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

Stomach Tonic Ingredients & Drug Interactions

by Herbs Etc.

Stomach Tonic label
See full label image
Liquid Category: Botanical
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 9, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Stomach Tonic 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

Stomach Tonic is a dietary supplement by Herbs Etc. with 9 active ingredients. Its ingredients are commonly taken for loss of appetite, indigestion and bloating, digestive bitter tonic.Based on those ingredients, 1,148 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Chamomile flower extract, Fennel seed extract, Catnip Flower Top Extract, Fresh. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Stomach Tonic by Herbs Etc.

Ask about any prescription or over-the-counter medication and we check it for interactions with Stomach Tonic by Herbs Etc. — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Stomach Tonic by Herbs Etc.

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 9 active ingredients.
  • “Proprietary Extract Blend” is a proprietary blend — the label gives one combined amount (0.75 mL) without saying how much of each component you get.

Stomach Tonic contains 9 ingredients, including gentian root extract and fennel seed extract as active herbal components, along with angelica root, chamomile flower, prickly ash bark, cardamom pod, catnip flower top, lavender flower, and star anise fruit — all provided as extracts. The product is formulated as a liquid with alcohol, purified water, and glycerine 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: Promotes gas and acid relief.
  • We looked for evidence on: Colic, Constipation, Dyspepsia, Flatulence, Gastritis, Gastroesophageal reflux disease (GERD) — and 4 related terms.
  • The closest evidence on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Constipation (Natural Medicines).
  • Also on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Dyspepsia, Flatulence, Irritable bowel syndrome (IBS), Nausea and vomiting, and more.
  • Also on file: Cardamom is rated "Insufficient Reliable Evidence To Rate" for Dyspepsia.

The evidence supporting this product's ingredients is limited. Fennel seed is possibly effective for painful periods (dysmenorrhea), and lavender flower is possibly effective for dysmenorrhea as well.

For the other conditions the ingredients are used for — gentian for wound healing, obesity, or sinus inflammation; chamomile for anxiety or digestion; catnip for headaches or respiratory infections; and cardamom for blood sugar or cholesterol — the data we hold show insufficient reliable evidence to rate them. Star anise has no effectiveness ratings in our data.

The evidence, ingredient by ingredient Gentian Fennel Ashitaba German Chamomile Northern Prickly Ash Cardamom Catnip Lavender

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 7 of the 9 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 8 of 9.
  • General safety write-ups exist for 9 of 9.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Gentian root is generally tolerated in small amounts but can upset the stomach and shouldn't be used at high doses — avoid it during pregnancy and while breastfeeding. Fennel seed is generally safe as a food but in concentrated supplement form carries cautions; avoid medicinal amounts in pregnancy due to its hormone-like effects, and use only food amounts while breastfeeding.

Catnip is likely fine in tea amounts but may stimulate the uterus, so avoid it in pregnancy; breastfeeding safety isn't established, so skip it. Lavender is well tolerated in approved forms, though the essential oil is toxic if swallowed and can irritate skin; avoid medicinal amounts in pregnancy and use only under medical guidance while breastfeeding.

Cardamom and star anise in food amounts are generally well tolerated, though star anise tea has rarely been linked to serious neurological effects — stick to food amounts. Common side effects across these ingredients include gastrointestinal upset, headache, nausea, and in rare cases allergic reactions.

Side effects, ingredient by ingredient Gentian Fennel Ashitaba German Chamomile Northern Prickly Ash Cardamom Catnip Lavender

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?
  • 7 of the 9 matched ingredients can interact with medications — Northern Prickly Ash, Fennel, Gentian, Catnip, Lavender, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; lithium.
  • For scale: 1,149 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.

Check with your pharmacist before using this product if you take blood pressure medications (antihypertensives), birth control pills (contraceptives), hormone replacement therapy (estrogens), blood thinners or antiplatelet drugs, the antibiotic ciprofloxacin (Cipro), the cancer drug tamoxifen (Nolvadex), lithium, or any sedative medications (CNS depressants). Fennel seed and gentian root are the primary sources of these interactions.

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.

