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

Respiratory Syrup Ingredients & Drug Interactions

by Christopher's Original Formulas

Respiratory Syrup 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 Respiratory Syrup 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

Respiratory Syrup is a dietary supplement by Christopher's Original Formulas with 5 active ingredients. Its ingredients are commonly taken for high blood pressure, high cholesterol, heart health.Based on those ingredients, 1,003 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Garlic, organic Fennel, wildcrafted Nettle. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Respiratory Syrup by Christopher's Original Formulas

Ask about any prescription or over-the-counter medication and we check it for interactions with Respiratory Syrup by Christopher's Original Formulas — 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 Respiratory Syrup by Christopher's Original Formulas

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 Sep 10, 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 5 active ingredients.
  • “Proprietary Blend” is a proprietary blend — the label doesn't break down how much of each component you get.

Respiratory Syrup contains 5 active ingredients in a proprietary blend: garlic, organic fennel, wildcrafted mullein, wildcrafted nettle, and wildcrafted chickweed. The product also contains a base of pure apple cider vinegar as an inactive ingredient.

The blend is formulated as a liquid, making it easy to dose and absorb.

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: respiratory health and cough relief.
  • We looked for evidence on: Bronchitis, Common cold, Cough, chest congestion, sore throat, respiratory irritation.
  • The closest evidence on file: Garlic is rated "Insufficient Reliable Evidence To Rate" for Bronchitis (Natural Medicines).
  • Also on file: Garlic is rated "Insufficient Reliable Evidence To Rate" for Common cold.
  • Also on file: Fennel is rated "Insufficient Reliable Evidence To Rate" for Bronchitis, Cough.

The evidence for these ingredients is mixed. Garlic is possibly effective for diabetes, hypertension (high blood pressure), atherosclerosis, periodontitis (gum disease), and nonalcoholic fatty liver disease.

Fennel is possibly effective for dysmenorrhea (painful periods), but insufficient evidence supports it for bronchitis, anxiety, nocturnal enuresis (bedwetting), or cholera. Stinging nettle is possibly effective for diabetes, but insufficient evidence supports it for hay fever, anemia, asthma, benign prostatic hyperplasia, or gingivitis.

For mullein and chickweed, we have insufficient reliable evidence to rate their effectiveness for any condition in our data.

The evidence, ingredient by ingredient Garlic Fennel Mullein Stinging Nettle Chickweed

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 5 of the 5 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 5 of 5.
  • General safety write-ups exist for 5 of 5.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Orally, these ingredients are generally well tolerated. Garlic may cause abdominal pain, body odor, flatulence, bad breath, nausea, or allergic reactions in sensitive individuals; rare cases of increased bleeding risk have been reported.

Fennel may cause gastrointestinal discomfort, photosensitivity (increased sun sensitivity), or allergic reactions, and rarely seizures or bronchial asthma. Mullein and nettle have limited human safety data; mullein may cause dermatitis with topical exposure, and nettle may cause constipation, diarrhea, or in rare cases liver injury.

Chickweed is considered low-risk for short-term use, though high-quality safety data are limited. Fennel and nettle should be avoided during pregnancy due to insufficient safety data and possible hormone-like effects; mullein and chickweed also lack adequate pregnancy safety information.

Breastfeeding safety is not established for mullein, nettle, or chickweed, so discuss with your doctor or pharmacist before using while nursing.

Side effects, ingredient by ingredient Garlic Fennel Mullein Stinging Nettle Chickweed

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?
  • 4 of the 5 matched ingredients can interact with medications — Garlic, Fennel, Mullein, Stinging Nettle.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications; lithium.
  • For scale: 1,004 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 any blood thinners or antiplatelet drugs (Moderate risk), antidiabetes drugs, antihypertensive drugs, diuretics, lithium, or drugs metabolized by CYP3A4 or CYP2E1 (all Moderate risk). If you take warfarin specifically, ciprofloxacin, protease inhibitors, tamoxifen, contraceptives, or hormone replacement therapy, these also need review (Moderate risk).

Mullein has a Minor interaction with blood thinners as well.

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 syrup may appeal to someone looking to support respiratory health with herbal ingredients, but it's not a first-line treatment for any condition. If you take blood thinners (including warfarin), diabetes drugs, blood pressure medications, contraceptives, hormone therapy, diuretics, lithium, or protease inhibitors, you need to check with your doctor or pharmacist before using it — the interactions are real and may affect how your drugs work.

Pregnant or breastfeeding? Talk it over with your healthcare provider first.

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

Assessment coverage: 5 of 5 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Apr 25, 2019.

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 Respiratory Syrup, straight from the product label.

Brand Christopher's Original Formulas
Barcode (UPC) 084783885368
Net contents 4 fl. Oz.; 118 mL
Market status On market
Date entered into DSLD Apr 25, 2019
DSLD ID 200524
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 Respiratory Syrup by Christopher's Original Formulas, 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 Teaspoon(s)
Maximum serving Sizes:
1 Teaspoon(s)
Servings per container
24
UPC/BARCODE
084783885368
IngredientAmount% DV
Proprietary Blend0 NP--
Garlic0 NP--
organic Fennel0 NP--
wildcrafted Mullein0 NP--
wildcrafted Nettle0 NP--
wildcrafted Chickweed0 NP--

Other ingredients: A base of, pure Apple Cider Vinegar

Tap any ingredient to jump to its full detail below.

Label statements
These statements are the manufacturer’s wording, reproduced from the product label — the label is saying it, not HelloPharmacist. We don’t verify or endorse them.
Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take 1 teaspoon 3 times a day, or as directed by your health care professional.

Precautions

Do not use during pregnancy or while nursing

Storage

Refrigerate after opening.

General Statements

Proudly Made in The U.S.A.

Brand IP Statement(s)

2016 Wholistic Botanicals L.L.C All Rights Reserved

John R. Christopher

FDA Statement of Identity

Dietary Supplement

Formulation

No added fillers or chemicals

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 disease

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

See for yourself

Respiratory Syrup by Christopher's Original Formulas label

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

Respiratory Syrup 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 Respiratory Syrup by Christopher's Original Formulas

These are the 5 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Teaspoon(s) Dosage formLiquid Servings per container24 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

0 NP per serving

Other (inactive) ingredients: A base of, Pure Apple Cider Vinegar. These complete the product’s ingredient list but are not active constituents.

Interaction report

Respiratory Syrup by Christopher's Original Formulas Drug Interactions

Want to check YOUR meds against Respiratory Syrup?

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
1,003Drugs
1,003 Moderate

Ingredients driving the most interactions

Garlic 989
organic Fennel 740
wildcrafted Nettle 164
wildcrafted Mullein 122

Individual Drug Interactions

The ingredients in Respiratory Syrup interact with 1,003 drugs. Click any drug to see the details.

