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

NAC 500 Ingredients & Drug Interactions

by ProCaps Laboratories

NAC 500 label
See full label image
Capsule Category: Other Combinations
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 NAC 500 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

NAC 500 is a dietary supplement by ProCaps Laboratories with 2 active ingredients. Its ingredients are commonly taken for thinning mucus in lung conditions, acetaminophen (tylenol) overdose treatment, antioxidant and glutathione support.Based on those ingredients, 461 medications have a known interaction with it, the most serious rated major. The ingredients most likely to interact are N-Acetyl Cysteine, Vitamin C. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against NAC 500 by ProCaps Laboratories

Ask about any prescription or over-the-counter medication and we check it for interactions with NAC 500 by ProCaps Laboratories — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of NAC 500 by ProCaps Laboratories

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 Aug 27, 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 2 of its 2 active ingredients.
  • No proprietary blends here — you can verify the dose of every single component.

NAC 500 contains two active ingredients: N-acetyl cysteine (the primary component, at 500 mg per capsule) and vitamin C. The capsule itself is made of gelatin.

N-acetyl cysteine is a compound that helps break down and thin mucus, making it useful for respiratory and other conditions. Vitamin C is an antioxidant nutrient that supports immune function and collagen formation.

Together they're combined in a single capsule for convenience.

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: detoxifying antioxidant and glutathione precursor.
  • We looked for evidence on: Acetaminophen poisoning, Acute bronchitis, Acute respiratory distress syndrome (ARDS), Asthma, Bronchiectasis, Bronchitis — and 4 related terms.
  • The strongest evidence on file: N-acetyl Cysteine (nac) is rated "Effective" for Acetaminophen poisoning (Natural Medicines).
  • Also on file: N-acetyl Cysteine (nac) is rated "Possibly Effective" for Bronchitis, Chronic obstructive pulmonary disease (COPD).
  • Also on file: Vitamin C is rated "Possibly Ineffective" for Acute bronchitis.

N-acetyl cysteine is effective for acetaminophen (Tylenol) poisoning, atelectasis (a lung condition where air sacs collapse), bronchial diagnostic studies, and tracheostomy care. It's possibly effective for bronchitis.

Vitamin C is effective for vitamin C deficiency. It's possibly effective for anemia of chronic disease, atrial fibrillation, cataracts, and exercise-induced respiratory infections.

The evidence we hold does not establish effectiveness for other uses.

The evidence, ingredient by ingredient N-acetyl Cysteine (nac) Vitamin C

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 2 of the 2 matched ingredients.
  • Pregnancy & breastfeeding safety ratings cover 2 of 2.
  • General safety write-ups exist for 2 of 2.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

N-acetyl cysteine is generally well tolerated at typical doses, though you should talk to your healthcare provider before use. Most side effects occur only at very high doses (over 9 grams in a single dose or more than 30 grams daily).

When taken orally at normal doses, the most common side effects are diarrhea, dry mouth, heartburn, nausea, vomiting, and loss of appetite. Joint pain was reported in more than 15% of patients in one clinical trial.

Safety during pregnancy has not been well studied; discuss this with your doctor. Vitamin C is well tolerated at normal dietary and supplement doses.

Very high doses can cause abdominal cramps, heartburn, diarrhea, nausea, vomiting, and kidney stones in people prone to them—side effects become more likely above 2 grams daily. For pregnancy and breastfeeding, normal amounts from food and prenatal vitamins are fine, but avoid high-dose supplements unless your doctor advises otherwise.

Side effects, ingredient by ingredient N-acetyl Cysteine (nac) Vitamin C

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?
  • 2 of the 2 matched ingredients can interact with medications — Vitamin C, N-acetyl Cysteine (nac).
  • The most serious interaction on file is rated Major.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs; cancer treatments.
  • For scale: 461 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 NAC 500, double-check with your doctor or pharmacist if you take nitroglycerin (Major severity), or any blood pressure medications, blood thinners, antimalarial drugs, chemotherapy, estrogen-based birth control or hormone therapy, warfarin, fluphenazine, indinavir, levothyroxine, or antitumor antibiotics (all Moderate severity). Also mention activated charcoal if you use it.

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. Major medication interactions have been identified, and safety information is well characterized.

NAC 500 may be worth considering if you have a respiratory condition like bronchitis or need it for acetaminophen poisoning treatment under medical supervision. If you take any heart medications (especially nitroglycerin), blood pressure drugs, blood thinners, thyroid medication, antipsychotics, HIV drugs, chemotherapy, or birth control, you should absolutely check with your doctor or pharmacist before starting this product.

Talk it over with your healthcare provider to make sure it fits your situation.

