Niacinamide Ingredients & Drug Interactions
by GNC Mega Men
What is this page for?
First and foremost: checking Niacinamide 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
Niacinamide is a dietary supplement by GNC Mega Men with 1 active ingredient. Its ingredients are commonly taken for high cholesterol, vitamin b3 deficiency (pellagra), heart health support.Based on those ingredients, 727 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Niacin. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.
Check Your Meds Against Niacinamide by GNC Mega Men
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AI summaries are generated from our interaction database for education only — always confirm with your pharmacist. How we use AI
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HelloPharmacist Scorecard of Niacinamide by GNC Mega Men
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.
What’s inside
Full disclosure
GNC Mega Men Niacinamide is a single-ingredient supplement containing niacin (also called vitamin B3). Niacin is an essential nutrient involved in energy production and metabolism.
This product also contains inactive ingredients—dicalcium phosphate, cellulose, stearic acid, magnesium stearate, and whole brown rice powder—which are fillers and binders that hold the tablet together.
Does it work?
Strong evidence
Niacin is likely effective for treating pellagra, a vitamin B3 deficiency disease. It's also possibly effective for improving cholesterol and triglyceride levels in people with HIV/AIDS-related dyslipidemia and for metabolic syndrome.
If you're taking this for general health or energy, the evidence in our data doesn't establish that use.
How safe is it?
Well-documented data
Normal dietary amounts of niacin from food are safe, and this product is generally well tolerated at prescription doses when monitored by a healthcare provider. However, high supplemental doses—like those in some multivitamins—can cause flushing (a very common side effect, affecting up to 70% of people taking larger doses), stomach upset, and liver problems.
Rare serious side effects include liver toxicity, muscle breakdown, low platelet counts, and vision changes. Flushing typically goes away within two weeks, and stomach issues are often reduced by taking niacin with food or an antacid.
For pregnancy, amounts from food and standard prenatal vitamins are fine, but high-dose niacin should be avoided unless prescribed by your doctor. During breastfeeding, normal dietary intake is safe, but avoid high-dose supplements unless directed.
Talk with your doctor or pharmacist about whether this product is right for you before starting.
Meds to double-check
Moderate interaction found
Before taking GNC Mega Men Niacinamide, double-check with your doctor or pharmacist if you take blood pressure medications, blood thinners or antiplatelet drugs, diabetes medications, cholesterol-lowering statins, drugs that can affect the liver, or gout treatments like allopurinol or probenecid. All of these have moderate-severity interactions with niacin documented in our data.
The bottom line
Scorecard at a glanceFully disclosed formula with strong clinical evidence behind its ingredients' uses. Moderate medication interactions have been identified, and safety information is well characterized.
This niacin supplement is effective for pellagra and possibly helpful for certain cholesterol and metabolic issues, but it's important to know it interacts with many common medications—especially blood pressure drugs, blood thinners, diabetes medications, and statins. The most serious concern is with blood pressure control.
If you take any prescription medications, check with your doctor or pharmacist before adding this to your routine.
Educational only — not medical advice; always confirm with your pharmacist. Our editorial policy · How we use AI
Assessment coverage: 1 of 1 active ingredient matched to our full ingredient reviews (monographs). Based on the product label dated Nov 21, 2016.
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
General information
Key facts about Niacinamide, straight from the product label.
| Brand | GNC Mega Men |
|---|---|
| Net contents | 30 Pack(s) |
| Market status | On market |
| Date entered into DSLD | Nov 21, 2016 |
| DSLD ID | 66746 |
| Product type | Vitamin |
| Supplement form | Tablet Or Pill |
| Dietary claims / uses | Nutrient, All Other, Structure/Function |
| Intended target group(s) | Adult Male (18-50 Years), Gluten Free, Dairy Free |
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 Niacinamide by GNC Mega Men, sourced from the NIH Dietary Supplement Label Database.
Supplement Facts
| Ingredient | Amount | % DV |
|---|---|---|
| Niacin | 100 mg | 500% |
Other ingredients: Dicalcium Phosphate, Cellulose, Stearic Acid, Magnesium Stearate, whole Brown Rice powder
Tap any ingredient to jump to its full detail below.
