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

Zinc Defense Ingredients & Drug Interactions

by Pure TheraPro Rx

Zinc Defense label
See full label image
Capsule Category: Other Combinations
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 30, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Zinc Defense 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

Zinc Defense is a dietary supplement by Pure TheraPro Rx with 3 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, 1,184 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Quercetin, Zinc, Copper. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

Jump to a section

Check Your Meds Against Zinc Defense by Pure TheraPro Rx

Ask about any prescription or over-the-counter medication and we check it for interactions with Zinc Defense by Pure TheraPro Rx — and tell you which ingredient is responsible.

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

HelloPharmacist Scorecard of Zinc Defense by Pure TheraPro Rx

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 Oct 1, 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 3 of its 3 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

Zinc Defense contains three active ingredients. Copper is included to support copper nutrition and help prevent deficiency.

Zinc serves multiple roles—it supports immune function, wound healing, and is effective for zinc deficiency and Wilson disease. Quercetin is a plant compound (flavonoid) added for its antioxidant properties, though evidence for its specific health claims is still being studied.

The capsule itself is made from DRcaps, an inactive ingredient.

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
Strong

Clinical evidence supports at least one of this product's ingredients for its stated purpose.

Why this rating?
  • The label markets this product for: support innate and adaptive immunity.
  • We looked for evidence on: Acne, Copper deficiency, Canker sores, Herpes labialis (cold sores), Exercise-induced respiratory infections, HIV/AIDS-related opportunistic infections — and 4 related terms.
  • The strongest evidence on file: Copper is rated "Likely Effective" for Copper deficiency (Natural Medicines).
  • Also on file: Zinc is rated "Possibly Effective" for Acne, Herpes labialis (cold sores), Child growth.
  • Also on file: Quercetin is rated "Insufficient Reliable Evidence To Rate" for Exercise-induced respiratory infections, Herpes labialis (cold sores), Canker sores.

Of the three actives, zinc is the most well-established: it's effective for zinc deficiency and likely effective for Wilson disease, and possibly effective for acne and age-related macular degeneration. Copper is likely effective for copper deficiency but appears possibly ineffective for Alzheimer disease.

Quercetin's effectiveness is less clear—the data we hold shows insufficient evidence for most uses, and it appears possibly ineffective for athletic performance. If you're taking this for a specific condition, talk with your doctor or pharmacist about whether the evidence supports using it.

The evidence, ingredient by ingredient Copper Zinc Quercetin

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 3 of the 3 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 3 of 3.
  • General safety write-ups exist for 3 of 3.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Zinc is generally well tolerated at recommended doses, but high doses can cause stomach upset (cramps, diarrhea, nausea) and a metallic taste. Copper is safe in food and standard supplement amounts, but excess copper can be toxic; long-term high-dose zinc can increase the risk of copper deficiency.

Quercetin is generally well tolerated in food amounts and typical supplement doses, but long-term safety at higher doses isn't well studied. For pregnancy, copper and zinc are considered likely safe in recommended amounts; quercetin, however, lacks enough safety data—avoid supplemental doses during pregnancy or while breastfeeding unless your doctor advises otherwise.

Side effects, ingredient by ingredient Copper Zinc Quercetin

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?
  • 3 of the 3 matched ingredients can interact with medications — Quercetin, Copper, Zinc.
  • 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: 1,185 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 Zinc Defense, check with your doctor or pharmacist if you take penicillamine (a chelating agent for Wilson disease), any antibiotic—including quinolones, cephalexin, tetracyclines, or penicillamine—blood thinners like warfarin, blood pressure medications like losartan, cholesterol drugs like pravastatin, HIV antivirals including ritonavir or integrase inhibitors, chemotherapy drugs like cisplatin or mitoxantrone, cyclosporine (an immunosuppressant), sulfasalazine, or birth control pills. Separate dosing may be needed for several of these drug types.

Check your own medication Run your meds through the checker above

The bottom line

Scorecard at a glanceFully disclosed formula with clinical evidence supporting its stated purpose. Moderate medication interactions have been identified, and safety information is well characterized.

Zinc Defense may be worth considering if you have or suspect a zinc or copper deficiency, or if your doctor has suggested zinc for a condition like acne or macular degeneration. However, the ingredient list means you'll want to double-check your current medications—especially antibiotics, blood thinners, blood pressure drugs, and HIV medications—before starting.

