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

Quercetin Zinc+ Ingredients & Drug Interactions

by DEVA

Quercetin Zinc+ label
See full label image
Tablet Or Pill Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 23, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Quercetin Zinc+ 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

Quercetin Zinc+ is a dietary supplement by DEVA with 6 active ingredients. Its ingredients are commonly taken for preventing or treating copper deficiency, supporting red blood cell formation, bone and connective tissue health.Based on those ingredients, 1,348 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Quercetin, Echinacea purpurea root extract, Oregano Leaf Extract. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Quercetin Zinc+ by DEVA

Ask about any prescription or over-the-counter medication and we check it for interactions with Quercetin Zinc+ by DEVA — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Quercetin Zinc+ by DEVA

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

Full disclosure
Ingredient Transparency · database check
Full

Every active ingredient lists its own amount on the label.

Why this rating?
  • The label discloses an exact amount for 6 of its 6 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

DEVA Quercetin Zinc+ contains 6 active ingredients: copper, quercetin (a plant-derived antioxidant flavonoid), elderberry fruit extract, oregano leaf extract, echinacea purpurea root extract, and zinc. Copper supports immune function and helps form connective tissue; quercetin is a bioflavonoid thought to have anti-inflammatory properties; elderberry is used traditionally for immune support; oregano leaf is an herbal extract; echinacea root is another immune-supporting herb; and zinc is an essential mineral involved in immune response, wound healing, and protein synthesis.

The tablet also contains inactive ingredients—cellulose, stearic acid, croscarmellose sodium, magnesium stearate, silica, hypromellose, and glycerin—which serve as binders, fillers, and stabilizers.

Does it work?

Strong evidence
Evidence for Intended Use · database check
By FDA rules, dietary supplements can’t claim to treat, cure, or prevent disease — so labels speak in careful marketing language. We discern each product’s intended use from its name, label claims, and label statements, then grade the clinical evidence for that use. How these ratings are computed

This product doesn't appear to be marketed for a specific use, so we graded its ingredients' overall clinical evidence instead.

Strong

Strong clinical evidence supports its ingredients for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredients' overall clinical evidence instead.
  • On file: Zinc deficiency — rated "Effective" (Zinc) (Natural Medicines).
  • On file: Copper deficiency — rated "Likely Effective" (Copper) (Natural Medicines).
  • On file: Wilson disease — rated "Likely Effective" (Zinc) (Natural Medicines).
  • On file: Acne — rated "Possibly Effective" (Zinc) (Natural Medicines).
  • On file: Acrodermatitis enteropathica — rated "Possibly Effective" (Zinc) (Natural Medicines).

The evidence for most uses in this product is incomplete or insufficient. Zinc is effective for zinc deficiency and likely effective for Wilson disease, and is possibly effective for acne and age-related macular degeneration.

Copper is likely effective for copper deficiency but possibly ineffective for Alzheimer disease. Quercetin and echinacea have insufficient reliable evidence for the conditions they're marketed for—including hay fever, asthma, cognitive decline, and athletic performance.

Elderberry and oregano likewise lack solid evidence for their traditional uses such as respiratory infection, fatigue, or asthma. In short, this is primarily a supplement whose individual ingredients have not been proven effective for most common claims.

The evidence, ingredient by ingredient Copper Quercetin Elderberry Oregano Echinacea Zinc

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 6 of the 6 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 6 of 6.
  • General safety write-ups exist for 6 of 6.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Overall, the ingredients in normal doses are generally well tolerated, though some carry cautions. Copper is safe in standard supplement amounts but excess can be toxic; it's needed in pregnancy but only in recommended amounts.

Quercetin is generally well tolerated at food and typical supplement doses, but high-dose and long-term safety are not well studied. Zinc is safe at doses below 40 mg daily for adults; higher doses may increase the risk of copper deficiency over time.

Echinacea is usually well tolerated short-term but may trigger allergic reactions in people sensitive to ragweed. Elderberry made from cooked ripe fruit is generally well tolerated, though raw berries and other plant parts contain cyanogenic glycosides that can cause nausea and severe diarrhea (cooking destroys the toxin).

Oregano at food amounts is safe; concentrated oils are less studied. Common mild side effects include nausea, diarrhea, abdominal upset, and rashes.

Rare serious effects—hepatitis, severe allergic reactions, and anaphylaxis—have been reported with echinacea and elderberry.

Side effects, ingredient by ingredient Copper Quercetin Elderberry Oregano Echinacea Zinc

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?
  • 6 of the 6 matched ingredients can interact with medications — Quercetin, Elderberry, Oregano, Copper, Echinacea, among others.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; diabetes medications.
  • For scale: 1,349 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 DEVA Quercetin Zinc+, check with your doctor or pharmacist if you take blood thinners (warfarin), blood pressure medications (losartan), cholesterol drugs (pravastatin), diabetes medications, immunosuppressants, antibiotics (especially quinolones, tetracyclines, cephalexin, or penicillamine), HIV protease inhibitors or integrase inhibitors, cancer drugs, sedatives (midazolam), or any CYP3A4 substrates. The product contains quercetin, echinacea, zinc, copper, oregano, and elderberry—each with documented interactions at Moderate and Minor severity.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.

This product combines immune-support and antioxidant ingredients with limited clinical evidence. It's best suited for people looking to fill a copper or zinc deficiency, since those uses have solid data.

If you take blood thinners, diabetes medications, antibiotics, HIV drugs, or immunosuppressants, check your specific medications against the tool on this page before adding this product—the interactions are real and could affect how your drugs work. Talk it over with your doctor or pharmacist before starting, especially if you're on any regular prescriptions.

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

Assessment coverage: 6 of 6 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Aug 23, 2023.

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 Quercetin Zinc+, straight from the product label.

Brand DEVA
Barcode (UPC) 895634000669
Net contents 90 Tablet(s)
Market status On market
Date entered into DSLD Aug 23, 2023
DSLD ID 299495
Product type Other Combinations
Supplement form Tablet Or Pill
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
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 Quercetin Zinc+ by DEVA, 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 Tablet(s)
Maximum serving Sizes:
1 Tablet(s)
Servings per container
90
UPC/BARCODE
895634000669
IngredientAmount% DV
Copper0.225 mg25%
Quercetin500 mg--
Elderberry Fruit Extract50 mg--
Oregano Leaf Extract25 mg--
Echinacea purpurea root extract25 mg--
Zinc25 mg227%

Other ingredients: Cellulose, Stearic Acid, Croscarmellose Sodium, Magnesium Stearate, Silica, Hypromellose, Glycerin

Tap any ingredient to jump to its full detail below.