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.
General
CODE 209911 GQG
Suggested/Recommended/Usage/Directions
Directions: As a dietary supplement, take the contents of one pack daily with food.
General Statements
Each pack contains:
Potencies verified by procedure #5103. Conforms to USP <2091> for weight. Meets USO <2040> disintegration. Actual size
In a randomized, double-blind, placebo-controlled study of 112 healthy volunteers, subjects taking the GNC vitamin and mineral blend in this product for six weeks experienced statistically significant improvements in markers of B vitamin and antioxidant status, as well as improvements in SF-36 Vitality and Mental Health scores compared to those taking a placebo.
Physician endorsed This product is endorsed by the GNC Medical Advisory Board. This team of esteemed physicians utilizes their extensive medical knowledge and experience to aid in the creation of GNC premium products, helping you achieve optimal health through comprehensive nutritional support so you can live your best life!
Achieve your daily nutritional goal with customized ingredients plus multivitamins that have more antioxidant power than ever, contain over 30 clinically studied ingredients - and are smaller and easier to swallow.
Formula
Niacinamide
- Healthy cholesterol levels Packed with phytosterols and fish oil to support healthy cholesterol levels and niacin to support a healthy blood lipid profile.
Precautions
Warning: Consult your physician prior to using this product if you are pregnant, nursing, taking medication, or have a medical condition.
Discontinue use two weeks prior to surgery.
Keep out of reach of children.
Formulation
No Artificial Colors, no Artificial Flavors, no Wheat, Gluten free, no Dairy, Yeast free.
Seals/Symbols
Gf Gluten free
Physician endorsed
Storage
Store in a cool, dry place.
FDA Statement of Identity
Dietary Supplement
Brand IP Statement(s)
Vitapak program with clinically studied multivitamin
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.
Niacinamide by GNC Mega Men label
The label scan from the NIH Dietary Supplement Label Database. Tap to enlarge.
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)The Ingredients in Niacinamide by GNC Mega Men
This is the 1 active ingredient this product is made of. Select it to open its full monograph.
Serving size1 White Tablet(s) Dosage formTablet Or Pill Amounts shown are per serving.
Niacin
Interacts with727 drugs
Niacin (vitamin B3) is an essential nutrient your body needs for energy and metabolism, and deficiency is uncommon in most developed countries. Prescr...
Niacin monograph & interactionsOther (inactive) ingredients: Dicalcium Phosphate, Cellulose, Stearic Acid, Magnesium Stearate, Whole Brown Rice powder. These complete the product’s ingredient list but are not active constituents.
Niacinamide by GNC Mega Men Drug Interactions
HelloPharmacist Interaction Report
GNC Mega Men Niacinamide contains niacin, which has documented moderate-severity interactions with multiple medication types.
The most serious concern is with blood pressure medications (antihypertensives)—niacin can widen blood vessels and theoretically increase the risk of dangerously low blood pressure when combined with these drugs.
Read the full breakdown — every affected drug type, severity by severity
Niacin also interacts moderately with blood thinners and clot-prevention drugs (anticoagulants and antiplatelets), drugs that lower blood sugar (antidiabetes medications), cholesterol-lowering statins, liver-toxic drugs, and gout medications like allopurinol and probenecid. With statins, there's a theoretical concern about muscle breakdown; with blood sugar drugs, niacin may raise glucose levels and reduce their effectiveness; with gout drugs, niacin can interfere with uric acid control.
Bile acid sequestrants (cholesterol binders) can significantly reduce how much niacin your body absorbs—if you take both, space them 4 to 6 hours apart.
Altogether, these interactions span 728 individual medications. Before starting this product, check your exact medications with your doctor or pharmacist, especially if you take any blood pressure medication, blood thinner, diabetes drug, statin, or gout treatment.
Check your own medications below · Editorial policy · How we use AI
Want to check YOUR meds against Niacinamide?
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 checkerIngredients driving the most interactions
Individual Drug Interactions
The ingredients in Niacinamide interact with 727 drugs. Click any drug to see the details.
