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 9, 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.

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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.

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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

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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.

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
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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.

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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.
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  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
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  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
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  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
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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 →

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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.

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