If you take blood pressure medications, birth control, blood thinners, lithium, sleep aids, or ciprofloxacin (Cipro), check with your pharmacist before using this product. Pregnant women and those breastfeeding should talk to their doctor or pharmacist first, as several ingredients carry cautions.

For most healthy adults using normal amounts, gastrointestinal upset is the most common concern. Run your exact medications through the tool on this page.

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

Assessment coverage: 9 of 9 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Nov 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 Stomach Tonic, straight from the product label.

Brand Herbs Etc.
Barcode (UPC) 765704106013
Net contents 1 Fluid Ounce(s); 30 mL
Market status On market
Date entered into DSLD Nov 22, 2024
DSLD ID 320887
Product type Botanical
Supplement form Liquid
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Children 4 or More Years of Age, Vegan, Vegetarian, Adult (18 - 50 Years), Women (not pregnant or lactating), Infants/Baby (0 - 1 Year)
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 Stomach Tonic by Herbs Etc., 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:
30 Drop(s), 4 Drop(s)
Maximum serving Sizes:
30 Drop(s), 4 Drop(s)
Servings per container
40
UPC/BARCODE
765704106013
IngredientAmount% DV
Gentian root extract0 NP--
Proprietary Extract Blend0.75 mL--
Fennel seed extract0 NP--
Angelica root extract0 NP--
Chamomile flower extract0 NP--
Prickly Ash Bark Extract0 NP--
Cardamom Pod Extract0 NP--
Catnip Flower Top Extract, Fresh0 NP--
Lavender Flower Extract, Fresh0 NP--
Star Anise Fruit Extract0 NP--

Other ingredients: Alcohol, Water, Purified, Glycerine

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

Promotes gas and acid relief

Gluten free No artificial preservatives.

Vegan

Manufactured in Santa Fe, NM.

FDA Statement of Identity

Herbal Supplement

Formula

Stomach Tonic is made with gas and acid relieving herbs, including chamomile, catnip and fennel.

Note: Safe for babies two months and older.

General Statements

We apply our company philosophy to Stomach Tonic, as we do to all of our herbal medicines. That philosophy is to do what's right, which extends to choosing the right herbs, using the right processes, and making the right formulations that support your health needs. We do all of this to bring you herbal medicines made right.

Herbal formula

Suggested/Recommended/Usage/Directions

Suggested use: For adults, take 30 drops in water three times a day, after meals or before bedtime. For babies, give four drops diluted in a liquid, up to three times a day, after meals or before bedtime.

Precautions

Caution: Do not use during pregnancy.

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.

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

See for yourself

Stomach Tonic by Herbs Etc. label

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

Stomach Tonic 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 Stomach Tonic by Herbs Etc.

These are the 9 active ingredients this product is made of. Select any to open its full monograph.

Serving size30 Drop(s) Dosage formLiquid Servings per container40 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.

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

Interaction report

Stomach Tonic by Herbs Etc. Drug Interactions

Want to check YOUR meds against Stomach Tonic?

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
1,148Drugs
1,133 Moderate 15 Minor

Ingredients driving the most interactions

Chamomile flower extract 960
Fennel seed extract 740
Catnip Flower Top Extract, Fresh 248
Lavender Flower Extract, Fresh 248
Angelica root extract 186

Individual Drug Interactions

The ingredients in Stomach Tonic interact with 1,148 drugs. Click any drug to see the details.

7 of the 9 ingredients in Stomach Tonic interact with drugs. Each result below shows which ingredient is responsible. Chamomile flower extract Fennel seed extract Catnip Flower Top Extract, Fresh Lavender Flower Extract, Fresh Angelica root extract Gentian root extract Prickly Ash Bark Extract

Each ingredient & the kinds of drugs it affects

For each ingredient in Stomach Tonic 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.

Chamomile flower extract9 drug types · 960 drugs

Cns Depressants

Theoretically, German chamomile might have additive effects when used with CNS depressants.
German chamomile has mild sedative effects. Theoretically, concomitant use with drugs with sedative properties can cause additive effects and side effects.

Likelihood Possible Evidence D
Contraceptive Drugs

Theoretically, large amounts of German chamomile might reduce the effectiveness of oral contraceptives.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, concomitant use of large amounts of German chamomile might interfere with contraceptive drugs through competition for estrogen receptors.

