Major interaction on record — check this product against your medications before combining. Check your meds →
Dietary supplement

Zinc + A & C Ingredients & Drug Interactions

by Indiana Botanic Gardens

Zinc + A & C label
See full label image
Lozenge Category: Botanical
Most serious interaction: Major
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Zinc + A & C 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: Major

Zinc + A & C is a dietary supplement by Indiana Botanic Gardens with 7 active ingredients. Its ingredients are commonly taken for common cold and immune support, antioxidant support, skin health and collagen formation.Based on those ingredients, 2,271 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are Slippery Elm, Goldenseal, Bee Propolis. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Zinc + A & C by Indiana Botanic Gardens

Ask about any prescription or over-the-counter medication and we check it for interactions with Zinc + A & C by Indiana Botanic Gardens — and tell you which ingredient is responsible.

Pharmacist-reviewed data Checks every ingredient Answer in seconds
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HelloPharmacist Scorecard of Zinc + A & C by Indiana Botanic Gardens

Our pharmacy team’s full take, with four database checks built into the cards below — a summary of what is known, not a grade of the product itself.

From our pharmacy team — supplement deep dive

Generated from HelloPharmacist’s pharmacist-curated databases and editorial rules · Last generated Jul 11, 2026

What’s inside

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 7 of its 7 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

This lozenge contains 7 active ingredients: vitamin C, vitamin A, bee propolis, zinc, goldenseal root, slippery elm bark, and echinacea purpurea. Vitamin C supports immunity and acts as an antioxidant; vitamin A is essential for vision and skin health; zinc helps with immune function and wound healing; bee propolis is a resinous compound made by bees with traditional antimicrobial properties; goldenseal root contains berberine, an alkaloid used in herbal medicine; slippery elm bark contains mucilage to soothe irritated tissues; and echinacea is traditionally used to support immune response.

The product also contains inactive ingredients including cellulose, citric acid, natural flavors, stearic acid, silica, xanthan gum, magnesium stearate, beet powder, and acerola.

Does it work?

Moderate 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
Moderate

Some clinical evidence supports this product's ingredients for its stated purpose, but it isn't conclusive.

Why this rating?
  • The label markets this product for: Supports immune system.
  • We looked for evidence on: Acute bronchitis, Common cold, Flu, Respiratory infection.
  • The strongest evidence on file: Vitamin C is rated "Possibly Effective" for Exercise-induced respiratory infections (Natural Medicines).
  • Also on file: Vitamin C is rated "Possibly Ineffective" for Acute bronchitis.
  • Also on file: Propolis is rated "Insufficient Reliable Evidence To Rate" for Common cold.

Evidence for this product's ingredients is mixed. Vitamin C is effective for preventing vitamin C deficiency and possibly effective for certain types of anemia, exercise-related respiratory infections, cataracts, and atrial fibrillation.

Vitamin A is effective for vitamin A deficiency and possibly effective for oral leukoplakia, aging skin, measles, ulcerative colitis, and bronchopulmonary dysplasia. Zinc is effective for zinc deficiency and Wilson disease, and possibly effective for acne, age-related macular degeneration, and diabetes.

Bee propolis is possibly effective for oral mucositis and cold sores, and possibly effective for diabetes. Goldenseal and echinacea have insufficient or no reliable evidence for most uses listed in our data.

Slippery elm has insufficient evidence for all uses we hold data for. The overall effectiveness of this combination for any single condition isn't established in our data.

The evidence, ingredient by ingredient Vitamin C Vitamin A Propolis Zinc Goldenseal Slippery Elm Echinacea

How safe is it?

Well-documented data
Safety Information · database check
Well characterized

Adverse-effect, pregnancy, and general safety data are on file for most of these ingredients.

Why this rating?
  • We hold adverse-effect (side-effect) data for 7 of the 7 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 7 of 7.
  • General safety write-ups exist for 7 of 7.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

The product is generally well tolerated at normal doses. Vitamin C at high doses can cause stomach upset, diarrhea, nausea, and kidney stones in susceptible people; most side effects occur above 2 grams daily.