1 of the 1 ingredient in Niacinamide interact with drugs. Each result below shows which ingredient is responsible. Niacin
6-mercaptopurinePurinethol
How 6-mercaptopurine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + 6-mercaptopurine interactionAbacavir Sulfate, Dolutegravir, LamivudineTriumeq
How Abacavir Sulfate, Dolutegravir, Lamivudine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Abacavir Sulfate, Dolutegravir, Lamivudine interactionAbacavir, LamivudineEpzicom
How Abacavir, Lamivudine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Abacavir, Lamivudine interactionAbciximabReoPro
How Abciximab interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Read the full Niacin + Abciximab interactionAbiraterone
How Abiraterone interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Abiraterone interactionAbiraterone AcetateYonsa, Zytiga
How Abiraterone Acetate interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Abiraterone Acetate interactionAbrocitinibCibinqo
How Abrocitinib interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Read the full Niacin + Abrocitinib interactionAcarboseGlucobay, Prandase, Precose
How Acarbose interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAntidiabetes Drugs, Hepatotoxic Drugs Moderate
Interaction Summary
Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Read the full Niacin + Acarbose interactionAcebutololRhotral, Sectral
How Acebutolol interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAntihypertensive Drugs, Hepatotoxic Drugs Moderate
Interaction Summary
Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
Read the full Niacin + Acebutolol interactionAcenocoumarolSintrom
How Acenocoumarol interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAnticoagulant/antiplatelet Drugs Moderate
Interaction Summary
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Read the full Niacin + Acenocoumarol interactionAcetaminophenChildren's Tylenol, Children's Tylenol Meltaways, Tylenol, Tylenol Ex Strength
How Acetaminophen interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen interactionAcetaminophen, AspirinGemnisyn
How Acetaminophen, Aspirin interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAnticoagulant/antiplatelet Drugs, Aspirin +1 Moderate
Interaction Summary
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Read the full Niacin + Acetaminophen, Aspirin interactionAcetaminophen, Aspirin, CaffeineExcedrin, Excedrin Extra Strength, Excedrin Migraine
How Acetaminophen, Aspirin, Caffeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinAnticoagulant/antiplatelet Drugs, Hepatotoxic Drugs +1 Moderate
Interaction Summary
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Read the full Niacin + Acetaminophen, Aspirin, Caffeine interactionAcetaminophen, Brompheniramine, PhenylpropanolamineDimetapp Cold and Flu
How Acetaminophen, Brompheniramine, Phenylpropanolamine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Brompheniramine, Phenylpropanolamine interactionAcetaminophen, ButalbitalAxocet, Bancap, Bucet, Butex Forte, Esgic CF, Orbivan CF +5 more
How Acetaminophen, Butalbital interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Butalbital interactionAcetaminophen, Butalbital, CaffeineEsgic, Esgic Plus, Fiogesic, Fioricet, Repan, Tecnal +1 more
How Acetaminophen, Butalbital, Caffeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Butalbital, Caffeine interactionAcetaminophen, Butalbital, Caffeine, CodeineEsgic with Codeine, Fioricet w/ Codeine
How Acetaminophen, Butalbital, Caffeine, Codeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Butalbital, Caffeine, Codeine interactionAcetaminophen, Butalbital, CodeineBancap w/ Codeine
How Acetaminophen, Butalbital, Codeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Butalbital, Codeine interactionAcetaminophen, Butalbital, Codeine PhosphatePhrenilin #3
How Acetaminophen, Butalbital, Codeine Phosphate interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Butalbital, Codeine Phosphate interactionAcetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, PhenylephrineHycomine Compound
How Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Chlorpheniramine, Hydrocodone, Phenylephrine interactionAcetaminophen, Caffeine, CodeineGesic C15, Gesic C30, Gesic C8, Lenoltec 1, Lenoltec 2, Lenoltec 3 +1 more
How Acetaminophen, Caffeine, Codeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Codeine interactionAcetaminophen, Caffeine, Codeine, SalicylamideCodalan No.1, Codalan No.2, Codalan No.3