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

Theoretically, German chamomile might inhibit CYP2C9 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP2C9. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP2C9 in patients taking German chamomile.

Likelihood Possible Evidence D
Cytochrome P450 2D6 (Cyp2D6) Substrates

Theoretically, German chamomile might inhibit CYP2D6 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP2D6. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP2D6 in patients taking German chamomile.

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

Theoretically, German chamomile might inhibit CYP3A4 and increase levels of drugs metabolized by these enzymes.
In vitro evidence shows that German chamomile might inhibit CYP3A4. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP3A4 in patients taking German chamomile.

Likelihood Possible Evidence D
Estrogens

Theoretically, large amounts of German chamomile might reduce the effectiveness of estrogens.
In vitro, German chamomile has demonstrated antiestrogenic activity. Theoretically, large amounts of German chamomile might interfere with hormone replacement therapy through competition for estrogen receptors.

Likelihood Possible Evidence D
Tamoxifen (Nolvadex)

Theoretically, large amounts of German chamomile might interfere with the activity of tamoxifen.
In vitro, German chamomile has demonstrated antiestrogenic activity.

Likelihood Possible Evidence D
Warfarin (Coumadin)

German chamomile might increase the effects of warfarin and increase the risk of bleeding.
In one case, a 70-year-old female taking warfarin developed retroperitoneal hematoma and bilateral recti muscle bleeding along with an INR of 7.9 following ingestion of German chamomile tea 4-5 cups daily and use of a topical chamomile-based lotion applied 4-5 times daily.

Likelihood Possible Evidence D
Cytochrome P450 1A2 (Cyp1A2) Substrates

Theoretically, German chamomile might inhibit CYP1A2 and increase levels of drugs metabolized by these enzymes.
In vitro and animal research shows that German chamomile might inhibit CYP1A2. So far, this interaction has not been reported in humans. However, there might be an increase in the levels of drugs metabolized by CYP1A2 in patients taking German chamomile.

Likelihood Possible Evidence D
Chamomile flower extract full monograph & interactions

Fennel seed extract6 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 seed extract full monograph & interactions

Catnip Flower Top Extract, Fresh2 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 Flower Top Extract, Fresh full monograph & interactions

Lavender Flower Extract, Fresh1 drug type · 248 drugs

Cns Depressants

Theoretically, lavender might potentiate the therapeutic effects and adverse effects of CNS depressants.
Laboratory research suggests that lavender has sedative effects. However, clinical studies in patients taking oral lavender oil (Silexan) 160 mg for 10 weeks or taking lavender flower powder 1 gram daily for 2 months have not reported side effects of drowsiness, sedation, or sleepiness. There is still some concern that higher doses or different preparations of lavender might have additive effects with CNS depressant medications.

Likelihood Unlikely Evidence D
Lavender Flower Extract, Fresh full monograph & interactions

Angelica root extract1 drug type · 186 drugs

Cytochrome P450 1A2 (Cyp1A2) Substrates

In vitro research shows that ashitaba extract inhibits cytochrome P450 (CYP) 1A2. Theoretically, concomitant use of ashitaba with CYP1A2 substrates might decrease the clearance of these substrates and increase the risk for adverse effects. However, this interaction has yet to be reported in humans. Until more is known, use with caution.

Likelihood Possible Evidence D
Angelica root extract full monograph & interactions

Gentian root extract1 drug type · 172 drugs

Antihypertensive Drugs

Theoretically, taking gentian with antihypertensive drugs might increase the risk of hypotension.
In vitro research shows that gentian can cause vasodilation and lower blood pressure.

Likelihood Possible Evidence D
Gentian root extract full monograph & interactions

Prickly Ash Bark Extract3 drug types · 36 drugs

Antacids

Theoretically, northern prickly ash might decrease the effectiveness of antacids.
There are reports that northern prickly ash increases stomach acid.

Likelihood Possible Evidence D
H2-Blockers

Theoretically, northern prickly ash might decrease the effectiveness of H2-blockers.
There are reports that northern prickly ash increases stomach acid.