Talk with your own doctor or pharmacist about whether this product is right for you and whether the timing of doses needs adjustment.

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

Assessment coverage: 3 of 3 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Jan 24, 2024.

This Scorecard evaluates available label information, ingredient evidence, and known medication-safety considerations. It does not independently verify product identity, purity, potency, contamination, or manufacturing quality. How these ratings are computed

At a glance

General information

Key facts about Zinc Defense, straight from the product label.

Brand Pure TheraPro Rx
Barcode (UPC) X0036YSIF7
Net contents 120 Delayed-Release Capsule(s)
Market status On market
Date entered into DSLD Jan 24, 2024
DSLD ID 305970
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Vegan, Vegetarian, Adult (18 - 50 Years), Gluten Free, Dairy 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 Zinc Defense by Pure TheraPro Rx, 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 Capsule(s)
Maximum serving Sizes:
1 Capsule(s)
Servings per container
120
UPC/BARCODE
X0036YSIF7
IngredientAmount% DV
Copper1 mg111%
Zinc15 mg136%
Quercetin250 mg--

Other ingredients: DRcaps

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: Take one (1) capsule one to two times daily, or as directed by a healthcare practitioner. Best taken with food.

Precautions

Warning: Individuals taking medication, children and pregnant or lactating women should consult their healthcare practitioner prior to use. Do not use if you have severe immune suppression condition. If taking anti-fungal(s), consume at least 2 hours prior or after.

Warning: Individuals taking medication, children and pregnant or lactating women should consult their healthcare practitioner prior to use.

Do not use if tamper seal is damaged.

Keep out of reach of children.

Formula

Zinc Defense is a well-studied solution containing clinically-backed ingredients specifically formulated to support innate and adaptive immunity. L-OptiZinc, a mineral-amino acid chelate, boasts over 120% the absorption and retention of other forms of Zinc. TRAACS Copper Bisglycinate Chelate is smartly paired with Zinc to create a powerful antioxidant enzyme for defense against oxidative stress while maintaining the body's delicate Zinc-Copper balance. Quercefit (Phytosomal Quercetin) is proven to enhance quercetin bioavailability by up to 20x and performs the role of an ionophore; transporting Zinc across the membrane and into the cell where it is required most.

Ionophore

Storage

Storage: Keep tightly closed in a cool, dry place.

Formulation

Formulated to exclude: Fillers, gluten, wheat, soy, corn, yeast, animal or dairy products, shellfish, fish, peanuts, tree nuts, egg, ingredients derived from genetically modified organisms (GMO's), artificial preservatives, sweeteners or colors.

V Vegan

Powerful immune & respiratory support complex

Formulated, tested & packaged in the USA

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.

Seals/Symbols

GMP Certified Good Manufacturing Practice

FDA Statement of Identity

Professional Dietary Supplement

Brand IP Statement(s)

Quercefit Quercefit is a registered trademark of Indena S.p.A. Italy. TRAACS is a registered trademark of Albion Laboratories, Inc.

L-OptiZinc L-OptiZinc is a Lonza trademark.

Drcaps Drcaps & logo are trademarks of Lonza or its affiliates.

Copyright 2022 Pure Therapro Rx

General Statements

Please recycle

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

See for yourself

Zinc Defense by Pure TheraPro Rx label

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

Zinc Defense 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 Zinc Defense by Pure TheraPro Rx

These are the 3 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container120 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
1 mg per serving Form: Copper Bisglycinate

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

Zinc

Interacts with
67 drugs
15 mg per serving Form: L-OptiZinc

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

Quercetin

Interacts with
1,169 drugs
250 mg per serving Form: Quercefit

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

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

Interaction report

Zinc Defense by Pure TheraPro Rx Drug Interactions

Want to check YOUR meds against Zinc Defense?

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
1,184Drugs
1,181 Moderate 3 Minor

Ingredients driving the most interactions

Quercetin 1,169
Zinc 67
Copper 31

Individual Drug Interactions

The ingredients in Zinc Defense interact with 1,184 drugs. Click any drug to see the details.