How Acetaminophen, Caffeine, Codeine, Salicylamide interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Codeine, Salicylamide interactionAcetaminophen, Caffeine, DihydrocodeineDHC Plus, Panlor DC, Panlor SS
How Acetaminophen, Caffeine, Dihydrocodeine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Dihydrocodeine interactionAcetaminophen, Caffeine, IsomethepteneMigralam
How Acetaminophen, Caffeine, Isometheptene interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Isometheptene interactionAcetaminophen, Caffeine, PyrilamineMidol Max Strength Menstrual
How Acetaminophen, Caffeine, Pyrilamine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Caffeine, Pyrilamine interactionAcetaminophen, Chlorpheniramine Maleate, Dextromethorphan HbrVicks Formula 44M Cough, Cold & Flu Relief
How Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Chlorpheniramine Maleate, Dextromethorphan Hbr interactionAcetaminophen, Chlorpheniramine, Codeine, PhenylephrineColrex
How Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Chlorpheniramine, Codeine, Phenylephrine interactionAcetaminophen, Chlorpheniramine, DextromethorphanCoricidin II Extra Strength Cold and Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Chlorpheniramine, Dextromethorphan interactionAcetaminophen, Chlorpheniramine, Dextromethorphan HydrobromideCoricidin HBP Maximum Strength Flu
How Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Chlorpheniramine, Dextromethorphan Hydrobromide interactionAcetaminophen, Chlorpheniramine, Dextromethorphan, PhenylpropanolamineMulti Symptom Cold Relief
How Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interacts with Niacinamide — through 1 ingredient. Tap an ingredient for the detail:
NiacinHepatotoxic Drugs Moderate
Interaction Summary
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Read the full Niacin + Acetaminophen, Chlorpheniramine, Dextromethorphan, Phenylpropanolamine interactionEach ingredient & the kinds of drugs it affects
For each ingredient in Niacinamide with known interactions, here are the types of medications it can affect. Open any type for the detail — or search your exact drug in the checker above.
Niacin
Alcohol (Ethanol)
Concomitant use of alcohol and niacin might increase the risk of flushing and hepatotoxicity.
Alcohol can exacerbate the flushing and pruritus associated with niacin. Large doses of niacin might also exacerbate liver dysfunction associated with chronic alcohol use. A case report describes delirium and lactic acidosis in a patient taking niacin 3 grams daily who ingested 1 liter of wine. Advise patients to avoid large amounts of alcohol while taking niacin.
Allopurinol (Zyloprim)
Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as allopurinol.
Large doses of niacin can reduce urinary excretion of uric acid, potentially resulting in hyperuricemia. Doses of uricosurics such as allopurinol might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.
Anticoagulant/Antiplatelet Drugs
Theoretically, niacin may have additive effects when used with anticoagulant or antiplatelet drugs.
Several cases of clotting factor synthesis deficiency and coagulopathy have been reported in patients taking sustained-release niacin. Also, thrombocytopenia has been reported in patients treated with niacin or niacin plus lovastatin.
Antidiabetes Drugs
Niacin can increase blood glucose levels and may diminish the effects of antidiabetes drugs.
Niacin impairs glucose tolerance in a dose-dependent manner, probably by causing or aggravating insulin resistance and increasing hepatic production of glucose. In diabetes patients, niacin 4.5 grams daily for 5 weeks can increase plasma glucose by an average of 16% and glycated hemoglobin (HbA1c) by 21%. However, lower doses of 1.5 grams daily or less appear to have minimal effects on blood glucose. In some patients, glucose levels increase when niacin is started, but then return to baseline when a stable dose is reached. Up to 35% of patients with diabetes may need adjustments in hypoglycemic therapy when niacin is added.
Antihypertensive Drugs
Theoretically, niacin may increase the risk of hypotension when used with antihypertensive drugs.
The vasodilating effects of niacin can cause hypotension. Furthermore, some clinical evidence suggests that a one-hour infusion of niacin can reduce systolic, diastolic, and mean blood pressure in hypertensive patients. This effect is not observed in normotensive patients.