4 of the 5 ingredients in Respiratory Syrup interact with drugs. Each result below shows which ingredient is responsible. Garlic organic Fennel wildcrafted Nettle wildcrafted Mullein

Each ingredient & the kinds of drugs it affects

For each ingredient in Respiratory Syrup 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.

Garlic12 drug types · 989 drugs

Anticoagulant/Antiplatelet Drugs

Garlic may have antiplatelet effects and may increase the risk of bleeding if used with anticoagulant or antiplatelet drugs.
Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, taking garlic with antidiabetes drugs might increase the risk of hypoglycemia.
Clinical research suggests that garlic and garlic extract lower blood glucose levels in healthy and diabetic individuals.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking garlic with antihypertensive drugs might increase the risk of hypotension.
In human research, both garlic and garlic extracts have blood pressure-lowering effects.

Likelihood Possible Evidence D
Atazanavir (Reyataz)

Theoretically, garlic might decrease levels and effects of atazanavir.
In a case report, a patient consuming six stir-fried garlic cloves three times weekly developed suboptimal atazanavir levels and increases in HIV viral load. While the exact cause of this interaction is unclear, there is speculation that garlic might decrease the intestinal absorption of atazanavir or increase its metabolism by inducing cytochrome P450 3A4 (CYP3A4). Until more is known, advise patients not to consume large amounts of garlic while taking atazanavir.

Likelihood Possible Evidence D
Cytochrome P450 2E1 (Cyp2E1) Substrates

Garlic might increase levels of drugs metabolized by CYP2E1.
Clinical research suggests garlic oil can inhibit the activity of CYP2E1 by 39%. Use garlic oil cautiously in patients taking drugs metabolized by these enzymes.

Likelihood Probable Evidence B
Cytochrome P450 3A4 (Cyp3A4) Substrates

Theoretically, garlic products containing allicin might induce intestinal CYP3A4 and inhibit hepatic CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
Some human research suggests that garlic may induce INTESTINAL CYP3A4, reducing levels of drugs metabolized by this enzyme. This is primarily based on a study showing that taking a specific allicin-containing garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induced CYP3A4 in the gut mucosa. Another study shows that giving docetaxel intravenously, bypassing the CYP3A4 enzymes in the gut mucosa, along with the same specific garlic product for 12 consecutive days, does not affect docetaxel levels. Conversely, there is concern that garlic may inhibit HEPATIC CYP3A4. In a single case report, increased tacrolimus levels and liver injury occurred in a liver transplant patient after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days. Several other studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin.

Likelihood Possible Evidence B
Isoniazid

Theoretically, garlic might decrease levels of isoniazid.
Animal research suggests that an aqueous extract of garlic reduces isoniazid levels by about 65%. Garlic reduced the maximum concentration (Cmax) and area under the curve (AUC), but not the half-life, of isoniazid. This suggests that garlic extract might inhibit isoniazid absorption across the intestinal mucosa; however, the exact mechanism of this potential interaction is not known.

Likelihood Possible Evidence D
Protease Inhibitors (Pis)

Theoretically, garlic products containing allicin might decrease levels of PIs.
Protease inhibitors are metabolized by cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4, reducing plasma levels of protease inhibitors. This is primarily based on a study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces levels of saquinavir, a PI, by approximately 50%. It is speculated that the allicin constituent induce CYP3A4 in the gut mucosa. Several studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin.

Likelihood Possible Evidence B
Saquinavir (Fortovase, Invirase)

Theoretically, garlic containing allicin might decrease levels of saquinavir.
Saquinavir is a substrate of cytochrome P450 3A4 (CYP3A4) isoenzymes. There is concern that garlic products containing allicin might induce intestinal CYP3A4 and cause subtherapeutic levels of saquinavir. This is primarily based on a pharmacokinetic study showing that taking a specific garlic product (GarliPure Maximum Allicin Formula, Natrol Inc.) twice daily for 3 days reduces saquinavir levels by approximately 50%. It is speculated that the allicin constituent induces CYP3A4 in the gut mucosa. Several pharmacokinetic studies have evaluated the impact of other garlic formulations on CYP3A4 substrates and have found no effect. Most of the products in these studies provided little or no allicin. Until more is known about this potential interaction, use garlic containing allicin cautiously in patients taking saquinavir.

Likelihood Possible Evidence B
Sofosbuvir (Sovaldi)

Theoretically, taking garlic with sofosbuvir might decrease its effectiveness.
Animal research in rats shows that giving aged garlic extract 120 mg/kg orally daily for 14 days decreases the area under the concentration time curve (AUC) after a single sofosbuvir dose of 40 mg/kg by 36%, increases the clearance by 63%, and decreases the plasma concentrations at 1 and 8 hours by 35% and 58%, respectively. This interaction is hypothesized to be due to induction of intestinal P-glycoprotein expression by garlic.

Likelihood Possible Evidence D
Tacrolimus (Prograf)

Theoretically, garlic might increase levels of tacrolimus.
In one case report, a liver transplant patient taking tacrolimus experienced increased tacrolimus levels and liver injury after taking a specific garlic supplement (Garlicin Cardio, Nature's Way) at up to three times the manufacturer recommended dose for 7 days. It is speculated that garlic inhibited hepatic cytochrome P450 3A4 (CYP3A4), which increased plasma levels of tacrolimus.

Likelihood Possible Evidence B
Warfarin (Coumadin)

Theoretically, garlic might increase the risk of bleeding with warfarin.
Raw garlic and a variety of garlic extracts have antiplatelet activity and can increase prothrombin time. In addition, there is a report of two patients who experienced an increase in a previously stabilized international normalized ratio (INR) with concomitant garlic and warfarin use. However, this report has been subsequently debated due to limited clinical information. Other clinical studies have not identified an effect of garlic on INR, warfarin pharmacokinetics, or bleeding risk. More evidence is needed to determine the safety of using garlic with warfarin.

Likelihood Possible Evidence D
Garlic full monograph & interactions

organic 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
organic Fennel full monograph & interactions

wildcrafted Nettle4 drug types · 164 drugs

Antidiabetes Drugs

Theoretically, stinging nettle might have additive effects with antidiabetes drugs.
Clinical research shows that stinging nettle might decrease blood glucose levels in patients with diabetes.

Likelihood Possible Evidence B
Diuretic Drugs

Theoretically, combining stinging nettle with diuretic drugs may have additive effects.
Animal research suggests that the above ground parts and roots of stinging nettle may have a diuretic effect.

Likelihood Possible Evidence D
Lithium

Theoretically, stinging nettle might reduce excretion and increase levels of lithium.
Animal research suggests that stinging nettle has diuretic and natriuretic properties, which could alter the excretion of lithium. The dose of lithium might need to be decreased.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is some concern that stinging nettle might decrease the effects of anticoagulant drugs such as warfarin.
Stinging nettle contains a significant amount of vitamin K. When taken in large quantities, this might interfere with the activity of warfarin.