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

Vegan

This product does not contain any animal products, derivatives or byproducts.

Guaranteed 100% vegan

Food sensitivity: free of yeast, soy, wheat, gluten, dairy, egg, salt, shellfish, sugar, animal products or derivatives.

Seals/Symbols

Vegan

General Statements

This product is registered with the Vegan Society.

Formula

Quercetin is a flavonoid pigment that is present in many fruits and vegetables. Zinc is an essential mineral our body needs for health and proper function.

Quercetin zinc + includes elderberry, echinacea & oregano extracts 500 mg Quercetin + 25 mg zinc

Storage

Store in a cool, dry place.

Precautions

Tamper evident: Do not use if imprinted seal under cap is broken.

Keep out of reach of children.

Warning: always consult your health care provider before taking dietary supplements.

FDA Disclaimer Statement

These statements have not been evaluated by the Food and Drug administration. This product is not intended to diagnose, treat, cure or prevent any disease.

FDA Statement of Identity

Dietary Supplement

Suggested/Recommended/Usage/Directions

Directions: for adults, take 1 tablet daily with food or as directed by a doctor.

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

See for yourself

Quercetin Zinc+ by DEVA label

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

Quercetin Zinc+ 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 Quercetin Zinc+ by DEVA

These are the 6 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Tablet(s) Dosage formTablet Or Pill Servings per container90 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.

Copper

Interacts with
31 drugs
0.225 mg per serving Form: Copper Amino Acid Chelate

Copper is an essential trace mineral your body needs in small amounts for making red blood cells, supporting nerves and bones, and helping enzymes wor...

Copper monograph & interactions

Quercetin

Interacts with
1,169 drugs
500 mg per serving Form: Quercetin Dihydrate

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early rese...

Quercetin monograph & interactions

Elderberry Fruit Extract

Interacts with
121 drugs
50 mg per serving Form: Sambucus nigra Fruit Extract

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu sym...

Elderberry Fruit Extract monograph & interactions

Oregano Leaf Extract

Interacts with
208 drugs
25 mg per serving

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacr...

Oregano Leaf Extract monograph & interactions

Echinacea purpurea root extract

Interacts with
816 drugs
25 mg per serving

Echinacea is a popular herb taken to help prevent or shorten the common cold, but study results are mixed and the overall benefit appears small at bes...

Echinacea purpurea root extract monograph & interactions

Zinc

Interacts with
67 drugs
25 mg per serving Form: Zinc Amino Acid Chelate, Zinc Citrate

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but suppleme...

Zinc monograph & interactions

Other (inactive) ingredients: Cellulose, Stearic Acid, Croscarmellose Sodium, Magnesium Stearate, Silica, Hypromellose, Glycerin. These complete the product’s ingredient list but are not active constituents.

Interaction report

Quercetin Zinc+ by DEVA Drug Interactions

Want to check YOUR meds against Quercetin Zinc+?

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
1,348Drugs
1,344 Moderate 4 Minor

Ingredients driving the most interactions

Quercetin 1,169
Echinacea purpurea root extract 816
Oregano Leaf Extract 208
Elderberry Fruit Extract 121
Zinc 67

Individual Drug Interactions

The ingredients in Quercetin Zinc+ interact with 1,348 drugs. Click any drug to see the details.

6 of the 6 ingredients in Quercetin Zinc+ interact with drugs. Each result below shows which ingredient is responsible. Quercetin Echinacea purpurea root extract Oregano Leaf Extract Elderberry Fruit Extract Zinc Copper

Each ingredient & the kinds of drugs it affects

For each ingredient in Quercetin Zinc+ 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.

Quercetin21 drug types · 1,169 drugs

Antidiabetes Drugs

Theoretically, concomitant use of quercetin and antidiabetes drugs might increase the risk of hypoglycemia.

Clinical research suggests that a combination of quercetin, myricetin, and chlorogenic acid reduce levels of fasting glucose in patients with type 2 diabetes, including those already taking antidiabetes agents. The effect of quercetin alone is unknown.

Likelihood Possible Evidence B
Antihypertensive Drugs

Theoretically, taking quercetin with antihypertensive drugs might increase the risk of hypotension.

Quercetin can modestly decrease blood pressure in people with mild hypertension. Theoretically, it might have additive blood pressure lowering effects when used with antihypertensive drugs.

Likelihood Possible Evidence B
Cyclosporine (Neoral, Sandimmune)

Theoretically, concomitant use might increase the levels and adverse effects of cyclosporine.

A small study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine, possibly due to inhibition of p-glycoprotein or cytochrome P450 3A4 (CYP3A4), which metabolizes cyclosporin.

Likelihood Possible Evidence B
Cytochrome P450 2C8 (Cyp2C8) Substrates

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C8 substrates.

In vitro research shows that quercetin inhibits CYP2C8. Inhibition of paclitaxel (Taxol) metabolism via CYP2C8 has been reported in vitro. However, a small study in humans found no effect of quercetin on rosiglitazone (Avandia), which is also a CYP2C8 substrate.

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

Theoretically, concomitant use might increase the levels and adverse effects of CYP2C9 substrates.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac, a CYP2C9 substrate, increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar), a substrate of CYP2C9. Furthermore, laboratory research shows that quercetin inhibits CYP2C9.

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

Theoretically, concomitant use might increase the levels and adverse effects of CYP2D6 substrates.

In vitro research show that quercetin inhibits CYP2D6. This effect has not been reported in humans.

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

Theoretically, concomitant use might alter the effects and adverse effects of CYP3A4 substrates.
A small clinical study in healthy volunteers shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of a single dose of cyclosporine (Neoral, Sandimmune), a substrate of CYP3A4. Animal research also shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) and quetiapine (Seroquel), substrates of CYP3A4. Other laboratory research also shows that quercetin inhibits CYP3A4. However, one clinical study shows that quercetin can increase the metabolism of midazolam, a substrate of CYP3A4, and decrease serum concentrations of midazolam by about 24% in some healthy individuals, suggesting possible induction of CYP3A4.

Likelihood Possible Evidence D
Diclofenac (Voltaren, Others)

Theoretically, concomitant use might increase the levels and adverse effects of diclofenac.

A small clinical study in healthy volunteers shows that taking quercetin 500 mg twice daily for 10 days prior to taking diclofenac increases diclofenac plasma levels by 75% and prolongs the half-life by 32.5%. This is thought to be due to inhibition of CYP2C9 by quercetin.

Likelihood Probable Evidence B
Losartan (Cozaar)

Theoretically, concomitant use might increase the effects and adverse effects of losartan and decrease the effects of its active metabolite.