Vitamin A is safe at recommended amounts but builds up in the body—high doses carry rare risks of liver damage and serious neurological effects. Zinc at recommended levels is well tolerated; high doses above 40 mg daily may cause nausea, diarrhea, and a metallic taste.

Bee propolis can trigger allergic reactions, especially in people sensitive to bee products, and about 7% of people in trials reported mild headache. Goldenseal and echinacea have limited safety data; echinacea may cause allergic reactions in people sensitive to ragweed.

Slippery elm can cause contact dermatitis from topical exposure. Regarding pregnancy and breastfeeding: vitamin C normal amounts are likely safe, but high-dose supplements are possibly unsafe; vitamin A at recommended amounts is likely safe but high doses are possibly unsafe and carry birth-defect risk; no safety data are on file for bee propolis, goldenseal, slippery elm, or echinacea in pregnancy or lactation—these should be avoided unless your doctor approves.

Side effects, ingredient by ingredient Vitamin C Vitamin A Propolis Zinc Goldenseal Slippery Elm Echinacea

Meds to double-check

Major interaction found
Known Interaction Concern · database check
Major identified

At least one ingredient has a documented Major-severity interaction. Check your medications for a personalized result.

Why this rating?
  • 7 of the 7 matched ingredients can interact with medications — Propolis, Goldenseal, Vitamin A, Slippery Elm, Echinacea, among others.
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; immunosuppressants / transplant drugs; cancer treatments; diabetes medications; heart-rhythm medications.
  • For scale: 2,272 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.

If you take retinoid drugs (isotretinoin, tretinoin), do not use this product without talking to your doctor first—Major interaction risk. For other medications: check blood thinners (warfarin), oral contraceptives and hormone replacement therapy, antibiotics (especially quinolones, tetracyclines, and cephalexin), thyroid drugs (levothyroxine), HIV medications (ritonavir, integrase inhibitors), chemotherapy drugs, and any drug broken down by your liver (your pharmacist can tell you which ones).

All of these carry Moderate interaction potential with one or more ingredients in this product.

Check your own medication Run your meds through the checker above

The bottom line

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

This is a multivitamin-and-herb lozenge best suited for people seeking immune support or general micronutrient supplementation at normal doses. If you take any prescription medication—especially birth control, blood thinners, antibiotics, HIV drugs, or thyroid medication—check your exact drugs with the tool on this page before starting.

Avoid this product if you use retinoid acne or anti-aging drugs, and talk with your pharmacist or doctor before use if you're pregnant, breastfeeding, or managing a chronic condition.

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

Assessment coverage: 7 of 7 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Feb 25, 2013.

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 + A & C, straight from the product label.

Brand Indiana Botanic Gardens
Barcode (UPC) 703308090253
Net contents 50 Lozenge(s)
Market status On market
Date entered into DSLD Feb 25, 2013
DSLD ID 18254
Product type Botanical
Supplement form Lozenge
Dietary claims / uses Nutrient, All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Children (All)
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 + A & C by Indiana Botanic Gardens, 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 Lozenge(s)
Maximum serving Sizes:
1 Lozenge(s)
UPC/BARCODE
703308090253
IngredientAmount% DV
Calories5 {Calories}--
Total Carbohydrates2 g1%
Vitamin C150 mg250%
Vitamin A1000 IU20%
Bee Propolis5 mg--
Zinc12 mg80%
Goldenseal5 mg--
Sugar Alcohols2 g--
Slippery Elm5 mg--
Echinacea purpurea5 mg--

Other ingredients: natural Raspberry flavor, Cellulose, Citric Acid, natural Pineapple flavor, Stearic Acid, Silica, Xanthan Gum, natural Vanilla flavor, Magnesium Stearate, Beet powder, Acerola

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

Suggested Use: For high-intensity use, take one lozenge every two wakeful hours, dissolving completely in mouth. Otherwise, take one lozenge per day, as a dietary supplement, or as directed by a physician. Do not exceed 10 lozenges per day. For children under 60 pounds, use 1/2 adult amount.

Precautions

For your protection, this container has an outer safety seal. (Do not accept if missing or broken.)