Likelihood Possible Evidence D
wildcrafted Nettle full monograph & interactions

wildcrafted Mullein1 drug type · 122 drugs

Anticoagulant/Antiplatelet Drugs

Lab tests on extracts from different parts of common and dense-flowered mullein plants show that they do have some blood-thinning effects, as they increase the time it takes for blood to clot. This is likely due to at least one of the known constituents of muellein, triterpenoid saponins. However, the effects appear to be mild and results have been inconsistent. Extracts from different plant parts have been show to have varying anticoagulant strengths, with water-based ones being more potent than alcohol-based extracts.

Likelihood Unlikely Evidence A
wildcrafted Mullein full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Respiratory Syrup, from the product label.

Christopher's Original Formulas

See all Christopher's Original Formulas products
Name
Wholistic Botanicals L.L.C.
City
Spanish Fork
State
UT
ZipCode
84660
Phone Number
1-800-453-1406
Web Address
www.drchristopher.com
Pharmacist Counseling Corner

Respiratory Syrup by Christopher's Original Formulas: Common Questions

Does Respiratory Syrup by Christopher's Original Formulas interact with any medications?
Yes. Based on its ingredients, Respiratory Syrup has a known interaction with 1,003 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Respiratory Syrup contains 5 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.
Does this syrup actually help with cough or bronchitis?
Garlic is possibly effective for respiratory and inflammation concerns. Mullein and fennel have insufficient evidence in our data to rate their effectiveness for cough or bronchitis specifically. This product isn't proven to treat these conditions — if you have a persistent cough or bronchitis, talk to your doctor.
Is it safe to take while pregnant?
No, not without your doctor's approval. Fennel and nettle should be avoided during pregnancy due to insufficient safety data and possible hormone-like effects. Mullein and chickweed also lack adequate pregnancy safety information. Garlic is rated as possibly unsafe in pregnancy. Discuss with your obstetrician or midwife before use.
Can I take this while breastfeeding?
Safety while breastfeeding has not been established for mullein, nettle, or chickweed, so avoidance is the safer choice until you talk with your doctor. Garlic is rated as likely safe while breastfeeding, but get personalized guidance from your pediatrician or lactation specialist before starting any supplement.
What are the most common side effects?
Garlic may cause stomach upset, flatulence, bad breath, or body odor. Fennel may cause gastrointestinal discomfort or make your skin more sun-sensitive. Nettle may cause constipation or diarrhea. If you develop a rash, difficulty breathing, or other allergic symptoms, stop and contact your healthcare provider.
Why does this product contain apple cider vinegar?
Apple cider vinegar is used as a base to preserve and carry the herbal ingredients. It's an inactive ingredient — the active components are the garlic, fennel, mullein, nettle, and chickweed.
Is there any risk if I'm on blood thinners like warfarin?
Yes. Garlic, fennel, mullein, and nettle all have documented interactions with blood thinners or warfarin specifically. Garlic and nettle may interfere with how warfarin works, and garlic can raise your bleeding risk. Do not start this product without checking with your doctor or pharmacist first — they may need to monitor your INR or adjust your dose.

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

Not sure if Respiratory Syrup 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.

Respiratory Syrup label
Go deeper

The Full Monographs Behind Respiratory Syrup’s Ingredients

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

Herb & supplement monograph

Garlic

Interacts with 989 drugs

Garlic is a common food and supplement that may modestly help with blood pressure and cholesterol, though the evidence is mixed and effects are usually small. It is generally safe in food am...

Read the full Garlic 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

Mullein

Interacts with 122 drugs

Mullein is a traditional herbal remedy most often used as a tea or syrup to soothe coughs, sore throats, and respiratory irritation. High-quality human studies are lacking, so its benefits a...

Read the full Mullein monograph → Herb & supplement monograph

Stinging Nettle

Interacts with 164 drugs

Stinging nettle is a common plant used as food and in traditional medicine, most often for prostate symptoms, allergies, and joint pain. The evidence is mixed and mostly preliminary, so it i...

Read the full Stinging Nettle monograph → Herb & supplement monograph

Chickweed

Chickweed is a common edible wild plant traditionally used on the skin for itching and minor irritation, and taken as a tea or tincture for various complaints. Solid human studies are lackin...

Read the full Chickweed monograph →
Sources

Sources & How We Checked

Respiratory Syrup'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 200 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.