Animal research shows that pretreatment with quercetin increases plasma levels and prolongs the half-life of losartan (Cozaar) while decreasing plasma levels of losartan's active metabolite. This metabolite, which is around 10-fold more potent than losartan, is the result of cytochrome P450 (CYP) 2C9- and CYP3A4-mediated transformation of losartan. Additionally, in vitro research shows that quercetin may inhibit P-glycoprotein-mediated efflux of losartan from the intestines, resulting in increased absorption of losartan. These results suggest that concomitant use of quercetin and losartan might increase systemic exposure to losartan while also decreasing plasma concentrations of losartan's active and more potent metabolite.

Likelihood Possible Evidence D
Midazolam (Versed)

Theoretically, concomitant use might decrease the levels and effects of midazolam.

A small clinical study in healthy volunteers shows that quercetin can increase the metabolism of midazolam, with a decrease in AUC of about 24%.

Likelihood Possible Evidence B
Mitoxantrone

Theoretically, quercetin might increase the effects and adverse effects of mitoxantrone.
In vitro research shows that quercetin increases the intracellular accumulation and cytotoxicity of mitoxantrone, possibly through inhibition of breast cancer resistance protein (BCRP), of which mitoxantrone is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 1 (Oat1) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT1 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT1, with half-maximal inhibitory concentration (IC50) values less than 10 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion Transporter 3 (Oat3) Substrates

Theoretically, concomitant use might increase the effects and adverse effects of OAT3 substrates.

In vitro research shows that quercetin is a strong non-competitive inhibitor of OAT3, with half-maximal inhibitory concentration (IC50) values as low as 0.75 mcM. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Organic Anion-Transporting Polypeptide Substrates (Oatp)

Theoretically, concomitant use might increase the effects and adverse effects of OATP substrates.

In vitro evidence shows that quercetin can inhibit organic anion-transporting peptide (OATP) 1B1-mediated uptake of estrone-3-sulfate and pravastatin. Furthermore, clinical research in healthy males shows that intake of quercetin along with pravastatin increases the AUC of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
P-Glycoprotein Substrates

Theoretically, concomitant use might alter the effects and adverse effects of P-glycoprotein substrates.

There is preliminary evidence that quercetin inhibits the gastrointestinal P-glycoprotein efflux pump, which might increase the bioavailability and serum levels of drugs transported by the pump. A small study in healthy volunteers reported that pretreatment with quercetin increased bioavailability and plasma levels after a single dose of cyclosporine (Neoral, Sandimmune). Also, two small studies have shown that quercetin might decrease the absorption of talinolol, a substrate transported by the gastrointestinal P-glycoprotein efflux pump. However, in another small study, several days of quercetin treatment did not significantly affect the pharmacokinetics of saquinavir (Invirase). The reason for these discrepancies is not entirely clear. Until more is known, use quercetin cautiously in combination with P-glycoprotein substrates.

Likelihood Possible Evidence B
Pravastatin (Pravachol)

Theoretically, concomitant use might increase the effects and adverse effects of pravastatin.
In vitro evidence shows that quercetin can inhibit OATP 1B1-mediated uptake of pravastatin. Also, preliminary clinical research in healthy males shows that intake of quercetin along with pravastatin increases the maximum concentration of pravastatin by 24%, prolongs its half-life by 14%, and decreases its apparent clearance by 18%, suggesting that quercetin modestly inhibits the uptake of pravastatin in hepatic cells.

Likelihood Possible Evidence B
Prazosin (Minipress)

Theoretically, quercetin might increase the effects and adverse effects of prazosin.
In vitro research shows that quercetin inhibits the transcellular efflux of prazosin, possibly through inhibition of breast cancer resistance protein (BCRP), of which prazosin is a substrate. BCRP is an ATP-binding cassette efflux transporter in the intestines, kidneys, and liver. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Quetiapine (Seroquel)

Theoretically, concomitant use might increase the effects and adverse effects of quetiapine.
Animal research shows that pretreatment with quercetin can increase plasma levels of quetiapine and prolong its clearance, possibly due to inhibition of cytochrome P450 3A4 (CYP3A4) by quercetin. Additionally, the brain-to-plasma ratio of quetiapine concentrations increased, possibly due to inhibition of P-glycoprotein at the blood-brain barrier. This interaction has not been reported in humans.

Likelihood Possible Evidence D
Quinolone Antibiotics

Theoretically, concomitant use might inhibit the effects of quinolone antibiotics.
In vitro, quercetin binds to the DNA gyrase site on bacteria, which may interfere with the activity of quinolone antibiotics.

Likelihood Possible Evidence B
Sulfasalazine (Azulfidine)

Theoretically, quercetin might increase the effects and adverse effects of sulfasalazine.
Animal research shows that quercetin increases the maximum serum concentration (Cmax) and area under the curve (AUC) of sulfasalazine, possibly through inhibition of breast cancer resistance protein (BCRP), of which sulfasalazine is a substrate. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, quercetin may increase the risk of bleeding if used with warfarin.
Animal and in vitro studies show that quercetin might increase serum levels of warfarin. Quercetin and warfarin have the same human serum albumin (HSA) binding site, and in vitro research shows that quercetin has stronger affinity for the HSA binding site and can theoretically displace warfarin, causing higher serum levels of warfarin. Animal research shows that taking quercetin for 2 weeks before initiating warfarin increases the maximum serum level of warfarin by 30%, the half-life by 10%, and the overall exposure by 63% when compared with control. Concomitant administration of quercetin and warfarin, without quercetin pre-treatment, also increased these measures, but to a lesser degree. Researchers theorize that inhibition of CYP3A4 by quercetin may explain these effects. So far, this interaction has not been reported in humans.

Likelihood Possible Evidence D
Quercetin full monograph & interactions

Echinacea purpurea root extract12 drug types · 816 drugs

Caffeine

Echinacea can increase plasma levels of caffeine by inhibiting its metabolism.
Echinacea seems to increase plasma concentrations of caffeine by around 30%. This is likely due to inhibition of cytochrome P450 1A2 (CYP1A2) by echinacea.

Likelihood Probable Evidence B
Cytochrome P450 1A2 (Cyp1A2) Substrates

Echinacea might inhibit the metabolism of CYP1A2 and increase plasma levels of some drugs.
Echinacea appears to inhibit CYP1A2 enzymes in humans. Additionally, echinacea seems to increase plasma concentrations of caffeine, a CYP1A2 substrate, by around 30%. Theoretically, echinacea might increase levels of other drugs metabolized by CYP1A2.