Bile Acid Sequestrants
Bile acid sequestrants can bind niacin and decrease absorption. Separate administration by 4-6 hours to avoid an interaction.
In vitro studies show that colestipol (Colestid) binds about 98% of available niacin and cholestyramine (Questran) binds 10% to 30%.
Gemfibrozil (Lopid)
Theoretically, concomitant use of niacin and gemfibrozil might increase the risk of myopathy in some patients.
A case of myopathy from concomitant use of niacin and gemfibrozil has been reported. Niacin alone has also been associated with cases of myopathy. Using gemfibrozil with niacin might further increase the risk of developing myopathy.
Hepatotoxic Drugs
Theoretically, concomitant use of niacin and hepatotoxic drugs might increase the risk of hepatotoxicity.
Niacin has been associated with cases of liver toxicity, especially when used in pharmacologic doses. Sustained-release niacin preparations appear to be associated with a higher risk of hepatotoxicity than immediate-release niacin.
Hmg-Coa Reductase Inhibitors ("Statins")
Theoretically, concomitant use of niacin and statins might increase the risk of myopathy and rhabdomyolysis in some patients.
Some case reports have raised concerns that niacin might increase the risk of myopathy and rhabdomyolysis when combined with statins. However, a significantly increased risk of myopathy has not been demonstrated in clinical trials, including those using an FDA-approved combination of lovastatin and niacin (Advicor).
Probenecid (Benemid)
Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as probenecid.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as probenecid might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.
Sulfinpyrazone (Anturane)
Theoretically, niacin might antagonize the therapeutic effects of uricosurics such as sulfinpyrazone.
Large doses of niacin reduce urinary excretion of uric acid, potentially causing hyperuricemia. Doses of uricosurics such as sulfinpyrazone might need to be increased to maintain control of gout in patients who start taking niacin. People who have frequent attacks of gout despite uricosuric therapy should avoid niacin.
Thyroid Hormone
Theoretically, niacin might antagonize the therapeutic effects of thyroid hormones.
Clinical research and case reports suggests that taking niacin can reduce serum levels of thyroxine-binding globulin by up to 25% and moderately reduce levels of thyroxine (T4). Patients taking thyroid hormone for hypothyroidism might need dose adjustments when using niacin.
Transdermal Nicotine (Nicoderm)
Theoretically, concomitant use of niacin and transdermal nicotine might increase the risk of flushing and dizziness.
Niacin and nicotine can both cause flushing and dizziness.
Warfarin (Coumadin)
There is limited evidence that niacin may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 3.9 after taking niacin for two weeks. The patient's INR was previously stable, ranging between 2 and 3 in recent months, and no other medication changes were identified. The elevated INR returned to therapeutic range within 4 days following the discontinuation of niacin.
Aspirin
Large doses of aspirin might alter the clearance of niacin.
Aspirin is often used with niacin to reduce niacin-induced flushing. Doses of 80-975 mg aspirin have been used, but 325 mg appears to be optimal. Aspirin also seems to reduce the clearance of niacin by competing for glycine conjugation. Taking aspirin 1 gram seems to reduce niacin clearance by 45%. This is probably a dose-related effect and not clinically significant with the more common aspirin dose of 325 mg.
Brand information
Manufacturer and brand details for Niacinamide, from the product label.
GNC Mega Men
See all GNC Mega Men products- Name
- General Nutrition Corporation
- City
- Pittsburgh
- State
- PA
- ZipCode
- 15222
- Phone Number
- 1-888-462-2548
- Web Address
- gnc.com
Niacinamide by GNC Mega Men: Common Questions
Does Niacinamide by GNC Mega Men interact with any medications?
How can one product interact with so many drugs?
Where does this information come from?
Will niacin cause that famous flushing feeling?
Can I take niacin if I'm pregnant or breastfeeding?
What stomach problems might niacin cause?
Is niacin safe for my liver?
What does niacin actually do in this product?
Written and reviewed by the HelloPharmacist editorial staff. Our editorial policy
Not sure if Niacinamide is safe with your meds?
Our pharmacists answer your medication & supplement questions — free.
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.