Garlic 154 references
  1. Silagy CA, Neil HA. A meta-analysis of the effect of garlic on blood pressure. J Hypertens 1994;12:463-8. DOI
  2. McMahon FG, Vargas R. Can garlic lower blood pressure? A pilot study. Pharmacotherapy 1993;13:406-7. DOI
  3. Auer W, Eiber A, Hertkorn E, et al. Hypertension and hyperlipidaemia: garlic helps in mild cases. Br J Clin Pract Suppl 1990;69:3-6.
  4. Garty BZ. Garlic burns. Pediatrics 1993;91:658-9.
  5. Rose KD, Croissant PD, Parliament CF, Levin MB. Spontaneous spinal epidural hematoma with associated platelet dysfunction from excessive garlic ingestion: a case report. Neurosurg 1990;26:880-2. PubMed
  6. Burnham BE. Garlic as a possible risk for postoperative bleeding. Plast Reconstr Surg 1995;95:213.
  7. Sunter WH. Warfarin and garlic. Pharm J 1991;246:722.
  8. Berthold HK, Sudhop T, von Bergmann K. Effect of a garlic oil preparation on serum lipoproteins and cholesterol metabolism. JAMA 1998;279:1900-2.
  9. Steiner M, Khan AH, Holbert D, Lin RI. A double-blind crossover study in moderately hypercholesterolemic men that compared the effect of aged garlic extract and placebo administration on blood lipids. Am J Clin Nutr 1996;64:866-70. PubMed
  10. Steiner M, Lin RS. Changes in platelet function and susceptibility of lipoproteins to oxidation associated with administration of aged garlic extract. J Cardiovasc Pharmacol 1998;31:904-8. PubMed
  11. Gwilt PR, Lear CL, Tempero MA, et al. The effect of garlic extract on human metabolism of acetaminophen. Cancer Epidemiol Biomarkers Prev 1994;3:155-60.
  12. Rahman K, Billington D. Dietary supplementation with aged garlic extract inhibits ADP-induced platelet aggregation in humans. J Nutr 2000;130:2662-5. PubMed
  13. Bloch AS. Pushing the Envelope of Nutrition Support: Complementary Therapies. Nutrition 2000;16:236-9. PubMed
  14. Steiner M, Li W. Aged garlic extract, a modulator of cardiovascular risk factors: a dose-finding study on the effects of AGE on platelet functions. J Nutr 2001;131:980S-4S. PubMed
  15. Mader FH. Treatment of hyperlipidaemia with garlic-powder tablets. Evidence from the German Association of General Practitioners' multicentric placebo-controlled double-blind study. Arzneimittelforschung 1990;40:1111-6.
  16. Vorberg G, Schneider B. Therapy with garlic: results of a placebo-controlled, double-blind study. Br J Clin Pract Symp Suppl 1990;69:7-11.
  17. Simons LA, Balasubramaniam S, von Konigsmark M, et al. On the effect of garlic on plasma lipids and lipoproteins in mild hypercholesterolaemia. Atherosclerosis 1995;113:219-25. PubMed
  18. Neil HA, Silagy CA, Lancaster T, et al. Garlic powder in the treatment of moderate hyperlipidaemia: a controlled trial and meta-analysis. J R Coll Physicians Lond 1996;30:329-34. DOI
  19. Koscielny J, Klussendorf D, Latza R, et al. The antiatherosclerotic effect of Allium sativum. Atherosclerosis 1999;144:237-49. PubMed
  20. Kiesewetter H, Jung F, Jung EM, et al. Effects of garlic coated tablets in peripheral arterial occlusive disease. Clin Investig 1993;71:383-6. PubMed
  21. Kiesewetter H, Jung F, Jung EM, et al. Effect of garlic on platelet aggregation in patients with increased risk of juvenile ischaemic attack. Eur J Clin Pharmacol 1993;45:333-6. PubMed
  22. Legnani C, Frascaro M, Guazzaloca G, et al. Effects of a dried garlic preparation on fibrinolysis and platelet aggregation in healthy subjects. Arzneimittelforschung 1993;43:119-22.
  23. Mennella JA, Johnson A, Beauchamp GK. Garlic ingestion by pregnant women alters the odor of amniotic fluid. Chem Senses 1995;20:207-9. PubMed
  24. Mennella JA, Beauchamp GK. Maternal diet alters the sensory qualities of human milk and the nursling's behavior. Pediatrics 1991;88:737-44. DOI
  25. Mennella JA, Beauchamp GK. The effects of repeated exposure to garlic-flavored milk on the nursling's behavior. Pediatr Res 1993;34:805-8. PubMed
  26. Cronin E. Dermatitis of the hands in caterers. Contact Dermatitis 1987;17:265-9. PubMed
  27. Lee TY, Lam TH. Contact dermatitis due to topical treatment with garlic in Hong Kong. Contact Dermatitis 1991;24:193-6. PubMed
  28. Bruynzeel DP. Bulb dermatitis. Dermatological problems in the flower bulb industries. Contact Dermatitis 1997;37:70-7.
  29. Stevinson C, Pittler MH, Ernst E. Garlic for treating hypercholesterolemia: a meta-analysis of randomized clinical trials. Ann Intern Med 2000;133:420-9. PubMed
  30. Ackermann RT, Mulrow CD, Ramirez G, et al. Garlic shows promise for improving some cardiovascular risk factors. Arch Intern Med 2001;161:813-24. PubMed
  31. Piscitelli SC, Burstein AH, Welden N, et al. The effect of garlic supplements on the pharmacokinetics of saquinavir. Clin Infect Dis 2002;34:234-8. PubMed
  32. Ziaei S, Hantoshzadeh S, Rezasoltani P, Lamyian M. The effect of garlic tablet on plasma lipids and platelet aggregation in nulliparous pregnants at high risk of preeclampsia. Eur J Obstet Gynecol Reprod Biol 2001;99:201-6.. PubMed
  33. Markowitz JS, Devane CL, Chavin KD, et al. Effects of garlic (Allium sativum L.) supplementation on cytochrome P450 2D6 and 3A4 activity in healthy volunteers. Clin Pharmacol Ther 2003;74:170-7.. PubMed
  34. Josling P. Preventing the common cold with a garlic supplement: a double-blind, placebo-controlled survey. Adv Ther 2001;18:189-93. PubMed
  35. Gurley BJ, Gardner SF, Hubbard MA, et al. Cytochrome P450 phenotypic ratios for predicting herb-drug interactions in humans. Clin Pharmacol Ther 2002;72:276-87.. PubMed
  36. Farnsworth N, Bingel A, Cordell G, et al. Potential value of plants as sources of new antifertility agents I. J Pharm Sci 1975;64:535-98. DOI
  37. Carden SM, Good WV, Carden PA, Good RM. Garlic and the strabismus surgeon. Clin Experiment Ophthalmol 2002;30:303-4. PubMed
  38. Kanerva L, Estlander T, Jolanki R. Occupational allergic contact dermatitis from spices. Contact Dermatitis 1996;35:157-62. PubMed
  39. Dehghani F, Merat A, Panjehshahin MR, Handjani F. Healing effect of garlic extract on warts and corns. Int J Dermatol 2005;44:612-5. PubMed
  40. Dhamija P, Malhotra S, Pandhi P. Effect of oral administration of crude aqueous extract of garlic on pharmacokinetic parameters of isoniazid and rifampicin in rabbits. Pharmacology 2006;77:100-4. PubMed
  41. Macan H, Uykimpang R, Alconcel M, et al. Aged garlic extract may be safe for patients on warfarin therapy. J Nutr 2006;136(3 Suppl):793S-795S. PubMed