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

Echinacea may induce hepatic CYP3A4 and inhibit intestinal CYP3A4. This may increase or decrease levels of drugs metabolized by CYP3A4.
Several clinical trials have shown that taking echinacea for up to one month does not significantly affect the metabolism of various CYP3A4 substrates, including midazolam, docetaxel, etravirine, lopinavir-ritonavir, and darunavir-ritonavir. However, other clinical research shows that echinacea may increase the clearance of midazolam, suggesting that echinacea might induce CYP3A4. The discrepancy is thought to be due to differing effects of echinacea on intestinal versus hepatic CYP3A4 enzymes. Echinacea appears to induce hepatic CYP3A4 but inhibit intestinal CYP3A4. In some cases, these effects might cancel each other out, but in others, drug levels may be increased or decreased depending on the level of effect at hepatic and intestinal sites. The effect of echinacea on CYP3A4 activity may differ depending on the CYP3A4 substrate.

Likelihood Possible Evidence B
Etoposide (Vepesid)

Echinacea may increase levels of etoposide.
In one report, concomitant use of etoposide and echinacea was associated with more severe thrombocytopenia than the use of etoposide alone, suggesting inhibition of etoposide metabolism. Etoposide is a cytochrome P450 3A4 (CYP3A4) substrate. Echinacea has variable effects on CYP3A4, but some studies have reported inhibition of the enzyme.

Likelihood Possible Evidence D
Immunosuppressants

Echinacea has immunostimulant activity which may interfere with immunosuppressant therapy.
Theoretically, echinacea may interfere with immunosuppressant therapy because of its immunostimulant activity.

Likelihood Possible Evidence B
Darunavir (Prezista)

Theoretically, echinacea may interfere with the metabolism of darunavir; however, a small clinical study found no effect.
Darunavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but administration of an E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg four times daily for 14 days did not affect darunavir/ritonavir pharmacokinetics in 15 HIV-infected patients.

Likelihood Unlikely Evidence B
Dayquil Severe

Echinacea is reported to have varying effects on a number of Cytochrome P450 metabolizing enzymes in the liver, including CYP1A2 and CYP3A4, which play a role in acetaminophen and dextromethorphan metabolism (both contained in DayQuil Severe), respectively. Studies have reported both enzyme inhibition and induction, making it difficult to predict clinically significant drug interactions with reliability. Specific drug interaction studies reporting definitive results are rare, and potential drug interactions involving echinacea should likely be taken on a case-by-case basis. Based on what we know about how acetaminophen and dextromethorphan are metabolized, the risk of a clinically significant interaction between echinacea and DayQuil Severe is low.

Likelihood Unlikely Evidence A
Docetaxel (Taxotere)

Theoretically, echinacea may interfere with the metabolism of docetaxel; however, a small clinical study found no effect.
Docetaxel is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea whole plant extract (Echinaforce, A. Vogel Biopharma AG) 20 drops three times daily for 2 weeks did not alter the pharmacokinetics of docetaxel in one clinical study.

Likelihood Unlikely Evidence B
Etravirine (Intelence)

Theoretically, echinacea may interfere with the metabolism of etravirine; however, a small clinical study found no effect.
Etravirine is metabolized by cytochrome P450 3A4 (CYP3A4). Echinacea has variable effects on CYP3A4, but taking E. purpurea root extract (Arkocapsulas Echinacea, Arkopharma) 500 mg three times daily for 14 days did not alter the pharmacokinetics of etravirine in HIV-infected patients.

Likelihood Unlikely Evidence B
Lopinavir/Ritonavir (Kaletra)

Theoretically, echinacea may interfere with the metabolism of lopinavir; however, a small clinical study found no effect.
Lopinavir is metabolized by cytochrome P450 3A4 (CYP3A4) and is administered with the CYP3A4 inhibitor ritonavir to increase its plasma concentrations. Echinacea has variable effects on CYP3A4, but taking E. purpurea (Echinamide, Natural Factors Nutritional Products, Inc.) 500 mg three times daily for 14 days did not alter the pharmacokinetics of lopinavir/ritonavir in healthy volunteers.

Likelihood Unlikely Evidence B
Midazolam (Versed)

Theoretically, echinacea may increase the metabolism of intravenous midazolam.
Echinacea induces hepatic CYP3A4 and might decrease plasma levels of midazolam by about 20%, reducing the effectiveness of intravenous midazolam. Echinacea also appears to inhibit intestinal CYP3A4, which could theoretically increase the bioavailability of oral midazolam. This may cancel out the decrease in availability caused by induction of hepatic CYP3A4, such that overall plasma levels after oral administration of midazolam are not affected by echinacea.

Likelihood Possible Evidence B
Warfarin (Coumadin)

Echinacea seems to increase the clearance of warfarin, although the effect may not be clinically significant.
Preliminary clinical research in healthy male volunteers suggests that taking echinacea increases the clearance of the active S-isomer of warfarin after a single dose of warfarin, but there was not a clinically significant effect on the INR.

Likelihood Possible Evidence B
Echinacea purpurea root extract full monograph & interactions

Oregano Leaf Extract2 drug types · 208 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, oregano might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
In vitro research shows that aristolochic acid isolated from oregano leaves has antithrombin activity. It has also been reported that oregano oil inhibits arachidonic acid-induced, and ADP-induced, platelet aggregation.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, oregano might increase the risk for hypoglycemia when taken with antidiabetes drugs.
In vitro and animal research shows that oregano extracts might lower blood glucose levels.

Likelihood Possible Evidence D
Oregano Leaf Extract full monograph & interactions

Elderberry Fruit Extract2 drug types · 121 drugs

Immunosuppressants

Theoretically, elderberry might interfere with immunosuppressant therapy due to its immunostimulant activity.
Elderberry has immunostimulant activity, increasing the production of cytokines, including interleukin and tumor necrosis factor.

Likelihood Possible Evidence B
Pazopanib (Votrient)

Theoretically, elderberry might interact with pazopanib, potentially increasing the risk of adverse effects.
In one case, a 65-year-old patient taking pazopanib for 4 weeks for soft-tissue sarcoma developed severe nausea, loose stools, and elevated alanine transaminase and aspartate transaminase levels and was diagnosed with grade 3 liver injury. The patient reported taking elderberry supplements for 2 years, dose unspecified, and was also taking a multivitamin and a calcium supplement. The patient's symptoms and liver enzyme levels improved upon discontinuation of pazopanib and all supplements. Pazopanib treatment was re-initiated, at a lower dose, with no further evidence of liver injury. It was unclear in this case report if the elderberry supplements were derived from the berry, the flower, or the combination.