Likelihood Possible Evidence D
Proton Pump Inhibitors (Ppis)

Theoretically, northern prickly ash might decrease the effectiveness of PPIs.
There are reports that northern prickly ash increases stomach acid.

Likelihood Possible Evidence D
Prickly Ash Bark Extract full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Stomach Tonic, from the product label.

Herbs Etc.

Name
Herbs, Etc., Inc.
Street Address
1340 Rufina Circle
City
Santa Fe
State
NM
ZipCode
87507
Web Address
www.herbsetc.com
Pharmacist Counseling Corner

Stomach Tonic by Herbs Etc.: Common Questions

Does Stomach Tonic by Herbs Etc. interact with any medications?
Yes. Based on its ingredients, Stomach Tonic has a known interaction with 1,148 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Stomach Tonic contains 9 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?
Several ingredients — gentian, fennel, and catnip — advise against use in pregnancy. Lavender isn't well studied in pregnancy either. The safety data recommend talking with your doctor or pharmacist before taking this product if you're pregnant, as personalized advice depends on your health history.
Is this safe to use while breastfeeding?
Gentian and catnip should be avoided while breastfeeding due to insufficient safety data. Fennel food amounts are likely fine, but medicinal doses aren't well studied. Lavender safety isn't established either. Chat with your pharmacist or doctor for guidance on whether this product fits your situation.
What does fennel seed do in this formula?
Fennel seed is included for digestive support — it's possibly effective for painful periods and is traditionally used for stomach complaints. It's generally safe as a food but in supplement form carries cautions, especially with certain medications and in pregnancy.
Why is there alcohol in a stomach tonic?
The product is formulated as a liquid extract using alcohol and water as preservatives and to extract the active plant compounds. If you need to avoid alcohol entirely, check with your pharmacist about alternative formulations or dosing options.
Will this make me drowsy?
Catnip and lavender have sedative properties, so you may feel more relaxed or sleepy, especially in larger amounts. This effect will worsen if you're also taking sleep aids, anxiety medications, or pain relievers — another reason to check with your pharmacist first.
What are the most common side effects?
Gastrointestinal upset — including nausea, diarrhea, and bloating — is the most commonly reported side effect from these ingredients. Headache, constipation, and allergic reactions in sensitive individuals have also been reported. If you experience severe or persistent symptoms, stop use and talk to your pharmacist.

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.

Stomach Tonic label
Go deeper

The Full Monographs Behind Stomach Tonic’s Ingredients

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

Herb & supplement monograph

Gentian

Interacts with 172 drugs

Gentian is a very bitter root traditionally used to stimulate appetite and ease mild digestive complaints, often as part of "bitters" before meals. The evidence is mostly traditional and pre...

Read the full Gentian 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 → Herb & supplement monograph

Ashitaba

Interacts with 186 drugs

Ashitaba is a leafy plant from Japan that is eaten as a vegetable and taken as a supplement for general health, antioxidant, and heart benefits. Most of the supporting research comes from la...

Read the full Ashitaba monograph → Herb & supplement monograph

German Chamomile

Interacts with 960 drugs

German chamomile is a widely used herbal remedy taken mainly as a tea for calming, sleep, and digestive complaints. Early research suggests possible benefits for mild anxiety and some skin o...

Read the full German Chamomile monograph → Herb & supplement monograph

Northern Prickly Ash

Interacts with 36 drugs

Northern Prickly Ash is a North American shrub whose bark and berries have a long history in folk medicine, especially for toothache, joint pain, and sluggish digestion. Modern scientific ev...

Read the full Northern Prickly Ash monograph → Herb & supplement monograph

Cardamom

Cardamom is a popular cooking spice that has long been used in traditional medicine for digestion and fresh breath. As a food, it is generally safe for most people, but high-dose supplements...

Read the full Cardamom monograph → 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

Lavender

Interacts with 248 drugs

Lavender is a fragrant herb most popular for promoting relaxation, easing anxiety, and supporting sleep, with some encouraging evidence for a standardized oral lavender oil product for anxie...

Read the full Lavender monograph → Herb & supplement monograph

Star Anise

Star anise (Illicium verum) is a star-shaped spice widely used in cooking and traditional medicine, mostly for digestive and respiratory complaints. Human evidence for health benefits is lim...