KEEP OUT OF REACH OF CHILDREN

Warning: If you are taking any medications or are pregnant or nursing do not use prior to consulting a physician.

General Statements

Best if used by date on bottle.

Supports Your Immune System*

Storage

Store in a dry, cool place.

Brand IP Statement(s)

TRAACS(R) is a registered trademark of Albion Laboratories, Inc.

Seals/Symbols

IBG INDIANA BOTANIC GARDENS(R)

FDA Disclaimer Statement

*This statement has not been evaluated by the Food & Drug Administration. This product is not intended to diagnose, treat, cure or prevent any disease.

Formula

Zinc + A&C

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

See for yourself

Zinc + A & C by Indiana Botanic Gardens label

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

Zinc + A & C 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 + A & C by Indiana Botanic Gardens

These are the 7 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Lozenge(s) Dosage formLozenge 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.

Vitamin C

Interacts with
207 drugs
150 mg per serving Form: Ascorbic Acid

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for im...

Vitamin C monograph & interactions

Vitamin A

Interacts with
387 drugs
1000 IU per serving Form: Retinyl Palmitate

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplemen...

Vitamin A monograph & interactions

Bee Propolis

Interacts with
921 drugs
5 mg per serving

Propolis is a natural, resin-like substance made by bees that has antimicrobial and anti-inflammatory properties in lab studies. Early research sugges...

Bee Propolis monograph & interactions

Zinc

Interacts with
67 drugs
12 mg per serving Form: TRAACS Zinc Glycinate Chelate

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

Goldenseal

Interacts with
1,237 drugs
5 mg per serving

Goldenseal is a popular North American herb that contains berberine, a compound studied for antimicrobial effects. However, strong human evidence for...

Goldenseal monograph & interactions

Slippery Elm

Interacts with
2,022 drugs
5 mg per serving

Slippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated di...

Slippery Elm monograph & interactions

Echinacea purpurea

Interacts with
816 drugs
5 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 monograph & interactions

Other (inactive) ingredients: Natural Raspberry flavor, Cellulose, Citric Acid, Natural Pineapple flavor, Stearic Acid, Silica, Xanthan Gum, Natural Vanilla flavor, Magnesium Stearate, Beet powder, Acerola. These complete the product’s ingredient list but are not active constituents.

Interaction report

Zinc + A & C by Indiana Botanic Gardens Drug Interactions

Want to check YOUR meds against Zinc + A & C?

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
2,271Drugs
9 Major 2,261 Moderate 1 Minor

Ingredients driving the most interactions

Slippery Elm 2,022
Goldenseal 1,237
Bee Propolis 921
Echinacea purpurea 816
Vitamin A 387

Individual Drug Interactions

The ingredients in Zinc + A & C interact with 2,271 drugs. Click any drug to see the details.

7 of the 7 ingredients in Zinc + A & C interact with drugs. Each result below shows which ingredient is responsible. Slippery Elm Goldenseal Bee Propolis Echinacea purpurea Vitamin A Vitamin C Zinc

Each ingredient & the kinds of drugs it affects

For each ingredient in Zinc + A & C 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.

Slippery Elm1 drug type · 2,022 drugs

Oral Drugs

Theoretically, slippery elm may slow the absorption and reduce serum levels of oral drugs.
Slippery elm inner bark contains mucilage, which may interfere with the absorption of orally administered drugs.

Likelihood Possible Evidence D
Slippery Elm full monograph & interactions

Goldenseal16 drug types · 1,237 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, goldenseal might increase the risk of bleeding when used with anticoagulant or antiplatelet drugs.
Goldenseal contains berberine. In vitro and animal research shows that berberine can inhibit platelet aggregation. However, this effect has not been reported in humans.

Likelihood Possible Evidence D
Antidiabetes Drugs

Theoretically, goldenseal might increase the risk of hypoglycemia when used with antidiabetes drugs.
Goldenseal contains berberine. Clinical research shows that berberine can lower blood glucose levels. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, goldenseal might increase the risk of hypotension when taken with antihypertensive drugs.
Goldenseal contains berberine. Animal research shows that berberine can have hypotensive effects. Also, an analysis of clinical research shows that taking berberine in combination with amlodipine can lower systolic and diastolic blood pressure when compared with amlodipine alone. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D
Cns Depressants

Theoretically, goldenseal might increase the sedative effects of CNS depressants.
Goldenseal contains berberine. Animal research shows that berberine can have sedative effects. However, this effect has not been reported in humans.

