--

Other ingredients: Vegetable Glycerin, Water

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.
General Statements

Be a force of nature: Please recycle this bottle. We are committed to you and our planet. Scan to learn more.

We source the world's purest ingredients, no matter where they are grown, to ensure the active nutrients are delivered just as nature intended.

New look! Same great product

Precautions

Do not use if inner seal is missing or damaged.

FDA Disclaimer Statement

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

Formulation

Traditional digestive support Liquid herbal extracts

Guaranteed pure

FDA Statement of Identity

Dietary Supplement

Brand IP Statement(s)

Natures Sunshine Herbal experts since 1972

Suggested/Recommended/Usage/Directions

Recommended Use: Take 1/2 to 1 teaspoon (2.5 to 5 mL) in water with a meal three times daily. Shake well before using.

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

See for yourself

Catnip & Fennel by Nature's Sunshine label

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

Catnip & Fennel 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 Catnip & Fennel by Nature's Sunshine

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

Serving size2.5 mL Dosage formLiquid Servings per container11 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.

Proprietary Blend

3.3 Gram(s) per serving

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

Interaction report

Catnip & Fennel by Nature's Sunshine Drug Interactions

Want to check YOUR meds against Catnip & Fennel?

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
894Drugs
894 Moderate

Ingredients driving the most interactions

Bitter Fennel seed Oil 740
Catnip leaf extract 248

Individual Drug Interactions

The ingredients in Catnip & Fennel interact with 894 drugs. Click any drug to see the details.

2 of the 2 ingredients in Catnip & Fennel interact with drugs. Each result below shows which ingredient is responsible. Bitter Fennel seed Oil Catnip leaf extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Catnip & Fennel 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.

Bitter Fennel seed Oil6 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
Bitter Fennel seed Oil full monograph & interactions

Catnip leaf extract2 drug types · 248 drugs

Cns Depressants

Theoretically, concomitant use with drugs with sedative properties may cause additive effects and side effects.
Clinical and animal research shows that catnip has sedative properties.

Likelihood Possible Evidence D
Lithium

Theoretically, catnip might reduce excretion and increase levels of lithium.
Catnip is thought to have diuretic properties which might reduce lithium excretion. The dose of lithium might need to be decreased.

Likelihood Probable Evidence D
Catnip leaf extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Catnip & Fennel, from the product label.

Nature's Sunshine

See all Nature's Sunshine products
Name
Nature's Sunshine Products, Inc.
City
Spanish Fork
State
UT
ZipCode
84660
Phone Number
1-800-223-8225
Web Address
www.naturessunshine.com
Pharmacist Counseling Corner

Catnip & Fennel by Nature's Sunshine: Common Questions

Does Catnip & Fennel by Nature's Sunshine interact with any medications?
Yes. Based on its ingredients, Catnip & Fennel has a known interaction with 894 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Catnip & Fennel 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 while pregnant?
No. Catnip may stimulate the uterus and safety during pregnancy isn't established; fennel in medicinal amounts should also be avoided during pregnancy due to limited safety data and possible hormone-like effects. Talk with your doctor or midwife before using any herbal supplement while pregnant.
Is it safe to breastfeed while taking this?
There isn't enough data to know either way. Food amounts of fennel are likely fine, but this is a medicinal product with concentrated fennel oil, and safety while breastfeeding hasn't been well studied. Ask your pharmacist or doctor for personalized advice.
What are the side effects?
Catnip commonly causes headache, malaise, and vomiting; large amounts may cause stomach upset. Fennel most often causes gastrointestinal discomfort, sun sensitivity, and allergic reactions in sensitive people. Seizures from fennel are rare but have been reported.
Does catnip actually work for anxiety?
The evidence isn't strong enough to say. Catnip has insufficient reliable evidence for anxiety, tension headache, and most other conditions it's used for. Fennel does have some evidence for period pain, so that's the clearest use in this formula.
Why is there a warning about sun sensitivity with this product?
Fennel can cause photosensitivity in some people, meaning your skin may react more easily to sunlight. If you use this product regularly, be extra careful with sun exposure and wear sunscreen.

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

Not sure if Catnip & Fennel is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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.

Catnip & Fennel label
Go deeper

The Full Monographs Behind Catnip & Fennel’s Ingredients

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

Herb & supplement monograph

Catnip

Interacts with 248 drugs

Catnip is a mint-family herb most often used as a calming tea for sleep, anxiety, and minor digestive upset, but solid human research supporting these uses is lacking. It is generally consid...

Read the full Catnip monograph → 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

Catnip & Fennel'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 24 references behind this product’s interaction data

Every citation that drives the interaction findings for this product’s ingredients, from the evidence-graded Natural Medicines (TRC Healthcare) database. Open an ingredient to browse its citations — links open the study on PubMed or the publisher’s site.

Catnip 7 references
  1. Foster S, Tyler VE. Tyler's Honest Herbal: A Sensible Guide to the Use of Herbs and Related Remedies. 3rd ed., Binghamton, NY: Haworth Herbal Press, 1993.
  2. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  3. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  4. Osterhoudt KC, Lee SK, Callahan JM, Henretig FM. Catnip and the alteration of human consciousness. Vet Hum Toxicol 1997;39:373-5.
  5. Sherry, C. J. and Hunter, P. S. The effect of an ethanol extract of catnip (Nepeta cataria) on the behavior of the young chick. Experientia 2-15-1979;35(2):237-238. PubMed
  6. Harney, J. W., Barofsky, I. M., and Leary, J. D. Behavioral and toxicological studies of cyclopentanoid monoterpenes from Nepeta cataria. Lloydia. 1978;41(4):367-374.
  7. Massoco, C. O., Silva, M. R., Gorniak, S. L., Spinosa, M. S., and Bernardi, M. M. Behavioral effects of acute and long-term administration of catnip (Nepeta cataria) in mice. Vet.Hum.Toxicol 1995;37(6):530-533.

See these in context on the Catnip monograph →

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

Keep exploring
Supplement interaction checker › Check any supplement or product against your medications Drug–drug interactions › Check two or more of your medications against each other Browse medications A–Z › Every drug we've checked against herbs & supplements NDC & pricing lookup › Find a drug’s NDCs, packaging and costs Ask a pharmacist › Free, personal answer from our licensed team