Read the full Star Anise monograph →
Sources

Sources & How We Checked

Stomach Tonic'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 80 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.

Gentian 5 references
  1. Neubauer N, Marz RW. Placebo-controlled, randomized, double-blind, clincal trial with Sinupret sugar coated tablets on the basis of a therapy with antibiotics and decongestant nasal drops in acute sinusitis. Phytomedicine 1994;1:177-81.
  2. Marz RW, Ismail C, Popp MA. Action profile and efficacy of a herbal combination preparation for the treatment of sinusitis. Wien Med Wochenschr 1999;149:202-8.
  3. Uncini Manganelli RE, Chericoni S, Baragatti B. Ethnopharmacobotany in Tuscany: plants used as antihypertensives. Fitoterapia 2000;71:S95-100. PubMed
  4. Baragatti B, Calderone V, Testai L, et al. Vasodilator activity of crude methanolic extract of Gentiana kokiana Perr. et Song. (Gentianaceae). J Ethnopharmacol 2002;79:369-72. PubMed
  5. Sanatani M, Younus J, Stitt L, et al. Tolerability of the combination of ginger (Zingiber officinalis), gentian (Gentiana lutea) and turmeric (Curcuma longa) in patients with cancer-associated anorexia. J Complement Integr Med. 2015;12(1):57-60.

See these in context on the Gentian 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 →

Ashitaba 2 references
  1. Kwon D, Yoon S, Carter O, Bailey GS, Dashwood RH. Antioxidant and antigenotoxic activities of Angelica keiskei, Oenanthe javanica and Brassica oleracea in the Salmonella mutagenicity assay and in HCT116 human colon cancer cells. Biofactors. 2006;26(4):231
  2. Noh HM, Ahn EM, Yun JM, Cho BL, Paek YJ. Angelica keiskei Koidzumi extracts improve some markers of liver function in habitual alcohol drinkers: a randomized double-blind clinical trial. J Med Food. 2015;18(2):166-72.

See these in context on the Ashitaba monograph →

German Chamomile 15 references
  1. Subiza J, Subiza JL, Hinojosa M, et al. Anaphylactic reaction after the ingestion of chamomile tea; a study of cross-reactivity with other composite pollens. J Allergy Clin Immunol 1989;84:353-8. PubMed
  2. 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
  3. Viola H, Wasowski C, Levi de Stein M, et al. Apigenin, a component of Matricaria recutita flowers, is a central benzodiazepine receptors-ligand with anxiolytic effects. Planta Med 1995;61:213-6.
  4. van Ketel WG. Allergy to Matricaria chamomilla. Contact Dermatitis 1982;8:143. PubMed
  5. van Ketel WG. Allergy to Matricaria chamomilla. Contact Dermatitis 1987;16:50-1. PubMed
  6. Hormann HP, Korting HC. Evidence for the efficacy and safety of topical herbal drugs in dermatology: part I: anti-inflammatory agents. Phytomedicine 1994;1:161-71. PubMed
  7. Avallone R, Zanoli P, Puia G, et al. Pharmacological profile of apigenin, a flavonoid isolated from Matricaria chamomilla. Biochem Pharmacol 2000;59:1387-94. PubMed
  8. Kassi E, Papoutsi Z, Fokialakis N, et al. Greek plant extracts exhibit selective estrogen receptor modulator (SERM)-like properties. J Agric Food Chem 2004;52:6956-61. PubMed
  9. Maliakal PP, Wanwimolruk S. Effect of herbal teas on hepatic drug metabolizing enzymes in rats. J Pharm Pharmacol 2001;53:1323-9. PubMed
  10. Segal R, Pilote L. Warfarin interaction with Matricaria chamomilla. CMAJ 2006;174:1281-2. PubMed
  11. Loggia RD, Traversa U, Scarcia V, et al. Depressive effects of Chamomilla recutita (L.) Rausch, tubular flowers, on central nervous system in mice. Pharmacol Res Commun 1982;14(2):153-162. PubMed
  12. Ganzera M, Schneider P, Stuppner H. Inhibitory effects of the essential oil of chamomile (Matricaria recutita L.) and its major constituents on human cytochrome P450 enzymes. Life Sci 2006;78(8):856-861. PubMed
  13. Benito P, Rodríguez-Perez R, García F, Juste S, Moneo I, Caballero ML. Occupational allergic rhinoconjunctivitis induced by Matricaria chamomilla with tolerance of chamomile tea. J Investig Allergol Clin Immunol. 2014;24(5):369-70. No abstract available.
  14. Braga FT, Santos AC, Bueno PC, et al. Use of Chamomilla recutita in the prevention and treatment of oral mucositis in patients undergoing hematopoietic stem cell transplantation: a randomized, controlled, phase II clinical trial. Cancer Nurs 2015;38(4):32 PubMed
  15. Sarris J, Ravindran A, Yatham LN, et al. Clinician guidelines for the treatment of psychiatric disorders with nutraceuticals and phytoceuticals: The World Federation of Societies of Biological Psychiatry (WFSBP) and Canadian Network for Mood and Anxiety T