The Full Monographs Behind Niacinamide’s Ingredients
Every ingredient we hold a full HelloPharmacist monograph for — uses, evidence, safety, and the complete interaction list.
Sources & How We Checked
Niacinamide'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.
- NIH Dietary Supplement Label Database (DSLD) — The official product label on file for this supplement.
- Natural Medicines (Therapeutic Research Center) — Evidence-graded clinical reference behind the ingredient interaction data.
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 66 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.
Niacin 66 references
- Garg R, Malinow MR, Pettinger M, et al. Niacin treatment increases plasma homocysteine levels. Am Heart J 1999;138:1082-7.
- Anon. Inositol hexaniacinate. Altern Med Rev 1998;3:222-3.
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- Guyton JR, Blazing MA, Hagar J, et al. Extended-release niacin vs gemfibrozil for the treatment of low levels of high-density lipoprotein cholesterol. Niaspan-Gemfibrozil Study Group. Arch Intern Med 2000;160:1177-84. PubMed
- Gibbons LW, Gonzalez V, Gordon N, Grundy S. The prevalence of side effects with regular and sustained-release nicotinic acid. Am J Med 1995;99:378-85. PubMed
- Whelan AM, Price SO, Fowler SF, Hainer BL. The effect of aspirin on niacin-induced cutaneous reactions. J Fam Pract 1992;34:165-8.
- Jungnickel PW, Maloley PA, Vander Tuin EL, et al. Effect of two aspirin pretreatment regimens on niacin-induced cutaneous reactions. J Gen Intern Med 1997;12:591-6. PubMed
- Capuzzi DM, Guyton JR, Morgan JM, et al. Efficacy and safety of an extended-release niacin (Niaspan): a long-term study. Am J Cardiol 1998;82:74-81;disc. 85U-6U. PubMed
- Gray DR, Morgan T, Chretien SD, Kashyap ML. Efficacy and safety of controlled-release niacin in dyslipoproteinemic veterans. Ann Intern Med 1994;121:252-8. PubMed
- McKenney JM, Proctor JD, Harris S, Chinchili VM. A comparison of the efficacy and toxic effects of sustained- vs immediate-release niacin in hypercholesterolemic patients. JAMA 1994;271:672-7. DOI
- Knopp RH, Alagona P, Davidson M, et al. Equivalent efficacy of a time-release form of niacin (Niaspan) given once-a-night versus plain niacin in the management of hyperlipidemia. Metabolism 1998;47:1097-104. PubMed
- Knopp RH. Clinical profiles of plain versus sustained-release niacin (Niaspan) and the physiologic rationale for nighttime dosing. Am J Cardiol 1998;82:24U-28U;discussion 39U-41U. PubMed
- Garg A, Grundy SM. Nicotinic acid as therapy for dyslipidemia in non-insulin-dependent diabetes mellitus. JAMA 1990;264:723-6. DOI
- Leighton RF, Gordon NF, Small GS, et al. Dental and gingival pain as side effects of niacin therapy. Chest 1998;114:1472-4. PubMed
- American Society of Health-System Pharmacists. ASHP Therapeutic Position Statement on the safe use of niacin in the management of dyslipidemias. Am J Health Syst Pharm 1997;54:2815-9. DOI
- Vega GL, Grundy SM. Lipoprotein responses to treatment with lovastatin, gemfibrozil, and nicotinic acid in normolipidemic patients with hypoalphalipoproteinemia. Arch Intern Med 1994;154:73-82. DOI
- Guyton JR, Goldberg AC, Kreisberg RA, et al. Effectiveness of once-nightly dosing of extended-release niacin alone and in combination for hypercholesterolemia. Am J Cardiol 1998;82:737-43.