3 of the 3 ingredients in Zinc Defense interact with drugs. Each result below shows which ingredient is responsible. Quercetin Zinc Copper

Each ingredient & the kinds of drugs it affects

For each ingredient in Zinc Defense 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

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 Zinc Defense, from the product label.

Pure TheraPro Rx

See all Pure TheraPro Rx products
Name
Pure TheraPro Rx
Street Address
8781 Sheridan Blvd #6080
City
Westminster
State
CO
ZipCode
80003
Phone Number
888-655-4648
Web Address
Purethera.com
Pharmacist Counseling Corner

Zinc Defense by Pure TheraPro Rx: Common Questions

Does Zinc Defense by Pure TheraPro Rx interact with any medications?
Yes. Based on its ingredients, Zinc Defense has a known interaction with 1,184 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Zinc Defense contains 3 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 Zinc Defense if I'm pregnant or breastfeeding?
Copper and zinc are considered likely safe in recommended amounts during both pregnancy and lactation. Quercetin, however, doesn't have enough safety data—avoid supplemental doses of quercetin during pregnancy or while breastfeeding. Talk with your doctor or pharmacist before starting any supplement during pregnancy or nursing.
What does each ingredient in Zinc Defense actually do?
Zinc supports immune function and wound healing and is used to treat zinc deficiency and Wilson disease. Copper is included to prevent copper deficiency. Quercetin is a plant antioxidant, though evidence for most health claims is still being studied.
Can this supplement cause side effects?
Zinc may cause stomach cramps, diarrhea, nausea, or a metallic taste, especially at higher doses. Copper is safe in standard amounts but can be toxic in excess. Quercetin may cause headache or tingling in the extremities. If you experience any of these, stop and talk with your pharmacist.
Will this help with acne or age-related eye problems?
Zinc is possibly effective for acne, so it may help some people. For age-related macular degeneration, zinc is possibly effective. Quercetin's role in either condition lacks solid evidence. Your doctor is best placed to advise whether this product is right for your specific situation.
What happens if I take this with antibiotics?
Zinc can reduce absorption of quinolone antibiotics, cephalexin (Keflex), and tetracycline antibiotics. Your pharmacist can advise you to take the antibiotic and this supplement several hours apart. Do not skip this step—it matters for how well the antibiotic works.
Is there copper in this product even though it's called 'Zinc Defense'?
Yes, this product contains copper as one of its three active ingredients. This is important to know if you have a condition that affects copper levels or if you take certain medications that interact with copper, like penicillamine.

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

Not sure if Zinc Defense is safe with your meds?

Our pharmacists answer your medication & supplement questions — free.

Ask a pharmacist

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

Zinc Defense label
Go deeper

The Full Monographs Behind Zinc Defense’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

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 → 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 →
Sources

Sources & How We Checked

Zinc Defense'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 125 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 →