See these in context on the German Chamomile monograph →

Northern Prickly Ash 2 references
  1. McGuffin M, Hobbs C, Upton R, Goldberg A, eds. American Herbal Products Association's Botanical Safety Handbook. Boca Raton, FL: CRC Press, LLC 1997.
  2. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.

See these in context on the Northern Prickly Ash monograph →

Cardamom 2 references
  1. Mobacken, H. and Fregert, S. Allergic contact dermatitis from cardamom. Contact Dermatitis 1975;1(3):175-176. PubMed
  2. Aghasi M, Koohdani F, Qorbani M, et al. Beneficial effects of green cardamom on serum SIRT1, glycemic indices and triglyceride levels in patients with type 2 diabetes mellitus: a randomized double-blind placebo controlled clinical trial. J Sci Food Agri PubMed

See these in context on the Cardamom monograph →

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 →

Lavender 20 references
  1. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  2. Schulz V, Hansel R, Tyler VE. Rational Phytotherapy: A Physician's Guide to Herbal Medicine. Terry C. Telger, transl. 3rd ed. Berlin, GER: Springer, 1998.
  3. Akhondzadeh S, Kashani L, Fotouhi A, et al. Comparison of Lavandula angustifolia Mill. tincture and imipramine in the treatment of mild to moderate depression: a double-blind, randomized trial. Prog Neuropsychopharmacol Biol Psychiatry 2003;27:123-7. PubMed
  4. Varma S, Blackford S, Statham BN, Blackwell A. Combined contact allergy to tea tree oil and lavender oil complicating chronic vulvovaginitis. Contact Dermatitis 2000;42:309-10.
  5. Coulson IH and Khan AS. Facial 'pillow' dermatitis due to lavender oil allergy. Contact Dermatitis 1999;41(2):111. PubMed
  6. Woelk, H. and Schlafke, S. A multi-center, double-blind, randomised study of the Lavender oil preparation Silexan in comparison to Lorazepam for generalized anxiety disorder. Phytomedicine. 2010;17(2):94-99. PubMed
  7. Kasper, S., Gastpar, M., Muller, W. E., Volz, H. P., Moller, H. J., Dienel, A., and Schlafke, S. Silexan, an orally administered Lavandula oil preparation, is effective in the treatment of 'subsyndromal' anxiety disorder: a randomized, double-blind, plac
  8. Uehleke, B., Schaper, S., Dienel, A., Schlaefke, S., and Stange, R. Phase II trial on the effects of Silexan in patients with neurasthenia, post-traumatic stress disorder or somatization disorder. Phytomedicine. 6-15-2012;19(8-9):665-671. PubMed
  9. Brandao FM. Occupational allergy to lavender oil. Contact Dermatitis 1986;15(4):249-250. PubMed
  10. Rademaker M. Allergic contact dermatitis from lavender fragrance in Difflam gel. Contact Dermatitis 1994;31(1):58-59. PubMed
  11. Kasper S, Gastpar M, Müller WE, et al. Lavender oil preparation Silexan is effective in generalized anxiety disorder--a randomized, double-blind comparison to placebo and paroxetine. Int J Neuropsychopharmacol. 2014 Jun;17(6):859-69. PubMed
  12. Farshbaf-Khalili A, Kamalifard M, Namadian M. Comparison of the effect of lavender and bitter orange on anxiety in postmenopausal women: A triple-blind, randomized, controlled clinical trial. Complement Ther Clin Pract 2018;31:132-8. PubMed
  13. Bingham LJ, Tam MM, Palmer AM, Cahill JL, Nixon RL. Contact allergy and allergic contact dermatitis caused by lavender: A retrospective study from an Australian clinic. Contact Dermatitis. 2019;81(1):37-42. PubMed