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

Assessment coverage: 2 of 2 active ingredients matched to our full ingredient reviews (monographs). Based on the product label dated Oct 24, 2022.

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 NAC 500, straight from the product label.

Brand ProCaps Laboratories
Barcode (UPC) 385999
Net contents 360 Easy-To-Swallow Capsule(s)
Market status On market
Date entered into DSLD Oct 24, 2022
DSLD ID 275277
Product type Other Combinations
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free, Sugar Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for NAC 500 by ProCaps Laboratories, 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
360
UPC/BARCODE
385999
IngredientAmount% DV
N-Acetyl Cysteine500 mg--
Vitamin C30 mg33%

Other ingredients: Gelatin Capsule

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 Consume one or more capsules daily or as recommended by your physician. As with any dietary supplement, this product is most effective as part of a healthy diet and active lifestyle. For questions about the use of this product call 800.332.7799.

General Statements

For over 40 years Unsurpassed Purity, Quality and Efficacy 100% solar production Zero carbon footprint Andrew Lessman, Founder Questions? Reorders? 800.800.1200 www.ProCapslabs.com HSN www.HSN.com 800.944.9999 www.QVC.com 800.345.1515

100% solar

Formulation

Detoxifying anti-oxidant Glutathione precursor

Contains no additives or common allergens Contains no milk, soy, yeast, wheat, gluten, sodium, salt, sugar, fat, cholesterol, color, preservative, common allergens, genetically modified (GMO) ingredients or manufacturing additives.

FDA Statement of Identity

Dietary Supplement

Formula

Andrew Lessman's NAC 500 delivers 500 mg of n-acetyl cysteine (NAC), an essential glutathione precursor and detoxifying antioxidant that is a uniquely active form of the conditionally essential amino acid cysteine. It is the sulfur in cysteine's "thiol" (sulfhydryl) group that imparts NAC's unique properties, including its critical role as a building block of glutathione - our body's most powerful, internally-produced protective compound. NAC offers important protection to the brain, heart and lungs, but because of its unique detoxifying role, NAC provides targeted protection to the hard working cells of the liver and kidneys making it a sensible part of any internal cleanser detoxification program. Unfortunately, NAC is not readily available from the diet and it cannot be readily produced by the body, so supplementation is a straightforward way of promoting its protective benefits.

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.

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

See for yourself

NAC 500 by ProCaps Laboratories label

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

NAC 500 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 NAC 500 by ProCaps Laboratories

These are the 2 active ingredients this product is made of. Select any to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container360 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.

N-Acetyl Cysteine

Interacts with
294 drugs
500 mg per serving

N-acetyl cysteine (NAC) is a supplement form of the amino acid cysteine and a building block for the antioxidant glutathione. It has well-established...

N-Acetyl Cysteine monograph & interactions

Vitamin C

Interacts with
207 drugs
30 mg per serving Form: Ascorbyl Palmitate, Calcium Ascorbate

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

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

Interaction report

NAC 500 by ProCaps Laboratories Drug Interactions

Want to check YOUR meds against NAC 500?

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
461Drugs
1 Major 388 Moderate 72 Minor

Ingredients driving the most interactions

N-Acetyl Cysteine 294
Vitamin C 207

Individual Drug Interactions

The ingredients in NAC 500 interact with 461 drugs. Click any drug to see the details.

2 of the 2 ingredients in NAC 500 interact with drugs. Each result below shows which ingredient is responsible. N-Acetyl Cysteine Vitamin C

Each ingredient & the kinds of drugs it affects

For each ingredient in NAC 500 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.

N-Acetyl Cysteine5 drug types · 294 drugs

Nitroglycerin

N-acetyl cysteine can increase the risk for hypotension and headaches when taken with intravenous or transdermal nitroglycerin.
Clinical research shows that concomitant administration of N-acetyl cysteine and intravenous or transdermal nitroglycerin can cause severe hypotension and intolerable headaches. Furthermore, in vitro research suggests that N-acetyl cysteine increases the anticoagulant activity of nitroglycerin.

Likelihood Probable Evidence B
Activated Charcoal

N-acetyl cysteine might reduce the effects of activated charcoal, while activated charcoal might reduce the absorption of N-acetyl cysteine.
N-acetyl cysteine appears to reduce the capacity of activated charcoal to adsorb acetaminophen and salicylic acid. Conversely, although clinical research suggests that although activated charcoal can reduce the absorption of N-acetyl cysteine by up to 40%, it does not seem to reduce its clinical effects. Other clinical evidence suggests that activated charcoal does not affect the absorption of N-acetyl cysteine.