Likelihood Possible Evidence D
Elderberry Fruit Extract full monograph & interactions

Zinc10 drug types · 67 drugs

Bictegravir/Emtricitabine/Tenofovir Alafenamide (Biktarvy)

Theoretically, zinc might decrease levels of bictegravir/emtricitabine/tenofovir alafenamide by reducing its absorption.
Advise patients that bictegravir/emtricitabine/tenofovir alafenamide should be taken at least 2 hours before or 6 hours after zinc containing products.

Likelihood Probable Evidence D
Cephalexin (Keflex)

Zinc might decrease cephalexin levels by chelating with cephalexin in the gut and preventing its absorption.
A pharmacokinetic study shows that zinc sulfate 250 mg taken concomitantly with cephalexin 500 mg decreases peak levels of cephalexin by 31% and reduces the exposure to cephalexin by 27%. Also, taking zinc sulfate 3 hours before cephalexin decreases peak levels of cephalexin by 11% and reduces the exposure to cephalexin by 18%. By decreasing cephalexin levels, zinc might increase the risk of treatment failure. This effect does not occur when zinc is taken 3 hours after the cephalexin dose. To avoid an interaction, advise patients take zinc sulfate 3 hours after taking cephalexin.

Likelihood Probable Evidence B
Cisplatin (Platinol-Aq)

Theoretically, zinc might interfere with the therapeutic effects of cisplatin.
Animal research suggests that zinc stimulates tumor cell production of the protein metallothionein, which binds and inactivates cisplatin. It is not known whether zinc supplements or high dietary zinc intake can cause clinically significant interference with cisplatin therapy. Cisplatin might also increase zinc excretion.

Likelihood Possible Evidence D
Integrase Inhibitors

Theoretically, taking zinc along with integrase inhibitors might decrease the levels and clinical effects of these drugs.
Zinc is a divalent cation. Pharmacokinetic studies have shown that other divalent cations such as calcium and iron can decrease blood levels of the integrase inhibitor dolutegravir through chelation.

Likelihood Possible Evidence D
Penicillamine (Cuprimine, Depen)

Zinc might reduce the levels and clinical effects of penicillamine.
By forming an insoluble complex with penicillamine, zinc interferes with penicillamine absorption and activity. Zinc supplements reduce the efficacy of low-dose penicillamine (0.5-1 gram/day), but do not seem to affect higher doses (1-2.75 gram/day), provided dosing times are separated. Advise patients to take zinc and penicillamine at least 2 hours apart.

Likelihood Probable Evidence B
Quinolone Antibiotics

Zinc can decrease the levels and clinical effects of quinolones antibiotics.
Quinolones form complexes with zinc in the gastrointestinal tract, reducing absorption of both the quinolone and zinc if taken at the same time. Advise patients to take these drugs at least 2 hours before, or 4-6 hours after, zinc supplements.

Likelihood Probable Evidence B
Ritonavir (Norvir)

Zinc modestly reduces levels of ritonavir.
Clinical research shows that zinc might reduce serum ritonavir levels by chelating with ritonavir in the gut and preventing its absorption. In patients with HIV, ritonavir is taken with atazanavir to prevent the metabolism and increase the effects of atazanavir. A pharmacokinetic study shows that, in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate (Solvazinc tablets) 125 mg as a single dose or as multiple daily doses for 2 weeks reduces plasma levels of ritonavir by about 16%. However, atazanavir levels still remains high enough to prevent HIV virus replication. Therefore, the decrease in ritonavir levels is not likely to be clinically significant.

Likelihood Probable Evidence B
Tetracycline Antibiotics

Zinc might reduce levels of tetracycline antibiotics.
Tetracyclines form complexes with zinc in the gastrointestinal tract, which can reduce absorption of both the tetracycline and zinc when taken at the same time. Taking zinc sulfate 200 mg with tetracycline reduces absorption of the antibiotic by 30% to 40%. Demeclocycline and minocycline cause a similar interaction. However, doxycycline does not seem to interact significantly with zinc. Advise patients to take tetracyclines at least 2 hours before, or 4-6 hours after, zinc supplements to avoid any interactions.

Likelihood Probable Evidence B
Amiloride (Midamor)

Amiloride can modestly reduce zinc excretion and increase zinc levels.
Clinical research shows that amiloride can reduce urinary zinc excretion, especially at doses of 10 mg per day or more. This zinc-sparing effect can help to counteract zinc losses caused by thiazide diuretics, but it is unlikely to cause zinc toxicity at usual amiloride doses. The other potassium-sparing diuretics, spironolactone (Aldactone) and triamterene (Dyrenium), do not seem to have a zinc-sparing effect.

Likelihood Probable Evidence B
Atazanavir (Reyataz)

Zinc modestly reduces levels of atazanavir, although this effect does not seem to be clinically significant.
Clinical research shows that zinc might decrease serum atazanavir levels by chelating with atazanavir in the gut and preventing its absorption. Although a single dose of zinc sulfate (Solvazinc tablets) 125 mg orally does not affect atazanavir concentrations in patients being treated with atazanavir/ritonavir, co-administration of zinc sulfate 125 mg daily for 2 weeks reduces plasma levels of atazanavir by about 22% in these patients. However, despite this decrease, atazanavir levels still remain at high enough concentrations for the prevention of HIV virus replication.

Likelihood Probable Evidence B
Zinc full monograph & interactions

Copper2 drug types · 31 drugs

Penicillamine (Cuprimine, Depen)

Theoretically, taking copper with penicillamine might decrease the absorption of penicillamine; separate dosing by at least 2 hours.
Copper chelates penicillamine, which decreases its absorption and may reduce its clinical effects.

Likelihood Probable Evidence D
Contraceptive Drugs

Theoretically, taking copper with contraceptive drugs might increase the levels and toxic effects of copper.
A meta-analysis of clinical studies suggests that chronic use of oral contraceptives increases serum copper levels by a mean of 57 mcg/dL. In most people, this resulted in levels above the normal reference range for copper.

Likelihood Possible Evidence D
Copper full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Quercetin Zinc+, from the product label.