  14. Donelli D, Antonelli M, Bellinazzi C, Gensini GF, Firenzuoli F. Effects of lavender on anxiety: A systematic review and meta-analysis. Phytomedicine. 2019;65:153099. PubMed
  15. Firoozeei TS, Feizi A, Rezaeizadeh H, Zargaran A, Roohafza HR, Karimi M. The antidepressant effects of lavender (Lavandula angustifolia Mill.): A systematic review and meta-analysis of randomized controlled clinical trials. Complement Ther Med 2021;59:102 PubMed
  16. Kodama T, Watanabe T, Mataki N, Kanoh S, Kichikawa Y. Acute eosinophilic pneumonia following aromatherapy with essential oil. Respir Med Case Rep 2022;37:101657. PubMed
  17. Barbaud A, Kurihara F, Raison-Peyron N, et al. Allergic contact dermatitis from essential oil in consumer products: Mode of uses and value of patch-tests with an essential oil series. Results of a French study of the DAG (dermato-allergy group of the Fren
  18. Ozer H, Sayan ZA, Baloglu I, Ozturk Y, Yonet F, Turkmen K. Unknown criminals for kidney: Acute interstitial nephritis due to lavender tea. Explore (NY) 2023. PubMed
  19. Kasper S, Volz HP, Möller HJ, et al. Lavender oil preparation Silexan is effective in mild-to-moderate major depression: a randomized, placebo- and reference-controlled trial. Eur Arch Psychiatry Clin Neurosci 2024. PubMed
  20. Simaei SR, Askari VR, Rostami M, et al. Lavender and metformin effectively propagate progesterone levels in patients with polycystic ovary syndrome: A randomized, double-blind clinical trial. Fitoterapia 2023;172:105720. PubMed

See these in context on the Lavender monograph →

Star Anise 10 references
  1. 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
  2. Anon. FDA issue advisory on star anise "teas." FDA News P03-67; September 10, 2003.
  3. Ize-Ludlow D, Ragone S, Bernstein JN, et al. Chemical composition of Chinese star anise (Illicium verum) and neurotoxicity in infants. JAMA 2004;291:562-3. PubMed
  4. Ize-Ludlow D, Ragone S, Bruck IS, et al. Neurotoxicities in infants seen with the consumption of star anise tea. Pediatrics 2004;114:e653-6. PubMed
  5. Franks A. Contact allergy to anethole in toothpaste associated with loss of taste. Contact Dermatitis 1998;38:354-5. PubMed
  6. Rudzki E, Grzywa Z. Sensitizing and irritating properties of star anise oil. Contact Dermatitis 1976;2:305-8. PubMed
  7. Garzo, Fernandez C., Gomez, Pintado P., Barrasa, Blanco A., Martinez, Arrieta R., Ramirez, Fernandez R., and Ramon, Rosa F. [Cases of neurological symptoms associated with star anise consumption used as a carminative]. An.Esp.Pediatr. 2002;57(4):290-294.
  8. Minodier, P., Pommier, P., Moulene, E., Retornaz, K., Prost, N., and Deharo, L. [Star anise poisoning in infants]. Arch Pediatr. 2003;10(7):619-621.
  9. Casanova Cuenca M, Calzado Agrasot MÁ, Mir Pegueroles C, Esteban Cantó V. New cases of star anise poisoning: Are we providing enough information? Neurologia. 2019;34(3):211-213. DOI
  10. Donner J, Ruest S. Neonate with seizures after consuming star anise tea. R I Med J. 2021 Oct 1;104(8):8-10.

See these in context on the Star Anise monograph →

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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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