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

Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2C9.
In vitro research shows that goldenseal root extract can modestly inhibit CYP2C9. This effect may be due to its alkaloid constituents, hydrastine and berberine. However, this effect has not been reported in humans.

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

Goldenseal might increase serum levels of drugs metabolized by CYP2D6.
Clinical and in vitro research shows that goldenseal can significantly inhibit CYP2D6 enzymes, potentially increasing levels of drugs metabolized by CYP2D6.

Likelihood Probable Evidence B
Cytochrome P450 2E1 (Cyp2E1) Substrates

Theoretically, goldenseal might increase serum levels of drugs metabolized by CYP2E1.
In vitro research shows that goldenseal root extract can inhibit the activity of CYP2E1. However, this effect has not been reported in humans.

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

Goldenseal might increase serum levels of drugs metabolized by CYP3A4.
Most clinical and in vitro research shows that goldenseal inhibits CYP3A4 enzyme activity and increases serum levels of CYP3A4 substrates, such as midazolam. However, in one small clinical study, goldenseal did not affect the levels of indinavir, a CYP3A4 substrate, in healthy volunteers. This is likely due to the fact that indinavir has a high oral bioavailability, making it an inadequate probe for CYP3A4 interactions and/or that it is primarily metabolized by hepatic CYP3A, while goldenseal has more potential to inhibit intestinal CYP3A enzyme activity. Both goldenseal extract and its isolated constituents berberine and hydrastine inhibit CYP3A, with hydrastine possibly having more inhibitory potential than berberine.

Likelihood Possible Evidence B
Dextromethorphan (Robitussin Dm, Others)

Theoretically, goldenseal might increase serum levels of dextromethorphan.
Goldenseal contains berberine. A small clinical study shows that berberine can inhibit cytochrome P450 2D6 (CYP2D6) activity and reduce the metabolism of dextromethorphan.

Likelihood Possible Evidence D
Digoxin (Lanoxin)

Goldenseal might increase serum levels of digoxin, although this effect is unlikely to be clinically significant.
Clinical research shows that goldenseal modestly increases digoxin peak levels by about 14% in healthy volunteers. However, goldenseal does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC). This suggests that goldenseal does not cause a clinically significant interaction with digoxin. Digoxin is a P-glycoprotein substrate. Some evidence suggests that goldenseal constituents might affect P-glycoprotein; however, it is unclear whether these constituents inhibit or induce P-glycoprotein.

Likelihood Probable Evidence B
Losartan (Cozaar)

Theoretically, goldenseal might decrease the conversion of losartan to its active form.
Goldenseal contains berberine. A small clinical study shows that berberine inhibits cytochrome P450 2C9 (CYP2C9) activity and reduces the metabolism of losartan. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D
Metformin (Glucophage)

Theoretically, goldenseal might reduce blood levels of metformin.
In vitro research shows that goldenseal extract decreases the bioavailability of metformin, likely by interfering with transport, intestinal permeability, or other processes involved in metformin absorption. It is unclear which, if any, of metformin's transporters are inhibited by goldenseal. Goldenseal does not appear to alter the clearance or half-life of metformin.

Likelihood Possible Evidence D
P-Glycoprotein Substrates

Theoretically, goldenseal might increase or decrease serum levels of P-glycoprotein (P-gp) substrates.
There is conflicting evidence about the effect of goldenseal on P-gp. In vitro research suggests that berberine, a constituent of goldenseal, modestly inhibits P-gp efflux. Other evidence suggests that berberine induces P-gp. In healthy volunteers, goldenseal modestly increases peak levels of the P-gp substrate digoxin by about 14%. However, it does not seem to affect other pharmacokinetic parameters such as area under the curve (AUC). This suggests that goldenseal is not a potent inhibitor of P-gp-mediated drug efflux. Until more is known, goldenseal should be used cautiously with P-gp substrates.