Zinc 88 references
  1. Barceloux DG. Zinc. J Toxicol Clin Toxicol 1999;37:279-92.
  2. Eby GA, Davis DR, Halcomb WW. Reduction in duration of common colds by zinc gluconate lozenges in a double-blind study. Antimicrob Agents Chemother 1984;25:20-4. DOI
  3. Smith DS, Helzner EC, Nuttall CE Jr, et al. Failure of zinc gluconate in treatment of acute upper respiratory tract infections. Antimicrob Agents Chemother 1989;33:646-8. PubMed
  4. Blondeau JM. Expanded activity and utility of the new fluoroquinolones: a review. Clin Ther 1999;21:3-40. PubMed
  5. Reyes AJ, Olhaberry JV, Leary WP, et al. Urinary zinc excretion, diuretics, zinc deficiency and some side-effects of diuretics. S Afr Med J 1983;64:936-41.
  6. Kugelmas M. Preliminary observation: oral zinc sulfate replacement is effective in treating muscle cramps in cirrhotic patients. J Am Coll Nutr 2000;19:13-5. PubMed
  7. Hebel SK, ed. Drug Facts and Comparisons. 52nd ed. St. Louis: Facts and Comparisons, 1998.
  8. Chan S, Gerson B, Subramaniam S. The role of copper, molybdenum, selenium, and zinc in nutrition and health. Clin Lab Med 1998;18:673-85. DOI
  9. Brewer GJ, Yuzbasiyan-Gurkan V, Johnson V, et al. Treatment of Wilson's disease with zinc: XI. Interaction with other anticopper agents. J Am Coll Nutr 1993;12:26-30. PubMed
  10. Fosmire GJ. Zinc toxicity. Am J Clin Nutr 1990;51:225-7.
  11. Lomaestro BM, Bailie GR. Absorption interactions with fluoroquinolones. 1995 update. Drug Saf 1995;12:314-33. PubMed
  12. Hansten PD, Horn JR. Drug Interactions Analysis and Management. Vancouver, WA: Applied Therapeutics Inc., 1997 and updates.
  13. Seelig MS. Auto-immune complications of D-penicillamine - A possible result of zinc and magnesium depletion and of pyridoxine inactivation. J Am Coll Nutr 1982;1:207-14. PubMed
  14. Neuvonen PJ. Interactions with the absorption of tetracyclines. Drugs 1976;11:45-54.. PubMed
  15. Hirt M, Nobel S, Barron E. Zinc nasal gel for the treatment of common cold symptoms: A double-blind, placebo-controlled trial. Ear Nose Throat J 2000;79:778-82.. DOI
  16. Simkin PA. Oral zinc sulphate in rheumatoid arthritis. Lancet 1976;2:539-42. PubMed
  17. Wray D. A double-blind trial of systemic zinc sulfate in recurrent aphthous stomatitis. Oral Surg Oral Med Oral Pathol 1982;53:469-72. PubMed
  18. Douglas RM, Miles HB, Moore BW, et al. Failure of effervescent zinc acetate lozenges to alter the course of upper respiratory tract infections in Australian adults. Antimicrob Agents Chemother 1987;31:1263-5. PubMed
  19. Lagiou P, Wuu J, Trichopoulou A, et al. Diet and benign prostatic hyperplasia: a study in Greece. Urology 1999;54:284-90. PubMed
  20. Ewing CI, Gibbs AC, Ashcroft C, David TJ. Failure of oral zinc supplementation in atopic eczema. Eur J Clin Nutr 1991;45:507-10.
  21. 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.
  22. Age-Related Eye Disease Study Research Group. A randomized, placebo-controlled, clinical trial of high-dose supplementation with vitamins C and E, beta carotene, and zinc for age-related macular degeneration and vision loss. AREDS report no. 8. Arch Oph
  23. Greenberg JE, Lynn M, Kirsner RS, et al. Mucocutaneous pigmented macule as a result of zinc deposition. J Cutan Pathol 2002;29:613-5. PubMed
  24. Godfrey HR, Godfrey NJ, Godfrey JC, Riley D. A randomized clinical trial on the treatment of oral herpes with topical zinc oxide/glycine. Altern Ther Health Med 2001;7:49-56.
  25. Turner RB. Ineffectiveness of intranasal zinc gluconate for prevention of experimental rhinovirus colds. Clin Infect Dis 2001;33:1865-70. PubMed
  26. Belongia EA, Berg R, Liu K. A randomized trial of zinc nasal spray for the treatment of upper respiratory illness in adults. Am J Med 2001;111:103-8. PubMed
  27. Mossad SB. Effect of zincum gluconicum nasal gel on the duration and symptom severity of the common cold in otherwise healthy adults. QJM 2003;96:35-43. DOI