- Food and Nutrition Board, Institute of Medicine. Dietary Reference Intakes for Thiamin, Riboflavin, Niacin, Vitamin B6, Folate, Vitamin B12, Pantothenic Acid, Biotin, and Choline (2000). Washington, DC: National Academy Press, 2000. Available at: http://b
- Brown BG, Zhao XQ, Chait A, et al. Simvastatin and niacin, antioxidant vitamins, or the combination for the prevention of coronary disease. N Engl J Med 2001;345:1583-93. DOI
- Bays HE, Dujovne CA. Drug interactions of lipid-altering drugs. Drug Saf 1998;19:355-71. PubMed
- Rader JI, Calvert RJ, Hathcock JN. Hepatic toxicity of unmodified and time-release preparations of niacin. Am J Med 1992;92:77-81. PubMed
- Kahn SE, Beard JC, Schwartz MW, et al. Increased B-cell secretory capacity as mechanism for islet adaptation to nicotinic acid-induced insulin resistance. Diabetes 1989;38:562-8.
- Schwartz ML. Severe reversible hyperglycemia as a consequence of niacin therapy. Arch Int Med 1993;153:2050-2. DOI
- Raising HDL and Niacin Use. Pharmacist's Letter/Prescriber's Letter 2004;20(5):200504.
- McKenney J. New perspectives on the use of niacin in the treatment of lipid disorders. Arch Intern Med 2004;164:697-705. PubMed
- Reaven P, Witztum JL. Lovastatin, nicotinic acid and rhabdomyolysis (letter). Ann Int Med 1988;109:597-8. PubMed
- Ito MK. Advances in the understanding and management of dyslipidemia: using niacin-based therapies. Am J Health-Syst Pharm 2003;60(suppl 2):s15-21. PubMed
- Schwab RA, Bachhuber BH. Delirium and lactic acidosis caused by ethanol and niacin coingestion. Am J Emerg Med 1991;9:363-5. PubMed
- Product information: Niaspan. Kos Pharmaceuticals. Cranbury, NJ. 2005. Available at www.niaspan.com/professional/content/pdfs/productinfo.pdf. (Accessed 3 March 2006).
- Ding RW, Kolbe K, Merz B, et al. Pharmacokinetics of nicotinic acid-salicylic acid interaction. Clin Pharmacol Ther 1989;46:642-7. PubMed
- NIH News. NIH stops clinical trial on combination cholesterol treatment. May 26, 2011. http://www.nih.gov/news/health/may2011/nhlbi-26.htm. (Accessed 3 June 2011).
- Dearing BD, Lavie CJ, Lohmann TP, Genton E. Niacin-induced clotting factor synthesis deficiency with coagulopathy. Arch Intern Med. 1992;152(4):861-3. DOI
- O'Brien T, Silverberg JD, Nguyen TT. Nicotinic acid-induced toxicity associated with cytopenia and decreased levels of thyroxine-binding globulin. Mayo Clin Proc. 1992;67(5):465-8. PubMed
- Gadegbeku CA, Dhandayuthapani A, Shrayyef MZ, Egan BM. Hemodynamic effects of nicotinic acid infusion in normotensive and hypertensive subjects. Am J Hypertens. 2003;16(1):67-71. PubMed
- Garnett WR. Interactions with hydroxymethylglutaryl-coenzyme A reductase inhibitors. Am J Health Syst Pharm. 1995;52(15):1639-45. PubMed
- Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
- Dunn RT, Ford MA, Rindone JP, Kwiecinski FA. Low-Dose Aspirin and Ibuprofen Reduce the Cutaneous Reactions Following Niacin Administration. Am J Ther. 1995;2(7):478-480. PubMed
- Cashin-Hemphill L, Spencer CA, Nicoloff JT, et al. Alterations in serum thyroid hormonal indices with colestipol-niacin therapy. Ann Intern Med. 1987;107(3):324-9. PubMed
- Drinka PJ. Alterations in thyroid and hepatic function tests associated with preparations of sustained-release niacin. Mayo Clin Proc. 1992;67(12):1206. PubMed
- Shakir KM, Kroll S, Aprill BS, Drake AJ 3rd, Eisold JF. Nicotinic acid decreases serum thyroid hormone levels while maintaining a euthyroid state. Mayo Clin Proc. 1995;70(6):556-8. PubMed