Likelihood Probable Evidence B
Pentobarbital (Nembutal)

Theoretically, goldenseal might increase the sedative effects of pentobarbital.
Animal research shows that berberine, a constituent of goldenseal, can prolong pentobarbital-induced sleeping time. However, this effect has not been reported with goldenseal.

Likelihood Possible Evidence D
Tacrolimus (Prograf)

Theoretically, goldenseal might increase serum levels of tacrolimus.
Goldenseal contains berberine. In a 16-year-old patient with idiopathic nephrotic syndrome who was being treated with tacrolimus 6.5 mg twice daily, intake of berberine 200 mg three times daily increased the blood concentration of tacrolimus from 8 to 22 ng/mL. Following a reduction of tacrolimus dosing to 3 mg daily, blood levels of tacrolimus decreased to 12 ng/mL.

Likelihood Possible Evidence D
Oseltamivir (Tamiflu)

Theoretically, goldenseal might reduce the therapeutic effects of oseltamivir by decreasing its conversion to its active form.
In vitro evidence suggests that goldenseal reduces the formation of the active compound from the prodrug oseltamivir. The mechanism of action and clinical relevance is unclear.

Likelihood Possible Evidence D
Goldenseal full monograph & interactions

Bee Propolis8 drug types · 921 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, propolis might increase the risk of bleeding when taken with antiplatelet or anticoagulant drugs.
In vitro research shows that propolis water extract and the propolis constituent, caffeic acid phenethyl ester, can inhibit platelet aggregation. Additionally, evidence from an animal model shows that taking propolis in addition to warfarin decreases INR, suggesting that propolis can decrease the effectiveness of warfarin.

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

Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP1A2.
In vitro research shows that propolis extract can inhibit CYP1A2. However, animal research shows that propolis extract does not significantly affect CYP1A2 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP1A2 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect. This effect has not been reported in humans.

Likelihood Possible Evidence D
Cytochrome P450 2C19 (Cyp2C19) Substrates

Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2C19.
In vitro research shows that propolis extract can inhibit CYP2C19. However, animal research shows that propolis extract does not significantly affect CYP2C19 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2C19 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect. This effect has not been reported in humans.

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

Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2C9.
In vitro research shows that propolis extract can inhibit CYP2C9. However, animal research shows that propolis extract does not significantly affect CYP2C9 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2C9 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect. This effect has not been reported in humans.

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

Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP2D6.
In vitro research shows that propolis extract can inhibit CYP2D6. However, animal research shows that propolis extract does not significantly affect CYP2D6 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that inhibit CYP2D6 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect. This effect has not been reported in humans.

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

Theoretically, propolis might increase levels of drugs metabolized by CYP2E1.
In vitro research shows that propolis can inhibit CYP2E1. This effect has not been reported in humans.

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

Theoretically, high doses of propolis might increase blood levels of drugs metabolized by CYP3A4.
Some in vitro research shows that propolis extract can inhibit CYP3A4; however, other in vitro research shows that propolis has no effect on CYP3A4 activity. Furthermore, animal research shows that propolis extract does not significantly affect CYP3A4 activity when administered to rats at doses up to 250 mg/kg. It is postulated that the constituents of propolis that might in inhibit CYP3A4 in vitro do not have significant effects in vivo due to low bioavailability and hepatic first-pass effect. This effect has not been reported in humans.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, propolis might decrease the effectiveness of warfarin.
Animal research shows that taking propolis in addition to warfarin decreases the international normalized ratio (INR). This effect has not been reported in humans.

Likelihood Possible Evidence D
Bee Propolis full monograph & interactions

Echinacea purpurea12 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 full monograph & interactions

Vitamin A4 drug types · 387 drugs

Retinoids

Concomitant use of retinoids with vitamin A supplements might produce supratherapeutic vitamin A levels.
Retinoids, which are vitamin A derivatives, could have additive toxic effects when taken with vitamin A supplements.