  28. Leitzmann MF, Stampfer MJ, Wu K, et al. Zinc supplement use and risk of prostate cancer. J Natl Cancer Inst 2003;95:1004-7.. PubMed
  29. Jafek BW, Linschoten M, Murrow BW. Zicam Induced Anosmia. American Rhinologic Society 49th Annual Fall Scientific Meeting abstract. Orlando, Florida. September 20, 2003. http://app.american-rhinologic.org/programs/2003ARSFallProgram071503.pdf (Accessed 24
  30. Uebayashi H, Hatanaka T, Kanemura F, Tonosaki K. Acute anosmia in the mouse: behavioral discrimination among the four basic taste substances. Physiol Behav 2001;72:291-6.. PubMed
  31. Barrett S. Zicam Marketers Sued. United States District Court Western District of Michigan Southern Division, Filed October 14, 2003, Case No. 4:03CV0146.
  32. Bilici M, Yildirim F, Kandil S, et al. Double-blind, placebo-controlled study of zinc sulfate in the treatment of attention deficit hyperactivity disorder. Prog Neuropsychopharmacol Biol Psychiatry 2004;28:181-90.. PubMed
  33. Polk RE, Healy DP, Sahai J, et al. Effect of ferrous sulfate and multivitamins with zinc on absorption of ciprofloxacin in normal volunteers. Antimicrob Agents Chemother 1989;33:1841-4. PubMed
  34. Mery C, Delrieu F, Ghozlan R, et al. Controlled trial of D-penicillamine in rheumatoid arthritis. Dose effect and the role of zinc. Scand J Rheumatol 1976;5:241-7. PubMed
  35. Penttila O, Hurme H, Neuvonen PJ. Effect of zinc sulfate on the absorption of tetracycline and doxycycline in man. Eur J Clin Pharmacol 1975;9:131-4.
  36. Kondo Y, Yamagata K, Satoh M, et al. Optimal administration schedule of cisplatin for bladder tumor with minimal induction of metallothionein. J Urol 2003;170:2467-70. PubMed
  37. Doz F, Berens ME, Deschepper CF, et al. Experimental basis for increasing the therapeutic index of cis-diamminedicarboxylatocyclobutaneplatinum(II) in brain tumor therapy by a high-zinc diet. Cancer Chemother Pharmacol 1992;29:219-26.
  38. Wester PO. Urinary zinc excretion during treatment with different diuretics. Acta Med Scand 1980;208:209-12. PubMed
  39. Golik A, Modai D, Weissgarten J, et al. Hydrochlorothiazide-amiloride causes excessive urinary zinc excretion. Clin Pharmacol Ther 1987;42:42-4. PubMed
  40. Leary WP, Reyes AJ, Van der Byl K. Urinary magnesium and zinc excretion after two different single doses of amiloride in healthy adults. Curr Ther Res 1983;34:205-16.
  41. McBride K, Slotnick B, Margolis FL. Does intranasal application of zinc sulfate produce anosmia in the mouse? An olfactometric and anatomical study. Chem Senses 2003;28:659-70. PubMed
  42. Burd GD. Morphological study of the effects of intranasal zinc sulfate irrigation on the mouse olfactory epithelium and olfactory bulb. Microsc Res Tech 1993;24:195-213. PubMed
  43. Ducray A, Bondier JR, Michel G, et al. Recovery following peripheral destruction of olfactory neurons in young and adult mice. Eur J Neurosci 2002;15:1907-17. PubMed
  44. Mayer AD, Rosenblatt JS. Peripheral olfactory deafferentation of the primary olfactory system in rats using ZnSO4 nasal spray with special reference to maternal behavior. Physiol Behav 1993;53:587-92. PubMed
  45. DeCook CA, Hirsch AR. Anosmia due to inhalational zinc: a case report (abstract). Chem Senses 2000;25:659.
  46. Tisdall FF, Brown A, Defries RD. Persistent anosmia following zinc sulfate nasal spraying. JPed 1938;18:60-2. DOI
  47. Lawson KA, Wright ME, Subar A, et al. Multivitamin use and risk of prostate cancer in the National Institutes of Health-AARP Diet and Health Study. J Natl Cancer Inst 2007;99:754-64. PubMed
  48. Public Health Advisory. Loss of sense of smell with intranasal cold remedies containing zinc. U.S. Food and Drug Administration, June 16, 2009. Available at: http://www.fda.gov/Drugs/DrugSafety/PublicHealthAdvisories/ucm166059.htm (Accessed 16 June 2009)