DEVA

See all DEVA products
Name
DEVA Nutrition LLC
Phone Number
(888)988-3382
Web Address
www.devanutrition.com
Pharmacist Counseling Corner

Quercetin Zinc+ by DEVA: Common Questions

Does Quercetin Zinc+ by DEVA interact with any medications?
Yes. Based on its ingredients, Quercetin Zinc+ has a known interaction with 1,348 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Quercetin Zinc+ contains 6 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.
Is it safe to take this while pregnant?
The safety picture is mixed. Copper is likely safe and needed in pregnancy, but at normal doses only. Zinc is likely safe in recommended amounts. However, quercetin is rated as possibly unsafe in supplemental doses—there isn't enough data—so you should avoid supplement amounts. Elderberry and oregano also lack enough safety data, so they're best avoided in pregnancy unless your doctor approves. Talk with your doctor or pharmacist before taking this product if you're pregnant.
What if I'm breastfeeding?
Copper and zinc are likely safe while breastfeeding at normal intake levels. Quercetin, echinacea, elderberry, and oregano, however, lack enough safety data for breastfeeding—the safety notes advise caution or avoidance. Speak with your doctor or pharmacist about whether this product is right for you while nursing.
Can this product help with hay fever or cold symptoms?
Elderberry and echinacea are traditionally used for respiratory issues and immune support, but the data on this product says there's insufficient reliable evidence that either works for hay fever, colds, or lower respiratory infections. Don't rely on this as a proven treatment for those conditions.
What are the common side effects?
Mild side effects from the ingredients include nausea, diarrhea, abdominal cramps, headache, and rashes—most dose-related and reversible. Echinacea and elderberry can rarely trigger allergic reactions or hepatitis (liver inflammation). Zinc above 40 mg daily may cause metallic taste or diarrhea. If you experience severe allergic signs, liver symptoms (jaundice, abdominal pain), or persistent side effects, stop and contact your doctor.
How much zinc and copper are in each tablet?
The product facts don't specify the exact dose of each ingredient per tablet, only that the product contains them. Check the supplement label on the bottle for the serving size and individual amounts of copper and zinc.
Can I take this long-term?
Copper and zinc are safe long-term at normal dietary and recommended supplement doses. Quercetin's long-term safety at high doses is not well studied. Echinacea is well tolerated short-term; long-term use hasn't been as thoroughly studied. Elderberry and oregano as supplements also lack long-term safety data. For extended use beyond a few weeks, speak with your doctor or pharmacist.

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

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Label information is sourced from the NIH Dietary Supplement Label Database and reflects the product version on file; always read your actual product label. This page is for education only and is not a substitute for professional medical advice. Confirm with your pharmacist or doctor before combining supplements and medications.

Quercetin Zinc+ label
Go deeper

The Full Monographs Behind Quercetin Zinc+’s Ingredients

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

Herb & supplement monograph

Copper

Interacts with 31 drugs

Copper is an essential trace mineral your body needs in small amounts for making red blood cells, supporting nerves and bones, and helping enzymes work. Most people get enough copper from fo...

Read the full Copper monograph → Herb & supplement monograph

Quercetin

Interacts with 1,169 drugs

Quercetin is a plant flavonoid with antioxidant and anti-inflammatory properties found in many common foods and sold as a supplement. While early research is interesting for allergies, blood...

Read the full Quercetin monograph → Herb & supplement monograph

Elderberry

Interacts with 121 drugs

Elderberry is a popular herbal supplement, mainly taken to help with colds and flu. Some small studies suggest it may modestly shorten cold or flu symptoms, but the evidence is limited and n...

Read the full Elderberry monograph → Herb & supplement monograph

Oregano

Interacts with 208 drugs

Oregano is a common Mediterranean cooking herb that is also sold as a concentrated oil or supplement, often standardized for a compound called carvacrol. While lab studies suggest it may hav...

Read the full Oregano monograph → Herb & supplement monograph

Echinacea

Interacts with 816 drugs

Echinacea is a popular herb taken to help prevent or shorten the common cold, but study results are mixed and the overall benefit appears small at best. It is generally well tolerated for sh...

Read the full Echinacea monograph → Herb & supplement monograph

Zinc

Interacts with 67 drugs

Zinc is an essential mineral that your body needs for immune function, wound healing, taste, and smell. Most people get enough from food, but supplements can help correct or prevent a defici...

Read the full Zinc monograph →
Sources

Sources & How We Checked

Quercetin Zinc+'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 194 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.

Copper 11 references
  1. Murry JJ, Healy MD. Drug-mineral interactions: a new responsibility for the hospital dietician. J Am Diet Assoc 1991;91:66-73.
  2. Campbell IA, Elmes PC. Ethambutol and the eye: zinc and copper (letter). Lancet 1975;2:711. DOI
  3. Segal S, Kaminski S. Drug-nutrient interactions. American Druggist 1996 Jul;42-8.
  4. Kozak SF, Inderlied CB, Hsu HY, et al. The role of copper on ethambutol's antimicrobial action and implications for ethambutol-induced optic neuropathy. Diag Microbiol Infect Dis 1998;30:83-7. PubMed
  5. Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Vitamin A, Vitamin K, Arsenic, Boron, Chromium, Copper, Iodine, Iron, Manganese, Molybdenum, Nickel, Silicon, Vanadium, and Zinc. Washington, DC: National Academy Press, 2002.
  6. Cantilena LR, Klaassen CD. The effect of chelating agents on the excretion of endogenous metals. Toxicol Appl Pharmacol 1982;63:344-50.
  7. Babic Z, Tariba B, Kovacic J, Pizent A, Varnai VM, Macan J. Relevance of serum copper elevation induced by oral contraceptives: a meta-analysis. Contraception. 2013 Jun;87(6):790-800. PubMed
  8. Qui Q, Zhang F, Zhu W, Wu J, Liang M. Copper in diabetes mellitus: a meta-analysis and systematic review of plasma and serum studies. Biol Trace Elem Res 2017;177(1):53-63.
  9. Walker-Smith PK, Keith DJ, Kennedy CT, Sansom JE. Allergic contact dermatitis caused by copper. Contact Dermatitis 2016;75(3):186-7. PubMed
  10. Gallentine A. Third-degree burn on the neuropathic lower extremity in a patient with diabetes while wearing a copper-containing compression sock: a case report. Wound Manag Prev 2021;67(12):26-29. DOI
  11. Chung KJ, Chin YM, Wong MS, Sanmugam A, Singaravel S, Nah SA. Effectiveness of table salt versus copper sulphate in treating umbilical granuloma: A pilot randomized controlled trial. J Pediatr Surg 2022;57(2):261-265. PubMed