Likelihood Probable Evidence D
Hepatotoxic Drugs

Theoretically, taking high doses of vitamin A in combination with other potentially hepatotoxic drugs might increase the risk of liver disease.
The tolerable upper intake level (UL) is the highest level of intake that is likely to pose no risk of adverse effects. Doses of vitamin A above the UL can cause hepatotoxicity, ranging from elevated liver enzymes to liver failure.

Likelihood Possible Evidence C
Tetracycline Antibiotics

Theoretically, taking tetracycline antibiotics with high doses of vitamin A can increase the risk of pseudotumor cerebri.
Benign intracranial hypertension (pseudotumor cerebri) can occur with tetracyclines and with acute or chronic vitamin A toxicity. Case reports suggest that taking tetracyclines and vitamin A concurrently can increase the risk of this condition. Avoid high doses of vitamin A in people taking tetracyclines chronically.

Likelihood Possible Evidence D
Warfarin (Coumadin)

Theoretically, high doses of vitamin A could increase the risk of bleeding with warfarin.
Vitamin A toxicity is associated with hemorrhage and hypoprothrombinemia, possibly due to vitamin K antagonism. Advise patients taking warfarin to avoid doses of vitamin A above the tolerable upper intake level of 10,000 IU/day for adults.

Likelihood Possible Evidence D
Vitamin A full monograph & interactions

Vitamin C13 drug types · 207 drugs

Alkylating Agents

Theoretically, antioxidant effects of vitamin C might reduce the effectiveness of alkylating agents.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs that generate free radicals, such as cyclophosphamide, chlorambucil, carmustine, busulfan, and thiotepa. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effect, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Aluminum

Vitamin C can increase the amount of aluminum absorbed from aluminum compounds.
Research in animals and humans shows that vitamin C increases aluminum absorption, theoretically by chelating aluminum and keeping it in solution where it is available for absorption. In people with normal renal function, urinary excretion of aluminum will likely increase, making aluminum retention and toxicity unlikely. Patients with renal failure who take aluminum-containing compounds such as phosphate binders should avoid vitamin C supplements in doses above the recommended dietary allowances.

Likelihood Probable Evidence B
Antitumor Antibiotics

Theoretically, the antioxidant effects of vitamin C might reduce the effectiveness of antitumor antibiotics.
The use of antioxidants like vitamin C during chemotherapy is controversial. There is concern that antioxidants could reduce the activity of chemotherapy drugs which generate free radicals, such as doxorubicin. In contrast, some researchers theorize that antioxidants might make chemotherapy more effective by reducing oxidative stress that could interfere with apoptosis (cell death) of cancer cells. More evidence is needed to determine what effects, if any, antioxidants such as vitamin C have on chemotherapy.

Likelihood Possible Evidence D
Estrogens

Vitamin C might increase blood levels of estrogens.
Increases in plasma estrogen levels of up to 55% occur under some circumstances when vitamin C is taken concurrently with oral contraceptives or hormone replacement therapy, including topical products. It is suggested that vitamin C prevents oxidation of estrogen in the tissues, regenerates oxidized estrogen, and reduces sulfate conjugation of estrogen in the gut wall. When tissue levels of vitamin C are high, these processes are already maximized and supplemental vitamin C does not have any effect on estrogen levels. Increases in plasma estrogen levels may occur when patients who are deficient in vitamin C take supplements. Monitor these patients for estrogen-related side effects.

Likelihood Probable Evidence B
Fluphenazine (Prolixin)

Theoretically, vitamin C might decrease levels of fluphenazine.
In one patient there was a clinically significant decrease in fluphenazine levels when vitamin C (500 mg twice daily) was started. The mechanism is not known, and there is no further data to confirm this interaction.

Likelihood Possible Evidence D
Indinavir (Crixivan)

Vitamin C can modestly reduce indinavir levels.
One pharmacokinetic study shows that taking vitamin C 1 gram orally once daily along with indinavir 800 mg orally three times daily reduces the area under the concentration-time curve of indinavir by 14%. The mechanism of this interaction is unknown, but it is unlikely to be clinically significant in most patients. The effect of higher doses of vitamin C on indinavir levels is unknown.