  49. Dooren JC. FDA warns against use of Zicam. The Wall Street Journal, June 16, 2009. Available at: http://online.wsj.com/article/SB124516778692319231.html#mod=djemHL?mg=com-wsj (Accessed 16 June 2009).
  50. Alexander TH, Davidson TM. Intranasal zinc and anosmia: the zinc-induced anosmia syndrome. Laryngoscope 2006;116:217-20.
  51. Health Canada / GlaxoSmithKline Consumer Healthcare. Association of long-term, excessive use of zinc-containing Poli-Grip products with myeloneuropathy and blood dyscrasias. February 18, 2010. Available at: http://hc-sc.gc.ca/dhp-mps/alt_formats/pdf/medef
  52. GlaxoSmithKline Consumer Advisory. GlaxoSmithKline (GSK) warns about a potential health risk associated with long-term, excessive use of GSK's zinc-containing denture adhesives Super Polygrip Original, Ultra Fresh and Extra Care. February 18, 2010. Availa
  53. Science M, Johnstone J, Roth DE, et al. Zinc for the treatment of the common cold: a systematic review and meta-analysis of randomized controlled trials. CMAJ 2012;184:E551-61. PubMed
  54. Castilla-Higuero, L., Romero-Gomez, M., Suarez, E., and Castro, M. Acute hepatitis after starting zinc therapy in a patient with presymptomatic Wilson's disease. Hepatology 2000;32(4 Pt 1):877. PubMed
  55. Sharquie, K. E., Najim, R. A., Farjou, I. B., and Al Timimi, D. J. Oral zinc sulphate in the treatment of acute cutaneous leishmaniasis. Clin.Exp.Dermatol. 2001;26(1):21-26. PubMed
  56. Dreno, B., Moyse, D., Alirezai, M., Amblard, P., Auffret, N., Beylot, C., Bodokh, I., Chivot, M., Daniel, F., Humbert, P., Meynadier, J., and Poli, F. Multicenter randomized comparative double-blind controlled clinical trial of the safety and efficacy of
  57. Moore, R. Bleeding gastric erosion after oral zinc sulphate. Br.Med J 3-25-1978;1(6115):754. PubMed
  58. Jafek, B. W., Linschoten, M. R., and Murrow, B. W. Anosmia after intranasal zinc gluconate use. Am J Rhinol. 2004;18(3):137-141. DOI
  59. Simonart, T. and de, Maertelaer, V. Systemic treatments for cutaneous warts: a systematic review. J Dermatolog.Treat. 2012;23(1):72-77. PubMed
  60. Cochran, R. J., Tucker, S. B., and Flannigan, S. A. Topical zinc therapy for acne vulgaris. Int.J Dermatol. 1985;24(3):188-190. DOI
  61. Morgan, A. A. Bleeding gastric erosion after oral zinc sulphate. Br.Med.J. 5-13-1978;1(6122):1283-1284. PubMed
  62. Murphy, J. V. Intoxication following ingestion of elemental zinc. JAMA 6-22-1970;212(12):2119-2120.
  63. Lang, C. J., Rabas-Kolominsky, P., Engelhardt, A., Kobras, G., and Konig, H. J. Fatal deterioration of Wilson's disease after institution of oral zinc therapy. Arch Neurol. 1993;50(10):1007-1008. PubMed
  64. Fjellner, B. Drug-induced lupus erythematosus aggravated by oral zinc therapy. Acta Derm.Venereol. 1979;59(4):368-370. DOI
  65. Varas Lorenzo, M. J. Zinc acexamate and ranitidine in the short- and mid-term management of gastroduodenal ulcers. Curr Ther Res 21986;39:19-29.
  66. Bosch, F. and Jimenez, E. Post-marketing surveillance of zinc acexamate in peptic ulcer treatment. Clin Trials J 1990;27:301-312.
  67. DeCook, C. A. and Hirsch, A. R. Anosmia due to inhalational zinc: a case report (abstract). Chem Senses 2000;25:659.
  68. Crown LA, May JA. Zinc toxicity: denture adhesives, bone marrow failure and polyneuropathy. Tenn Med. 2012 Feb;105(2):39-40, 42.
  69. Dadamio J, Van Tournout M, Teughels W, Dekeyser C, Coucke W, Quirynen M. Efficacy of different mouthrinse formulations in reducing oral malodour: a randomized clinical trial. J Clin Periodontol. 2013 May;40(5):505-13. PubMed
  70. Moyle G, Else L, Jackson A, Back D, Yapa MH, Seymour N, Ringner-Nackter L, Karolia Z, Gazzard B, Boffito M. Coadministration of atazanavir-ritonavir and zinc sulfate: impact on hyperbilirubinemia and pharmacokinetics. Antimicrob Agents Chemother. 2013 Aug PubMed