  42. Hubbard VG, Goldsmith P. Garlic-fingered chefs. Contact Dermatitis 2005;52:165-6. PubMed
  43. Mohammed Abdul MI, Jiang X, Williams KM, et al. Pharmacodynamic interaction of warfarin with cranberry but not with garlic in healthy subjects. Br J Pharmacol 2008;154:1691-700. PubMed
  44. Ried K, Frank OR, Stocks NP, et al. Effect of garlic on blood pressure: A systematic review and meta-analysis. BMC Cardiovasc Disord 2008;8:13. PubMed
  45. Cox MC, Low J, Lee J, et al. Influence of garlic (Allium sativum) on the pharmacokinetics of docetaxel. Clin Cancer Res 2006;12:4636-40.
  46. van der Walt, A., Lopata, A. L., Nieuwenhuizen, N. E., and Jeebhay, M. F. Work-related allergy and asthma in spice mill workers - The impact of processing dried spices on IgE reactivity patterns. Int Arch.Allergy Immunol. 2010;152(3):271-278. PubMed
  47. Huang, J., Frohlich, J., and Ignaszewski, A. P. The impact of dietary changes and dietary supplements on lipid profile. Can J Cardiol 2011;27(4):488-505. PubMed
  48. Hasani-Ranjbar, S., Nayebi, N., Moradi, L., Mehri, A., Larijani, B., and Abdollahi, M. The efficacy and safety of herbal medicines used in the treatment of hyperlipidemia; a systematic review. Curr.Pharm.Des 2010;16(26):2935-2947. PubMed
  49. Eming, S. A., Piontek, J. O., Hunzelmann, N., Rasokat, H., and Scharffetter-Kachanek, K. Severe toxic contact dermatitis caused by garlic. Br J Dermatol. 1999;141(2):391-392. PubMed
  50. Seuri, M., Taivanen, A., Ruoppi, P., and Tukiainen, H. Three cases of occupational asthma and rhinitis caused by garlic. Clin Exp.Allergy 1993;23(12):1011-1014. PubMed
  51. Rafaat, M. and Leung, A. K. Garlic burns. Pediatr Dermatol. 2000;17(6):475-476.
  52. Vaes, L. P. and Chyka, P. A. Interactions of warfarin with garlic, ginger, ginkgo, or ginseng: nature of the evidence. Ann Pharmacother 2000;34(12):1478-1482. PubMed
  53. Hviid, K. and Alsbjorn, B. ["Burns" caused by local application of garlic]. Ugeskr.Laeger 12-11-2000;162(50):6853-6854.
  54. Baruchin, A. M., Sagi, A., Yoffe, B., and Ronen, M. Garlic burns. Burns 2001;27(7):781-782.
  55. Pereira, F., Hatia, M., and Cardoso, J. Systemic contact dermatitis from diallyl disulfide. Contact Dermatitis 2002;46(2):124. PubMed
  56. Hughes, T. M., Varma, S., and Stone, N. M. Occupational contact dermatitis from a garlic and herb mixture. Contact Dermatitis 2002;47(1):48. PubMed
  57. Dillon, S. A., Burmi, R. S., Lowe, G. M., Billington, D., and Rahman, K. Antioxidant properties of aged garlic extract: an in vitro study incorporating human low density lipoprotein. Life Sci. 2-21-2003;72(14):1583-1594. PubMed
  58. Groppo, F. C., Ramacciato, J. C., Simoes, R. P., Florio, F. M., and Sartoratto, A. Antimicrobial activity of garlic, tea tree oil, and chlorhexidine against oral microorganisms. Int.Dent.J. 2002;52(6):433-437. PubMed
  59. Lachter, J., Babich, J. P., Brookman, J. C., and Factor, A. Y. Garlic: a way out of work. Mil.Med 2003;168(6):499-500. DOI
  60. Hjorth, N. and Roed-Petersen, J. Occupational protein contact dermatitis in food handlers. Contact Dermatitis 1976;2(1):28-42. PubMed
  61. van Ketel, W. G. and de Haan, P. Occupational eczema from garlic and onion. Contact Dermatitis 1978;4(1):53-54. PubMed
  62. McFadden, J. P., White, I. R., and Rycroft, R. J. Allergic contact dermatitis from garlic. Contact Dermatitis 1992;27(5):333-334. PubMed
  63. Tanamai, J., Veeramanomai, S., and Indrakosas, N. The efficacy of cholesterol-lowering action and side effects of garlic enteric coated tablets in man. J Med Assoc.Thai. 2004;87(10):1156-1161.
  64. Ashraf, R., Aamir, K., Shaikh, A. R., and Ahmed, T. Effects of garlic on dyslipidemia in patients with type 2 diabetes mellitus. J Ayub.Med Coll.Abbottabad. 2005;17(3):60-64.
  65. Laing, M. E., Barry, J., Buckley, A. M., and Murphy, G. M. Immediate and delayed hypersensitivity reactions to food and latex in a chef. Contact Dermatitis 2006;55(3):193-194. PubMed
  66. Friedman, T., Shalom, A., and Westreich, M. Self-inflicted garlic burns: our experience and literature review. Int.J Dermatol. 2006;45(10):1161-1163. PubMed
  67. van Doorn, M. B., Espirito Santo, S. M., Meijer, P., Kamerling, I. M., Schoemaker, R. C., Dirsch, V., Vollmar, A., Haffner, T., Gebhardt, R., Cohen, A. F., Princen, H. M., and Burggraaf, J. Effect of garlic powder on C-reactive protein and plasma lipids
  68. Ekeowa-Anderson, A. L., Shergill, B., and Goldsmith, P. Allergic contact cheilitis to garlic. Contact Dermatitis 2007;56(3):174-175. PubMed
  69. Gadkari JV, Joshi VD. Effect of ingestion of raw garlic on serum cholesterol level, clotting time and fibrinolytic activity in normal subjects. J Postgrad.Med 1991;37:128-131.
  70. McFadden, J. P., White, J. M., Basketter, D. A., and Kimber, I. Reduced allergy rates in atopic eczema to contact allergens used in both skin products and foods: atopy and the 'hapten-atopy hypothesis'. Contact Dermatitis 2008;58(3):156-158. PubMed
  71. Lembo, G., Balato, N., Patruno, C., Auricchio, L., and Ayala, F. Allergic contact dermatitis due to garlic (Allium sativum). Contact Dermatitis 1991;25(5):330-331.
  72. Bordel-Gomez, M. T. and Miranda-Romero, A. Sensitivity to diallyl disulfide in a Spanish population. Contact Dermatitis 2008;59(2):125-126. PubMed
  73. Reinhart, K. M., Coleman, C. I., Teevan, C., Vachhani, P., and White, C. M. Effects of garlic on blood pressure in patients with and without systolic hypertension: a meta-analysis. Ann.Pharmacother. 2008;42(12):1766-1771. PubMed
  74. Bagga, S., Thomas, B. S., and Bhat, M. Garlic burn as self-inflicted mucosal injury--a case report and review of the literature. Quintessence.Int. 2008;39(6):491-494.
  75. Shakeel, M., Trinidade, A., McCluney, N., and Clive, B. Complementary and alternative medicine in epistaxis: a point worth considering during the patient's history. Eur.J.Emerg.Med. 2010;17(1):17-19. PubMed
  76. Smyth, A. R., Cifelli, P. M., Ortori, C. A., Righetti, K., Lewis, S., Erskine, P., Holland, E. D., Givskov, M., Williams, P., Camara, M., Barrett, D. A., and Knox, A. Garlic as an inhibitor of Pseudomonas aeruginosa quorum sensing in cystic fibrosis--a p
  77. Russell, J. E. Chinese complementary therapy for stress causing bilateral chemical burns to the feet. Emerg.Med.J. 2010;27(10):787. PubMed
  78. Adachi, A. [Two cases of eosinophilic gastroenteritis whose causative allergens are usefully diagnosed by patch test]. Arerugi 2010;59(5):545-551.