Likelihood Probable Evidence B
Levothyroxine (Synthroid, Others)

Vitamin C can increase levothyroxine absorption.
Two clinical studies in adults with poorly controlled hypothyroidism show that swallowing levothyroxine with a glass of water containing vitamin C 500-1000 mg in solution reduces thyroid stimulating hormone (TSH) levels and increases thyroxine (T4) levels when compared with taking levothyroxine alone. This suggests that vitamin C increases the oral absorption of levothyroxine, possibly due to a reduction in pH.

Likelihood Probable Evidence B
Warfarin (Coumadin)

High-dose vitamin C might reduce the levels and effectiveness of warfarin.
Vitamin C in high doses may cause diarrhea and possibly reduce warfarin absorption. There are reports of two people who took up to 16 grams daily of vitamin C and had a reduction in prothrombin time. Lower doses of 5-10 grams daily can also reduce warfarin absorption. In many cases, this does not seem to be clinically significant. However, a case of warfarin resistance has been reported for a patient who took vitamin C 500 mg twice daily. Cessation of vitamin C supplementation resulted in a rapid increase in international normalized ratio (INR). Tell patients taking warfarin to avoid taking vitamin C in excessively high doses (greater than 10 grams daily). Lower doses may be safe, but the anticoagulation activity of warfarin should be monitored. Patients who are stabilized on warfarin while taking vitamin C should avoid adjusting vitamin C dosage to prevent the possibility of warfarin resistance.

Likelihood Possible Evidence D
Acetaminophen (Tylenol, Others)

High-dose vitamin C might slightly prolong the clearance of acetaminophen.
A small pharmacokinetic study in healthy volunteers shows that taking high-dose vitamin C (3 grams) 1.5 hours after taking acetaminophen 1 gram slightly increases the apparent half-life of acetaminophen from around 2.3 hours to 3.1 hours. Ascorbic acid competitively inhibits sulfate conjugation of acetaminophen. However, to compensate, elimination of acetaminophen glucuronide and unconjugated acetaminophen increases. This effect is not likely to be clinically significant.

Likelihood Probable Evidence B
Aspirin

Acidification of the urine by vitamin C might increase aspirin levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction is not clinically significant.

Likelihood Possible Evidence B
Choline Magnesium Trisalicylate (Trilisate)

Acidification of the urine by vitamin C might increase choline magnesium trisalicylate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams daily of vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Niacin

Vitamin C might decrease the beneficial effects of niacin on high-density lipoprotein (HDL) cholesterol levels.
A combination of niacin and simvastatin (Zocor) effectively raises HDL cholesterol levels in patients with coronary disease and low HDL levels. Clinical research shows that taking a combination of antioxidants (vitamin C, vitamin E, beta-carotene, and selenium) along with niacin and simvastatin (Zocor) attenuates this rise in HDL, specifically the HDL-2 and apolipoprotein A1 fractions, by more than 50% in patients with coronary disease. It is not known whether this adverse effect is due to a single antioxidant such as vitamin C, or to the combination. It also is not known whether it will occur in other patient populations.

Likelihood Possible Evidence A
Salsalate (Disalcid)

Acidification of the urine by vitamin C might increase salsalate levels.
It has been suggested that acidification of the urine by vitamin C could increase reabsorption of salicylates by the renal tubules, and increase plasma salicylate levels. However, short-term use of up to 6 grams/day vitamin C does not seem to affect urinary pH or salicylate excretion, suggesting this interaction probably is not clinically significant.

Likelihood Possible Evidence B
Vitamin C 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
The maker

Brand information

Manufacturer and brand details for Zinc + A & C, from the product label.