Likelihood Possible Evidence D
Anticoagulant/Antiplatelet Drugs

Theoretically, N-acetyl cysteine might increase the risk of bleeding when taken with anticoagulant or antiplatelet drugs.
Clinical research suggests that intravenous N-acetyl cysteine decreases prothrombin time, prolongs coagulation time, decreases platelet aggregation, and increases blood loss in surgical patients. Furthermore, in vitro research suggests that N-acetyl cysteine increases the anticoagulant activity of nitroglycerin.

Likelihood Possible Evidence D
Antihypertensive Drugs

Theoretically, N-acetyl cysteine might increase the risk of hypotension when taken with antihypertensive drugs.
Animal research suggests that N-acetyl cysteine potentiates the hypotensive effects of the angiotensin-converting enzyme inhibitors (ACEIs) captopril and enalaprilat. Theoretically, combining N-acetyl cysteine with other antihypertensive drugs might increase the risk of hypotension.

Likelihood Possible Evidence D
Chloroquine (Aralen)

Theoretically, N-acetyl cysteine might interfere with the antimalarial effects of chloroquine.
Animal research suggests that N-acetyl cysteine might reduce the antimalarial effects of chloroquine by increasing cellular levels of glutathione.

Likelihood Possible Evidence D
N-Acetyl Cysteine 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
The maker

Brand information

Manufacturer and brand details for NAC 500, from the product label.

ProCaps Laboratories

See all ProCaps Laboratories products
Name
ProCaps Laboratories
City
Henderson
State
NV
ZipCode
89011
Phone Number
800.800.1200
Web Address
ProCapsLabs.com
Pharmacist Counseling Corner

NAC 500 by ProCaps Laboratories: Common Questions

Does NAC 500 by ProCaps Laboratories interact with any medications?
Yes. Based on its ingredients, NAC 500 has a known interaction with 461 medications, including 1 rated major. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
NAC 500 contains 2 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 NAC 500 safe to take while pregnant?
N-acetyl cysteine is rated possibly safe in pregnancy, but safety has not been well studied. Vitamin C in normal amounts from food and prenatal vitamins is considered likely safe during pregnancy; however, high-dose supplements are not advised unless your doctor recommends them. Talk with your doctor or pharmacist before taking this product while pregnant to weigh what's best for you and your baby.
What are the most common side effects?
At typical doses, N-acetyl cysteine most commonly causes diarrhea, dry mouth, heartburn, nausea, vomiting, and loss of appetite. Vitamin C at normal supplement doses is generally well tolerated; side effects like abdominal cramps and diarrhea become more likely at very high doses over 2 grams daily. Joint pain was reported in more than 15% of patients taking oral N-acetyl cysteine in one study.
Will this help my chronic cough or bronchitis?
N-acetyl cysteine is possibly effective for bronchitis based on the evidence we hold. If you're considering it for a cough or bronchitis, talk with your doctor about whether it's a good fit for your situation and what dose might help.
Can I take this if I'm on birth control?
The vitamin C in this product may increase estrogen levels when taken with birth control pills or hormone therapy, which could affect how well your birth control works. Check with your doctor or pharmacist before taking NAC 500 if you use oral contraceptives or hormone replacement therapy.
Is this product safe to take with blood thinners like warfarin?
Both ingredients in this product can interact with blood thinners and antiplatelet drugs. N-acetyl cysteine may increase bleeding risk, and high-dose vitamin C may reduce warfarin's effectiveness. Do not take this product with blood thinners without checking with your doctor or pharmacist first.
What does N-acetyl cysteine do?
N-acetyl cysteine helps break down and thin mucus, making it useful for respiratory conditions. It's also used to treat acetaminophen overdose. The evidence shows it's effective for acetaminophen poisoning, certain lung conditions, and possibly effective for bronchitis.

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.

NAC 500 label
Go deeper

The Full Monographs Behind NAC 500’s Ingredients

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

Herb & supplement monograph

N-acetyl Cysteine (nac)

Interacts with 294 drugs

N-acetyl cysteine (NAC) is a supplement form of the amino acid cysteine and a building block for the antioxidant glutathione. It has well-established prescription uses for acetaminophen over...

Read the full N-acetyl Cysteine (nac) monograph → 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 →
Sources

Sources & How We Checked

NAC 500'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 137 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.