  79. Ried, K., Frank, O. R., and Stocks, N. P. Aged garlic extract lowers blood pressure in patients with treated but uncontrolled hypertension: a randomised controlled trial. Maturitas 2010;67(2):144-150. PubMed
  80. Hansanugrum, A. and Barringer, S. A. Effect of milk on the deodorization of malodorous breath after garlic ingestion. J.Food Sci. 8-1-2010;75(6):C549-C558. PubMed
  81. Hurley, M. N., Forrester, D. L., and Smyth, A. R. Antibiotic adjuvant therapy for pulmonary infection in cystic fibrosis. Cochrane.Database.Syst.Rev. 2010;(10):CD008037. PubMed
  82. Nahas, R. and Balla, A. Complementary and alternative medicine for prevention and treatment of the common cold. Can.Fam.Physician 2011;57(1):31-36.
  83. Takeuchi, S., Matsuzaki, Y., Ikenaga, S., Nishikawa, Y., Kimura, K., Nakano, H., and Sawamura, D. Garlic-induced irritant contact dermatitis mimicking nail psoriasis. J.Dermatol. 2011;38(3):280-282. PubMed
  84. Davis, L. E., Shen, J. K., and Cai, Y. Antifungal activity in human cerebrospinal fluid and plasma after intravenous administration of Allium sativum. Antimicrob.Agents Chemother. 1990;34(4):651-653. PubMed
  85. Ashraf, R., Khan, R. A., and Ashraf, I. Garlic (Allium sativum) supplementation with standard antidiabetic agent provides better diabetic control in type 2 diabetes patients. Pak.J.Pharm.Sci. 2011;24(4):565-570.
  86. Bakhshi, M., Taheri, J. B., Shabestari, S. B., Tanik, A., and Pahlevan, R. Comparison of therapeutic effect of aqueous extract of garlic and nystatin mouthwash in denture stomatitis. Gerodontology. 2012;29(2):e680-e684. PubMed
  87. Kianoush, S., Balali-Mood, M., Mousavi, S. R., Moradi, V., Sadeghi, M., Dadpour, B., Rajabi, O., and Shakeri, M. T. Comparison of therapeutic effects of garlic and d-Penicillamine in patients with chronic occupational lead poisoning. Basic Clin.Pharmacol
  88. Filobbos, G., Chapman, T., and Gesakis, K. Iatrogenic burns from garlic. J.Burn Care Res. 2012;33(1):e21. PubMed
  89. Nantz, M. P., Rowe, C. A., Muller, C. E., Creasy, R. A., Stanilka, J. M., and Percival, S. S. Supplementation with aged garlic extract improves both NK and gammadelta-T cell function and reduces the severity of cold and flu symptoms: a randomized, double
  90. Fedder, S. L. Spinal epidural hematoma and garlic ingestion. Neurosurgery 1990;27(4):659. DOI
  91. Lissiman, E., Bhasale, A. L., and Cohen, M. Garlic for the common cold. Cochrane.Database.Syst.Rev. 2012;3:CD006206. PubMed
  92. Kaplan, B., Schewach-Millet, M., and Yorav, S. Factitial dermatitis induced by application of garlic. Int J Dermatol. 1990;29(1):75-76. PubMed
  93. Harenberg, J., Giese, C., and Zimmermann, R. Effect of dried garlic on blood coagulation, fibrinolysis, platelet aggregation and serum cholesterol levels in patients with hyperlipoproteinemia. Atherosclerosis 1988;74(3):247-249. PubMed
  94. Parish, R. A., McIntire, S., and Heimbach, D. M. Garlic burns: a naturopathic remedy gone awry. Pediatr.Emerg.Care 1987;3(4):258-260.
  95. Bojs, G. and Svensson, A. Contact allergy to garlic used for wound healing. Contact Dermatitis 1988;18(3):179-181. PubMed
  96. Bleumink, E. and Nater, J. P. Contact dermatitis to garlic; crossreactivity between garlic, onion and tulip. Arch.Dermatol.Forsch 8-15-1973;247(2):117-124. PubMed
  97. Yoshikawa, K., Hadame, K., Saitoh, K., and Hijikata, T. Patch tests with common vegetables in hand dermatitis patients. Contact Dermatitis 1979;5(4):274-275. PubMed
  98. Bleumink, E., Doeglas, H. M., Klokke, A. H., and Nater, J. P. Allergic contact dermatitis to garlic. Br.J Dermatol. 1972;87(1):6-9. PubMed
  99. Papageorgiou, C., Corbet, J. P., Menezes-Brandao, F., Pecegueiro, M., and Benezra, C. Allergic contact dermatitis to garlic (Allium sativum L.). Identification of the allergens: the role of mono-, di-, and trisulfides present in garlic. A comparative stu DOI
  100. anonymous. Garlic in cryptococcal meningitis: a preliminary report of 21 cases. Chin Med J (Engl.) 1980;93(2):123-126.
  101. Szybejko, J., Zukowski, A., and Herbec, R. [Unusual cause of obturation of the small intestine]. Wiad.Lek. 4-15-1982;35(2):163-164.
  102. Mitchell, J. C. Contact sensitivity to garlic (Allium). Contact Dermatitis 1980;6(5):356-357. PubMed
  103. German, K., Kumar, U., and Blackford, H. N. Garlic and the risk of TURP bleeding. Br J Urol 1995;76(4):518. PubMed
  104. Petry, J. J. Garlic and postoperative bleeding. Plast.Reconstr.Surg 1995;96(2):483-484. PubMed
  105. Canduela, V., Mongil, I., Carrascosa, M., Docio, S., and Cagigas, P. Garlic: always good for the health? Br J Dermatol. 1995;132(1):161-162. PubMed
  106. Farrell, A. M. and Staughton, R. C. Garlic burns mimicking herpes zoster. Lancet 4-27-1996;347(9009):1195. PubMed
  107. Delaney, T. A. and Donnelly, A. M. Garlic dermatitis. Austr J Dermatol 1996;37(2):109-110.
  108. Ruocco, V., Brenner, S., and Lombardi, M. L. A case of diet-related pemphigus. Dermatology 1996;192(4):373-374. PubMed
  109. Jain, R. C. Effect of garlic on serum lipids, coagulability and fibrinolytic activity of blood. Am J Clin Nutr 1977;30(9):1380-1381. PubMed
  110. Rance, F. and Dutau, G. Labial food challenge in children with food allergy. Pediatr Allergy Immunol. 1997;8(1):41-44. PubMed
  111. Roberge, R. J., Leckey, R., Spence, R., and Krenzelok, E. J. Garlic burns of the breast. Am J Emerg.Med 1997;15(5):548. PubMed
  112. Kumar, M. and Berwal, J. S. Sensitivity of food pathogens to garlic (Allium sativum). J Appl.Microbiol. 1998;84(2):213-215. PubMed
  113. Bimmermann A, Weingart K, and Schwartzkopff W. Allium sativum: Studie zur Wirksamkeit bei Hyperlipoproteinamie. Therapiewoche 1988;38:3885-3890.
  114. Czerny B and Samochowiec J. Klinische Untersuchungen mit einem Knoblauch-Lezithin-Präparat. Arztezeitschr Naturheilverf 1996;37:126-129.
  115. Yeh YY, Lin RI, Yeh SM, and et al. Garlic reduces plasma cholesterol in hypercholesterolemic men maintaining habitual diets. In: Ohigashi H, Osawa T, Terao J, and et al. Food Factors for Cancer Prevention. Tokyo, Japan: Springer-Verlag;1997. DOI
  116. Edelstein AJ and Johnstown PA. Dermatitis caused by garlic. Arch Dermatol 1950;61:111. PubMed
  117. Fleischer S, Bayerl C, and Jung EG. [Occupational allergic hand dermatitis to garlic in a pizza baker]. Aktuelle Dermatol 1996;22:278-279.
  118. Gaddoni G, Selvi M, Resta F, and et al. Allergic contact dermatitis to garlic in a cook. Ann Ital Dermatol Clin Sperimentale 1994;48:120-121.