Indiana Botanic Gardens

See all Indiana Botanic Gardens products
Name
Indiana Botanic Gardens, Inc.
Street Address
3401 W. 37th Ave.
City
Hobart
State
IN
ZipCode
46342
Pharmacist Counseling Corner

Zinc + A & C by Indiana Botanic Gardens: Common Questions

Does Zinc + A & C by Indiana Botanic Gardens interact with any medications?
Yes. Based on its ingredients, Zinc + A & C has a known interaction with 2,271 medications, including 9 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Zinc + A & C contains 7 active ingredients, and an interaction can come from any of them. We check every ingredient, combine the results into one list per medication, and show which ingredient and mechanism is responsible.
Where does this information come from?
The product label data comes from the NIH Dietary Supplement Label Database (DSLD); the interaction data is built on the Natural Medicines database and reviewed by HelloPharmacist pharmacists.
Does this lozenge work for colds or the flu?
The evidence in our data doesn't establish this product as effective for colds or flu. Echinacea and vitamin C are traditionally used for immune support, but we don't hold data showing this exact combination works for those conditions. Talk with your pharmacist about what the research actually shows for each ingredient separately.
Is it safe for me to take this while pregnant?
It depends on which ingredients. Vitamin C at normal amounts is likely safe in pregnancy; vitamin A at recommended amounts is likely safe, but high doses are possibly unsafe and may cause birth defects. We have no safety data on file for bee propolis, goldenseal, slippery elm, or echinacea in pregnancy. Talk with your doctor or pharmacist before using this product if you're pregnant.
Can I breastfeed while taking this?
Vitamin C and vitamin A at recommended doses are likely safe while breastfeeding. Bee propolis and echinacea should be avoided while breastfeeding because we don't have enough safety information. Goldenseal contains berberine, which may pass to your infant and cause harm, so it should also be avoided. Ask your doctor or pharmacist before using this product if you're nursing.
What's in this lozenge?
It has seven active ingredients: vitamin C, vitamin A, bee propolis, zinc, goldenseal, slippery elm, and echinacea purpurea. It also contains fillers and flavor agents like cellulose, citric acid, natural flavors, stearic acid, silica, and xanthan gum.
Can this interact with my birth control?
Yes. Vitamin C in this lozenge can increase blood levels of estrogen in oral contraceptives—potentially by up to 55% in some cases. This is a Moderate interaction. If you use birth control, check with your pharmacist before starting this product, and consider having your provider monitor you.
I'm taking an antibiotic. Is it safe to use this?
It depends on which antibiotic. Zinc in this product can reduce absorption of quinolone antibiotics, tetracyclines, and cephalexin if taken at the same time. If you're on one of these, take the antibiotic at least 2 hours before or several hours after this lozenge. Check with your pharmacist about your specific antibiotic.

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.

Zinc + A & C label
Go deeper

The Full Monographs Behind Zinc + A & C’s Ingredients

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

Herb & supplement monograph

Vitamin C

Interacts with 207 drugs

Vitamin C (ascorbic acid) is an essential nutrient your body needs but cannot make, so you must get it from food or supplements. It's important for immune function, collagen, and acts as an...

Read the full Vitamin C monograph → Herb & supplement monograph

Vitamin A

Interacts with 387 drugs

Vitamin A is an essential nutrient important for vision, skin, immune function, and growth. Most people get enough from a balanced diet, and supplements are mainly useful for correcting a tr...

Read the full Vitamin A monograph → Herb & supplement monograph

Propolis

Interacts with 921 drugs

Propolis is a natural, resin-like substance made by bees that has antimicrobial and anti-inflammatory properties in lab studies. Early research suggests it may help with cold sores, mouth so...

Read the full Propolis 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

Goldenseal

Interacts with 1,237 drugs

Goldenseal is a popular North American herb that contains berberine, a compound studied for antimicrobial effects. However, strong human evidence for its many traditional uses is largely lac...

Read the full Goldenseal monograph → Herb & supplement monograph

Slippery Elm

Interacts with 2,022 drugs

Slippery elm is a traditional herbal remedy made from the inner bark of a North American elm tree, used mainly to soothe sore throats and irritated digestive tracts. Its mucilage can coat an...

Read the full Slippery Elm 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 →
Sources

Sources & How We Checked

Zinc + A & C'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 279 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.

Vitamin C 51 references
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DISCLAIMER: Currently this does not check for drug-drug interactions. This is not an all-inclusive comprehensive list of potential interactions and is for informational purposes only. Not all interactions are known or well-reported in the scientific literature, and new interactions are continually being reported. Input is needed from a qualified healthcare provider including a pharmacist before starting any therapy. Application of clinical judgment is necessary.

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