See these in context on the Copper monograph →

Quercetin 26 references
  1. Shoskes DA, Zeitlin SI, Shahed A, Rajfer J. Quercetin in men with category III chronic prostatitis: A preliminary prospective, double-blind, placebo-controlled trial. Urol 1999;54:960-3. PubMed
  2. Starvic B. Quercetin in our diet: from potent mutagen to probable anticarcinogen. Clin Biochem 1994;27:245-8. PubMed
  3. Ferry DR, Smith A, Malkhandi J, et al. Phase I clinical trial of the flavonoid quercetin: Pharmacokinetics and evidence for in vivo tyrosine kinase inhibition. Clin Cancer Res 1996;2:659-67..
  4. Obach RS. Inhibition of human cytochrome P450 enzymes by constituents of St. John's wort, an herbal preparation used in the treatment of depression. J Pharmacol Exp Ther 2000;294:88-95. DOI
  5. Edwards RL, Lyon T, Litwin SE, et al. Quercetin reduces blood pressure in hypertensive subjects. J Nutr 2007;137:2405-11.
  6. Kim KA, Park PW, Kim HK, et al. Effect of quercetin on the pharmacokinetics of rosiglitazone, a CYP2C8 substrate, in healthy subjects. J Clin Pharmacol 2005;45:941-6. PubMed
  7. DiCenzo R, Frerichs V, Larppanichpoonphol P, et al. Effect of quercetin on the plasma and intracellular concentrations of saquinavir in healthy adults. Pharmacotherapy 2006;26:1255-61. PubMed
  8. Choi JS, Choi BC, Choi KE. Effect of quercetin on the pharmacokinetics of oral cyclosporine. Am J Health Syst Pharm 2004;61:2406-9. PubMed
  9. Choi JS, Jo BW, Kim YC. Enhanced paclitaxel bioavailability after oral administration of paclitaxel or prodrug to rats pretreated with quercetin. Eur J Pharm Biopharm 2004;57:313-8. PubMed
  10. Vaclavikova R, Horsky S, Simek P, Gut I. Paclitaxel metabolism in rat and human liver microsomes is inhibited by phenolic antioxidants. Naunyn Schmiedebergs Arch Pharmacol 2003;368:200-9. PubMed
  11. Di Bari L, Ripoli S, Pradhan S, Salvadori P. Interactions between quercetin and warfarin for albumin binding: A new eye on food/drug interference. Chirality 2010;22:593-6. PubMed
  12. Lamson, D. W. and Brignall, M. S. Antioxidants and cancer, part 3: quercetin. Altern.Med.Rev. 2000;5(3):196-208.
  13. Duan KM, Wang SY, Ouyang W, Mao YM, Yang LJ. Effect of quercetin on CYP3A activity in Chinese healthy participants. J Clin Pharmacol 2012;52(6):940-6. PubMed
  14. Wang SY, Duan KM, Li Y, et al. Effect of quercetin on P-glycoprotein transport ability in Chinese healthy subjects. Eur J Clin Nutr 2013;67(4):390-4. PubMed
  15. Nguyen MA, Staubach P, Wolffram S, Langguth P. Effect of single-dose and short-term administration of quercetin on the pharmacokinetics of talinolol in humans - Implications for the evaluation of transporter-mediated flavonoid-drug interactions. Eur J Pha PubMed
  16. Wu LX, Guo CX, Chen WQ, et al. Inhibition of the organic anion-transporting polypeptide 1B1 by quercetin: an in vitro and in vivo assessment. Br J Clin Pharmacol 2012;73(5):750-7.
  17. Ahrens MJ, Thompson DL. Effect of emulin on blood glucose in type 2 diabetics. J Med Food. 2013;16(3):211-5. PubMed
  18. Larson A, Witman MA, Guo Y, et al. Acute, quercetin-induced reductions in blood pressure in hypertensive individuals are not secondary to lower plasma angiotensin-converting enzyme activity or endothelin-1: nitric oxide. Nutr Res. 2012;32(8):557-64. PubMed
  19. Bedada SK, Neerati P. Evaluation of the effect of quercetin treatment on CYP2C9 enzyme activity of diclofenac in healthy human volunteers. Phytother Res. 2018 Feb;32(2):305-311. doi: 10.1002/ptr.5978. PubMed
  20. Zhao Q, Wei J, Zhang H. Effects of quercetin on the pharmacokinetics of losartan and its metabolite EXP3174 in rats. Xenobiotica 2019;49(5):563-8. PubMed
  21. Bhutani P, Rajanna PK, Paul AT. Impact of quercetin on pharmacokinetics of quetiapine: insights from in-vivo studies in wistar rats. Xenobiotica. 2020:1-7.
  22. Li C, Wang X, Bi Y, et al. Potent Inhibitors of Organic Anion Transporters 1 and 3 From Natural Compounds and Their Protective Effect on Aristolochic Acid Nephropathy. Toxicol Sci. 2020;175(2):279-291. PubMed
  23. Ni Y, Duan Z, Zhou D, et al. Identification of Structural Features for the Inhibition of OAT3-Mediated Uptake of Enalaprilat by Selected Drugs and Flavonoids. Front Pharmacol. 2020;11:802. PubMed
  24. Song YK, Yoon JH, Woo JK, et al. Quercetin is a flavonoid breast cancer resistance protein inhibitor with an impact on the oral pharmacokinetics of sulfasalazine in rats. Pharmaceutics 2020;12(5):397. PubMed
  25. Ahmad E, Jahangir M, Ismail MA, et al. Influence of quercetin pretreatment on pharmacokinetics of warfarin in rats. Curr Drug Saf 2022. PubMed
  26. Nambiar A, Kellogg D 3rd, Justice J, et al. Senolytics dasatinib and quercetin in idiopathic pulmonary fibrosis: results of a phase I, single-blind, single-center, randomized, placebo-controlled pilot trial on feasibility and tolerability. EBioMedicine 20 PubMed

See these in context on the Quercetin monograph →

Elderberry 6 references
  1. Barak V, Halperin T, Kalickman I. The effect of Sambucol, a black elderberry-based, natural product, on the production of human cytokines: I. Inflammatory cytokines. Eur Cytokine Netw 2001;12:290-6..
  2. Elderberry (Sambucus species). The Poison Plant Patch, Novia Scotia Museum, 2007. Available at: http://museum.gov.ns.ca/poison/?section=species&id=117 (Accessed 16 October 2009).
  3. European elder. Canadian Poisonous Plants Information System. Available at: http://www.cbif.gc.ca/pls/pp/ppack.jump?p_null=all&p_psn=121&p_type=all&p_sci=comm&p_x=px (Accessed 16 October 2009).
  4. Raus K, Pleschka S, Klein P, Schoop R, Fisher P. Effect of an echinacea-based hot drink versus oseltamivir in Influenza treatment: a randomized, double-blind, double-dummy, multicenter, noninferiority clinical trial. . Curr Ther Res Clin Exp. 2015;20;77:6 PubMed
  5. Ramachandran A, Antala D, Pudasainee P, Panginikkod S, Gupta H. A Plausible Association Between the Use of Elderberry and Autoimmune Hepatitis. Cureus 2022;14(4):e24250. PubMed
  6. Agarwal N, Mangla A. Elderberry interaction with pazopanib in a patient with soft-tissue sarcoma: A case report and literature review. Mol Clin Oncol 2024;20(5):36. PubMed