  119. Ince DI, Sonmez GT, and Ince ML. Effects garlic on aerobic performance. Turkish Journal of Medical Sciences 2000;30(6):557-561.
  120. Soltani PR. Preecampisia [sic] is an important complication of pregnancy which can result in morbidity and mortality in mother, fetus and the neonate. Journal of Medical Council of Islamic Republic of Iran (J MED COUNC ISLAMIC REPUB IRAN) 2005;23(3):319.
  121. Gravas S, Tzortzis V Rountas C Melekos MD. Extracorporeal shock-wave lithotripsy and garlic consumption: a lesson to learn. Urol Res. 2010;38(1):61-63. PubMed
  122. Sunter WH. Warfarin and garlic. Pharm J 1991;246:722.
  123. Jeyaraj S, Shivaji G, and Jeyaraj SD. Effect of a combined supplementation of fish oil (MEGA-3) with garlic pearls on the serum lipid profile, blood pressure and body mass index of hypercholesterolemic subjects. Heart 2000;83(suppl 2):A4.
  124. Ashraf R, Khan RA, Ashraf I, Qureshi AA. Effects of Allium sativum (garlic) on systolic and diastolic blood pressure in patients with essential hypertension. Pak J Pharm Sci 2013;26(5):859-63.
  125. Duncan A, Mills J. An unusual case of HIV virologic failure during treatment with boosted atazanavir. AIDS 2013;27:1361-2. PubMed
  126. Ergul B, Cakal B. Dysphagia caused by garlic induced esophagitis. Clin Res Hepatol Gastroenterol 2012;36(6):e134. PubMed
  127. Karabacak E, Aydin E, Kutlu A, Dogan B. An unusual garlic burn occurring on an unexpected area. BMJ Case Rep 2014. PubMed
  128. Ma S, Yin J. Anaphylaxis induced by ingestion of raw garlic. Foodborne Pathog Dis 2012;9(8):773-5. PubMed
  129. Mane SK, Jordan PA, Bahna SL. Eosinophilic esophagitis to unsuspected rare food allergen. Ann Allergy Asthma Immunol 2013;111(1):64-5. PubMed
  130. Ried K, Frank OR, Stocks NP. Aged garlic extract reduces blood pressure in hypertensives: a dose-response trial. Eur J Clin Nutr 2013;67(1):64-70. PubMed
  131. Roussos AP, Hirsch AR. Alliaceous migraines. Headache 2014;54(2):378-82. PubMed
  132. Watson CJ, Grando D, Fairley CK, et al. The effects of oral garlic on vaginal candida colony counts: a randomised placebo controlled double-blind trial. BJOG 2014;121(4):498-506. PubMed
  133. Xu S, Heller M, Wu PA, Nambudri VE. Chemical burn caused by topical application of garlic under occlusion. Dermatol Online J 2014;20(1):21261. DOI
  134. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  135. Gallicano K, Foster B, Choudhri S. Effect of short-term administration of garlic supplements on single-dose ritonavir pharmacokinetics in healthy volunteers. Br J Clin Pharmacol. 2003;55(2):199-202. PubMed
  136. Hou LQ, Liu YH, Zhang YY. Garlic intake lowers fasting blood glucose: meta-analysis of randomized controlled trials. Asia Pac J Clin Nutr. 2015;24(4):575-82.
  137. Oberle M, Wachs T, Brisson P. Garlic burn to the face. J Spec Oper Med. Winter 2016;16(4):80-81. PubMed
  138. Ried K. Garlic lowers blood pressure in hypertensive individuals, regulates serum cholesterol, and stimulates immunity: An updated meta-analysis and review. J Nutr. 2016;146(2):389S-396S. PubMed
  139. Shaikh SA, Tischer S, Choi EK, Fontana RJ. Good for the lung but bad for the liver? Garlic-induced hepatotoxicity following liver transplantation. J Clin Pharm Ther. 2017;42(5):646-648. PubMed
  140. Suzuki Y, Saito J, Misa K, Fukuhara N, Fukuhara A, Munakata M. A case of black garlic-induced pneumonia as an adverse reaction. Allergol Int. 2016;65(3):353-5. PubMed
  141. Treudler R, Reuter A, Engin AM, Simon JC. A case of anaphylaxis after garlic ingestion: Is alliinase the only culprit allergen? J Investig Allergol Clin Immunol. 2015;25(5):374-5.
  142. Woodbury A, Sniecinski R. Garlic-induced surgical bleeding: How much is too much? A Case Rep. 2016;7(12):266-269. PubMed
  143. Yagami A, Suzuki K, Sano A, et al. Immediate allergy due to raw garlic (Allium sativum L.). J Dermatol. 2015;42(10):1026-7.
  144. Gandomkar H, Mahmoodzadeh H, Tavakoli H, Fazeli M, Rezaei J. Garlic-induced esophageal perforation: A case series. Asian J Surg. 2020;43(6):696-697. PubMed
  145. Dev T, Bharti P, Patel U, Bhari N. Chronic paronychia and nail dystrophy: an atypical presentation of allergic contact dermatitis to garlic. Int J Dermatol 2021 Feb 11. doi: 10.1111/ijd.15430. PubMed
  146. Jafari F, Tabarrai M, Abbassian A, Jafari F, Ayati MH. Effect of Garlic (Allium sativum) Supplementation on Premenstrual Disorders: A Randomized, Double-Blind, Placebo-Controlled Trial. Evid Based Complement Alternat Med 2021;2021:9965064. PubMed
  147. Tomo S, Santos IDS, Cruz TMD, Miyahara GI, Simonato LE. Garlic burn trauma of the oral mucosa in a patient with trigeminal neuralgia: A case report. Dent Traumatol 2022. PubMed
  148. Wasef AK, Wahdan SA, Saeed NM, El-Demerdash E. Effects of aged garlic and ginkgo biloba extracts on the pharmacokinetics of sofosbuvir in rats. Biopharm Drug Dispos. 2022;43(4):152-62. PubMed
  149. Sangouni AA, Alizadeh M, Jamalzehi A, Hosseinzadeh M, Parastouei K. Garlic supplementation improves intestinal transit time, lipid accumulation product and cardiometabolic indices in subjects with metabolic syndrome: A randomized controlled trial. Phytoth PubMed
  150. Taghavi MR, Tavanaei Tamanaei T, Oghazian MB, et al. Effectiveness of fortified garlic extract oral capsules as adjuvant therapy in hospitalized patients with coronavirus disease 2019: A triple-blind randomized controlled clinical trial. Curr Ther Res Cli PubMed
  151. Jamaluddin J, Jamil SN. An unexpected reaction to topical garlic medicament - A case report of irritant contact dermatitis successfully managed in primary care. Cureus 2023;15(1):e33657. PubMed
  152. Nair A, Abdelqader B, Sureshkumar S, Katmawai-Sabbagh S. Hematuria and dietary supplements - A case report on pronounced bleeding following a minimally invasive urological intervention in a patient on long term garlic supplements. Urol Case Rep 2023;50:10 PubMed
  153. Zhao X, Cheng T, Xia H, Yang Y, Wang S. Effects of Garlic on Glucose Parameters and Lipid Profile: A Systematic Review and Meta-Analysis on Randomized Controlled Trials. Nutrients 2024;16(11):1692. PubMed
  154. Bhat GS, Shastry A. Prospective, randomized, placebo-controlled, two-arm study to evaluate the efficacy of coadministration of garlic as a hydrogen sulfide donor and tadalafil in patients with erectile dysfunction not responding to tadalafil alone - A pil