  71. Zittel S, Ufer F, Gerloff C, Münchau A, Rosenkranz M. Severe myelopathy after denture cream use--is copper deficiency or excess zinc the cause? Clin Neurol Neurosurg. 2014 Jun;121:17-8. PubMed
  72. Jalloh MA, Gregory PJ, Hein D, et al. Dietary supplement interactions with antiretrovirals: a systematic review. Int J STD AIDS. 2017 Jan;28(1):4-15. PubMed
  73. Guidelines for the Use of Antiretroviral Agents in HIV-1-Infected Adults and Adolescents: Drug Interactions between Integrase Inhibitors and Other Drugs. AIDSinfo. July 14, 2016. Available at: https://aidsinfo.nih.gov/guidelines/html/1/adult-and-adolescen
  74. Ding Y, Jia YY, Li F, et al. The effect of staggered administration of zinc sulfate on the pharmacokinetics of oral cephalexin. Br J Clin Pharmacol. 2012 Mar;73(3):422-7. PubMed
  75. Fallah R, Sabbaghzadegan S, Karbasi SA, Binesh F. Efficacy of zinc sulfate supplement on febrile seizure recurrence prevention in children with normal serum zinc level: A randomised clinical trial. Nutrition. 2015;31(11-12):1358-61. PubMed
  76. Lazzerini M, Wanzira H. Oral zinc for treating diarrhoea in children. Cochrane Database Syst Rev. 2016;12:CD005436. PubMed
  77. Mahmoud AM, Al-Alem U, Dabbous F, et al. Zinc intake and risk of prostate cancer: Case-control study and meta-analysis. PLoS One. 2016;11(11):e0165956. PubMed
  78. Nagraj SK, George RP, Shetty N, Levenson D, Ferraiolo DM, Shrestha A. Interventions for managing taste disturbances. Cochrane Database Syst Rev. 2017 Dec 20;12(12):CD010470. PubMed
  79. Yee BE, Richards P, Sui JY, Marsch AF. Serum zinc levels and efficacy of zinc treatment in acne vulgaris: A systematic review and meta-analysis. Dermatol Ther. 2020:e14252. PubMed
  80. Janyajirawong R, Vilaichone RK, Sethasine S. Efficacy of zinc supplement in minimal hepatic encephalopathy: A prospective, randomized controlled study (Zinc-MHE Trial). Asian Pac J Cancer Prev 2021;22(9):2879-2887. PubMed
  81. Nakano M, Nakamura Y, Miyazaki A, Takahashi J. Zinc pharmacotherapy for elderly osteoporotic patients with zinc deficiency in a clinical setting. Nutrients 2021;13(6):1814. PubMed
  82. Tolino E, Skroza N, Mambrin A, et al. An open-label study comparing oral zinc to lymecycline in the treatment of acne vulgaris. J Clin Aesthet Dermatol 2021;14(5):56-58.
  83. Hunter J, Arentz S, Goldenberg J, et al. Zinc for the prevention or treatment of acute viral respiratory tract infections in adults: a rapid systematic review and meta-analysis of randomised controlled trials. BMJ Open. 2021;11(11):e047474. PubMed
  84. Yamazaki K, Kageyama H, Fujiyama T, Ito T, Urano S, Honda T. A case of systemic contact dermatitis due to zinc supplements. Int J Dermatol 2022. PubMed
  85. Magham K, Han J, Eilbert W, Bunney EB. Severe copper deficiency anemia caused by zinc supplement use. Am J Emerg Med 2023;72:222. PubMed
  86. Sivakumar RR, Chinnaiah Govindareddy D, Sahoo J, Bobby Z, Chinnakali P. Effect of daily zinc supplementation for 12 weeks on serum thyroid auto-antibody levels in children and adolescents with autoimmune thyroiditis - a randomized controlled trial. J Pedi PubMed
  87. AlDhasee O, AlMalki H, AlKharashi N, AlJeraisy N, Al Deeb M. Acute zinc sulfate overdose: clinical presentation and management. BMJ Case Rep 2025;18(1):e263899. PubMed
  88. US Food and Drug Administration (FDA). Biktarvy Prescribing Information. October 2024. Available at: https://www.accessdata.fda.gov/drugsatfda_docs/label/2024/210251Orig1s020lbl.pdf. Accessed July 16, 2025.

See these in context on the Zinc 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 →

Parts of this content are provided by the Therapeutic Research Center, LLC.

DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

© 2021 Therapeutic Research Center, LLC

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