See these in context on the Elderberry monograph →

Oregano 12 references
  1. Brinker F. Herb Contraindications and Drug Interactions. 2nd ed. Sandy, OR: Eclectic Medical Publications, 1998.
  2. Benito M, Jorro G, Morales C, et al. Labiatae allergy: systemic reactions due to ingestion of oregano and thyme. Ann Allergy Asthma Immunol 1996;76:416-8. PubMed
  3. Chevallier A. Encyclopedia of Herbal Medicine. 2nd ed. New York, NY: DK Publ, Inc., 2000.
  4. Ciganda C, and Laborde A. Herbal infusions used for induced abortion. J Toxicol.Clin Toxicol. 2003;41:235-239. PubMed
  5. Futrell, J. M. and Rietschel, R. L. Spice allergy evaluated by results of patch tests. Cutis 1993;52(5):288-290.
  6. 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
  7. Goun, E., Cunningham, G., Solodnikov, S., Krasnykch, O., and Miles, H. Antithrombin activity of some constituents from Origanum vulgare. Fitoterapia 2002;73(7-8):692-694. PubMed
  8. Lemhadri, A., Zeggwagh, N. A., Maghrani, M., Jouad, H., and Eddouks, M. Anti-hyperglycaemic activity of the aqueous extract of Origanum vulgare growing wild in Tafilalet region. J Ethnopharmacol. 2004;92(2-3):251-256. PubMed
  9. McCue, P., Vattem, D., and Shetty, K. Inhibitory effect of clonal oregano extracts against porcine pancreatic amylase in vitro. Asia Pac.J Clin.Nutr. 2004;13(4):401-408.
  10. Ragi, J., Pappert, A., Rao, B., Havkin-Frenkel, D., and Milgraum, S. Oregano extract ointment for wound healing: a randomized, double-blind, petrolatum-controlled study evaluating efficacy. J.Drugs Dermatol. 2011;10(10):1168-1172.
  11. Singletary K. Oregano: overview of the literature on health benefits. Nutrition Today 2010;45(3):129-38.
  12. Silva MLAE, Lucarini R, Dos Santos FF, et al. Hypoglycemic effect of rosmarinic acid-rich infusion (RosCE) from Origanum vulgare in alloxan-induced diabetic rats. Nat Prod Res 2022;36(17):4525-4531.

See these in context on the Oregano monograph →

Echinacea 51 references
  1. Mullins RJ. Echinacea-associated anaphylaxis. Med J Aust 1998;168:170-1. PubMed
  2. Mullins RJ. Allergic reactions to Echinacea. J Allergy Clin Immunol 2000;104:S340-341 (Abstract 1003).
  3. Chavez ML, Chavez PI. Echinacea. Hosp Pharm 1998;33:180-8.
  4. Grimm W, Muller HH. A randomized controlled trial of the effect of fluid extract of Echinacea purpurea on the incidence and severity of colds and respiratory infections. Am J Med 1999;106:138-43. PubMed
  5. Taylor JA, Weber W, Standish L, et al. Efficacy and safety of echinacea in treating upper respiratory tract infections in children: a randomized controlled trial. JAMA 2003;290:2824-30.. PubMed
  6. Luettig B, Steinmuller C, Gifford GE, et al. Macrophage activation by the polysaccharide arabinogalactan isolated from plant cell cultures of Echinacea purpurea. J Natl Cancer Inst 1989;81:669-75. PubMed
  7. Stimpel M, Proksch A, Wagner H, et al. Macrophage activation and induction of macrophage cytotoxicity by purified polysaccharide fractions from the plant Echinacea purpurea. Infect Immun 1984;46:845-9. PubMed
  8. Budzinski JW, Foster BC, Vandenhoek S, Arnason JT. An in vitro evaluation of human cytochrome P450 3A4 inhibition by selected commercial herbal extracts and tinctures. Phytomedicine 2000;7:273-82. PubMed
  9. Gallo M, Sarkar M, Au W, et al. Pregnancy outcome following gestational exposure to echinacea: A prospective controlled study. Arch Intern Med 2000;160:3141-3. PubMed
  10. Soon SL, Crawford RI. Recurrent erythema nodosum associated with echinacea herbal therapy. J Am Acad Dermatol 2001;44:298-9. PubMed
  11. Mullins RJ, Heddle R. Adverse reactions associated with echinacea: the Australian experience. Ann Allergy Asthma Immunol 2002;88:42-51. PubMed
  12. Logan JL, Ahmed J. Critical hypokalemic renal tubular acidosis due to Sjogren's syndrome: association with the purported immune stimulant echinacea. Clin Rheumatol 2003;22:158-9.
  13. Schulten B, Bulitta M, Ballering-Bruhl B, et al. Efficacy of Echinacea purpurea in patients with a common cold. A placebo-controlled, randomised, double-blind clinical trial. Arzneimittelforschung 2001;51:563-8.. PubMed
  14. Yale SH, Glurich I. Analysis of the inhibitory potential of Ginkgo biloba, Echinacea purpurea, and Serenoa repens on the metabolic activity of cytochrome P450 3A4, 2D6, and 2C9. J Altern Complement Med 2005;11:433-9.
  15. Yale SH, Liu K. Echinacea purpurea therapy for the treatment of the common cold: a randomized, double-blind, placebo-controlled clinical trial. Arch Intern Med 2004;164:1237-41. PubMed
  16. Gorski JC, Huang S, Zaheer NA, et al. The effect of echinacea (Echinacea purpurea root) on cytochrome P450 activity in vivo.Clin Pharmacol Ther 2003;73 (Abstract PDII-A-8):P94. PubMed
  17. Lee AN, Werth VP. Activation of autoimmunity following use of immunostimulatory herbal supplements. Arch Dermatol 2004;140:723-7. PubMed
  18. Goel V, Lovlin R, Barton R, et al. Efficacy of a standardized echinacea preparation (Echinilin) for the treatment of the common cold: a randomized, double-blind, placebo-controlled trial. J Clin Pharm Ther 2004;29:75-83.
  19. Barrett B. Medicinal properties of Echinacea: a critical review. Phytomedicine 2003;10:66-86. PubMed
  20. Huntley AL, Thompson Coon J, Ernst E. The safety of herbal medicinal products derived from Echinacea species: a systematic review. Drug Saf 2005;28:387-400. PubMed
  21. Turner RB, Bauer R, Woelkart K, et al. An evaluation of Echinacea angustifolia in experimental rhinovirus infections. N Engl J Med 2005;353:341-8.
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