See these in context on the Garlic 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 →

Mullein 2 references
  1. Castro AI, Carmona JB, Gonzales FG, Nestar OB. Occupational airborne dermatitis from gordolobo (Verbascum densiflorum). Contact Dermatitis 2006;55(5):301.
  2. Flores Echaiz C, Al Ali A, Cao AQ, Sasseville D. Simultaneous contact dermatitis caused by Asteraceae and Verbascum thapsus. Contact Dermatitis 2017;76(5):316-8.

See these in context on the Mullein monograph →

Stinging Nettle 23 references
  1. Monographs on the medicinal uses of plant drugs. Exeter, UK: European Scientific Co-op Phytother, 1997.
  2. Newall CA, Anderson LA, Philpson JD. Herbal Medicine: A Guide for Healthcare Professionals. London, UK: The Pharmaceutical Press, 1996.
  3. The Review of Natural Products by Facts and Comparisons. St. Louis, MO: Wolters Kluwer Co., 1999.
  4. 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.
  5. Leung AY, Foster S. Encyclopedia of Common Natural Ingredients Used in Food, Drugs and Cosmetics. 2nd ed. New York, NY: John Wiley & Sons, 1996.
  6. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  7. Mittman P. Randomized, double-blind study of freeze-dried Urtica dioica in the treatment of allergic rhinitis. Planta Med 1990;56:44-7.
  8. Vontobel HP, Herzog R, Rutishauser G, Kres H. [Results of a double-blind study on the effectiveness of ERU (extractum radicis Urticae) capsules in conservative treatment of benign prostatic hyperplasia]. (Abstract). Urologe A 1985;24:49-51.
  9. Randall C, Randall H, Dobbs F, et al. Randomized controlled trial of nettle sting for treatment of base-of-thumb pain. J R Soc Med 2000;93:305-9. PubMed
  10. Caliskaner Z, Karaayvaz M, Ozturk S. Misuse of a herb: stinging nettle (Urtica urens) induced severe tongue oedema. Complement Ther Med 2004;12:57-8. PubMed
  11. Krzeski, T., Kazon, M., Borkowski, A., Witeska, A., and Kuczera, J. Combined extracts of Urtica dioica and Pygeum africanum in the treatment of benign prostatic hyperplasia: double-blind comparison of two doses. Clin Ther 1993;15(6):1011-1020.
  12. Randall, C., Meethan, K., Randall, H., and Dobbs, F. Nettle sting of Urtica dioica for joint pain--an exploratory study of this complementary therapy. Complement Ther Med 1999;7(3):126-131. PubMed
  13. Tahri, A., Yamani, S., Legssyer, A., Aziz, M., Mekhfi, H., Bnouham, M., and Ziyyat, A. Acute diuretic, natriuretic and hypotensive effects of a continuous perfusion of aqueous extract of Urtica dioica in the rat. J Ethnopharmacol 2000;73(1-2):95-100. PubMed
  14. Sahin, M., Yilmaz, H., Gursoy, A., Demirel, A. N., Tutuncu, N. B., and Guvener, N. D. Gynaecomastia in a man and hyperoestrogenism in a woman due to ingestion of nettle (Urtica dioica). N.Z.Med.J. 2007;120(1265):U2803.
  15. Randall, C., Dickens, A., White, A., Sanders, H., Fox, M., and Campbell, J. Nettle sting for chronic knee pain: a randomised controlled pilot study. Complement Ther.Med. 2008;16(2):66-72. PubMed
  16. Rayburn, K., Fleischbein, E., Song, J., Allen, B., Kundert, M., Leiter, C., and Bush, T. Stinging nettle cream for osteoarthritis. Altern.Ther.Health Med. 2009;15(4):60-61.
  17. Oliver, F., Amon, E. U., Breathnach, A., Francis, D. M., Sarathchandra, P., Black, A. K., and Greaves, M. W. Contact urticaria due to the common stinging nettle (Urtica dioica)-- histological, ultrastructural and pharmacological studies. Clin Exp Dermato PubMed
  18. Kulze, A. and Greaves, M. Contact urticaria caused by stinging nettles. Br.J Dermatol. 1988;119(2):269-270. PubMed
  19. Patten G. Medicinal plant review: Urtica. Aust J Med Herbalism 1993;5(1):5-13.
  20. Maor D, Little M. Skin contact with a stinging tree requiring intensive care unit admission. Contact Dermatitis. 2017 Nov;77(5):335-37. PubMed
  21. Easton L, Vaid S, Nagel AK, Venci JV, Fortuna RJ. Stinging Nettle (Urtica dioica): An Unusual Case of Galactorrhea. Am J Case Rep 2021;22:e933999. PubMed
  22. Niazi B, Ahmed K, Ahmed M, Ali S, Song K, Elias S. Drug-Induced Liver Injury from Herbal Liver Detoxification Tea. Case Rep Gastroenterol 2022;16(3):612-617. PubMed
  23. Nnamani I, Tolu-Akinnawo O, Dufera RR, Akintunde A, Maliakkal B. Tinospora cordifolia (Guduchi/Giloy)-Induced Liver Injury: A Case Review. Cureus 2023;15(5):e39793. PubMed

See these in context on the Stinging Nettle monograph →

Chickweed 4 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. Jovanovic M, Mimica-Dukic N, Poljacki M, Boza P. Erythema multiforme due to contact with weeds: a recurrence after patch testing. Contact Dermatitis 2003;48:17-25. PubMed
  3. Jovanovic, M., Poljacki, M., Mimica-Dukic, N., Boza, P., Vujanovic, Lj, Duran, V., and Stojanovic, S. Sesquiterpene lactone mix patch testing supplemented with dandelion extract in patients with allergic contact dermatitis, atopic dermatitis and non-alle
  4. Poljacki, M., Jovanovic, M., Boza, P., Mimica-Dukic, N., Petrovic, A., and Novovic, Z. [Is Vojvodina a risk area for contact weed allergies?]. Med Pregl. 2005;58(3-4):123-126. PubMed

See these in context on the Chickweed 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