N-acetyl Cysteine (nac) 86 references
  1. Ellenhorn MJ, et al. Ellenhorn's Medical Toxicology: Diagnoses and Treatment of Human Poisoning. 2nd ed. Baltimore, MD: Williams & Wilkins, 1997.
  2. Jepsen S, Hansen AB. The influence of N-acetylcysteine on the measurement of prothrombin time and activated partial thromboplastin time in healthy subjects. Scand J Clin Lab Invest 1994;54:543-7. PubMed
  3. van Zandwijk N, Dalesio O, Pastorino U, et al. EUROSCAN, a randomized trial of vitamin A and N-acetylcysteine in patients with head and neck cancer or lung cancer. For the European Organization for Research and Treatment of Cancer Head and Neck and Lung C DOI
  4. Horowitz RS, Dart RC, Jarvie DR, et al. Placental transfer of N-acetylcysteine following human maternal acetaminophen toxicity. J Toxicol Clin Toxicol 1997;35:447-51.
  5. Bailey B, McGuigan MA. Management of anaphylactoid reactions to intravenous N-acetylcysteine. Ann Emerg Med 1998;31:710-5. PubMed
  6. Spiller HA, Krenzelok EP, Grande GA, et al. A prospective evaluation of the effect of activated charcoal before oral N-acetylcysteine in acetaminophen overdose. Ann Emerg Med 1994;23:519-23. PubMed
  7. Ardissino D, Merlini PA, Savonitto S, et al. Effect of transdermal nitroglycerin or N-acetylcysteine, or both, in the long-term treatment of unstable angina pectoris. J Am Coll Cardiol 1997;29:941-7. PubMed
  8. Horowitz JD, Henry CA, Syrjanen ML, et al. Nitroglycerine/N-acetylcysteine in the management of unstable angina pectoris. Eur Heart J 1988;9:95-100. PubMed
  9. Louwerse ES, Weverling GJ, Bossuyt PM, et al. Randomized, double-blind, controlled trial of acetylcysteine in amyotrophic lateral sclerosis. Arch Neurol 1995;52:559-64. PubMed
  10. Wiklund O, Fager G, Andersson A, et al. N-acetylcysteine treatment lowers plasma homocysteine but not serum lipoprotein(a) levels. Atherosclerosis 1996;119:99-106. PubMed
  11. De Flora S, Grassi C, Carati L. Attenuation of influenza-like symptomatology and improvement of cell-mediated immunity with long-term N-acetylcysteine treatment. Eur Respir J 1997;10:1535-41. PubMed
  12. Iversen HK. N-acetylcysteine enhances nitroglycerin-induced headache and cranial arterial responses. Clin Pharmacol Ther 1992;52:125-33. PubMed
  13. Behr J, Maier K, Degenkolb B, et al. Antioxidative and clinical effects of high-dose N-acetylcysteine in fibrosing alveolitis. Adjunctive therapy to maintenance immunosuppression. Am J Respir Crit Care Med 1997;156:1897-901.
  14. Tenenbein PK, Sitar DS, Tenenbein M. Interaction between N-acetylcysteine and activated charcoal: implications for the treatment of acetaminophen poisoning. Pharmacotherapy 2001;21:1331-6.
  15. Arstall MA, Yang J, Stafford I, et al. N-acetylcysteine in combination with nitroglycerin and streptokinase for the treatment of evolving acute myocardial infarction. Safety and biochemical effects. Circulation 1995;92:2855-62.
  16. Estensen RD, Levy M, Klopp SJ, et al. N-acetylcysteine suppression of the proliferative index in the colon of patients with previous adenomatous colonic polyps. Cancer Lett 1999;147:109-14. PubMed
  17. Pela R, Calcagni AM, Subiaco S, et al. N-acetylcysteine reduces the exacerbation rate in patients with moderate to severe COPD. Respiration 1999;66:495-500.. PubMed
  18. Oldemeyer JB, Biddle WP, Wurdeman RL, et al. Acetylcysteine in the prevention of contrast-induced nephropathy after coronary angiography. Am Heart J 2003;146:E23. . PubMed
  19. Ekins BR, Ford DC, Thompson MI, et al. The effect of activated charcoal on N-acetylcysteine absorption in normal subjects. Am J Emerg Med. 1987;5(6):483-7. PubMed
  20. Chamberlain JM, Gorman RL, Oderda GM, Klein-Schwartz W, Klein BL. Use of activated charcoal in a simulated poisoning with acetaminophen: a new loading dose for N-acetylcysteine? Ann Emerg Med. 1993;22(9):1398-402. PubMed
  21. Renzi FP, Donovan JW, Martin TG, Morgan L, Harrison EF. Concomitant use of activated charcoal and N-acetylcysteine. Ann Emerg Med. 1985;14(6):568-72. DOI
  22. North DS, Peterson RG, Krenzelok EP. Effect of activated charcoal administration on acetylcysteine serum levels in humans. Am J Hosp Pharm. 1981;38(7):1022-4. DOI
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See these in context on the N-acetyl Cysteine (nac) monograph →

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

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