- Etchason JA, Miller TD, Squires RW, et al. Niacin-induced hepatitis: a potential side effect with low-dose time-release niacin. Mayo Clin Proc. 1991;66(1):23-8. PubMed
- Henkin Y, Johnson KC, Segrest JP. Rechallenge with crystalline niacin after drug-induced hepatitis from sustained-release niacin. JAMA. 1990;264(2):241-3. DOI
- Henkin Y, Oberman A, Hurst DC, Segrest JP. Niacin revisited: clinical observations on an important but underutilized drug. Am J Med. 1991;91(3):239-46. PubMed
- Brown BG, Bardsley J, Poulin D, et al. Moderate dose, three-drug therapy with niacin, lovastatin, and colestipol to reduce low-density lipoprotein cholesterol <100 mg/dl in patients with hyperlipidemia and coronary artery disease. Am J Cardiol. 1997;80(2)
- Goldberg A, Alagona P Jr, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in the management of hyperlipidemia. Am J Cardiol. 2000;85(9):1100-5. PubMed
- Aronov DM, Keenan JM, Akhmedzhanov NM, et al. Clinical trial of wax-matrix sustained-release niacin in a Russian population with hypercholesterolemia. Arch Fam Med. 1996;5(10):567-75. PubMed
- Morgan JM, Capuzzi DM, Guyton JR, et al. Treatment Effect of Niaspan, a Controlled-release Niacin, in Patients With Hypercholesterolemia: A Placebo-controlled Trial. J Cardiovasc Pharmacol Ther. 1996;1(3):195-202. PubMed
- Andersson RG, Aberg G, Brattsand R, Ericsson E, Lundholm L. Studies on the mechanism of flush induced by nicotinic acid. Acta Pharmacol Toxicol (Copenh). 1977 Jul;41(1):1-10. PubMed
- Brown WV. Niacin for lipid disorders. Indications, effectiveness, and safety. Postgrad Med. 1995 Aug;98(2):185-9, 192-3. PubMed
- O'REILLY PO, CALLBECK MJ, HOFFER A. Sustained-release nicotinic acid (nicospan); effect on (1) cholesterol levels and (2) leukocytes. Can Med Assoc J. 1959;80(5):359-62.
- Gharavi AG, Diamond JA, Smith DA, Phillips RA. Niacin-induced myopathy. Am J Cardiol. 1994;74(8):841-2. PubMed
- Litin SC, Anderson CF. Nicotinic acid-associated myopathy: a report of three cases. Am J Med. 1989;86(4):481-3. PubMed
- Fraunfelder FW, Fraunfelder FT, Illingworth DR. Adverse ocular effects associated with niacin therapy. Br J Ophthalmol 1995;79:54-56. PubMed
- Ali EH, McJunkin B, Jubelirer S, Hood W. Niacin induced coagulopathy as a manifestation of occult liver injury. W V Med J. 2013 Jan-Feb;109(1):12-4
- Aramwit P, Srisawadwong R, Supasyndh O. Effectiveness and safety of extended-release nicotinic acid for reducing serum phosphorus in hemodialysis patients. J Nephrol. 2012 May-Jun;25(3):354-62. PubMed
- Bassan M. A case for immediate-release niacin. Heart Lung. 2012 Jan-Feb;41(1):95-8. PubMed
- Davidson MH, Rooney M, Pollock E, Drucker J, Choy Y. Effect of colesevelam and niacin on low-density lipoprotein cholesterol and glycemic control in subjects with dyslipidemia and impaired fasting glucose. J Clin Lipidol. 2013 Sep-Oct;7(5):423-32. PubMed
- Guyton JR, Fazio S, Adewale AJ, Jensen E, Tomassini JE, Shah A, Tershakovec AM. Effect of extended-release niacin on new-onset diabetes among hyperlipidemic patients treated with ezetimibe/simvastatin in a randomized controlled trial. Diabetes Care. 2012 PubMed
- Loebl T, Raskin S. A novel case report: acute manic psychotic episode after treatment with niacin. J Neuropsychiatry Clin Neurosci. 2013 Fall;25(4):E14. PubMed
- Teo KK, Goldstein LB, Chaitman BR, Grant S, Weintraub WS, Anderson DC, Sila CA, Cruz-Flores S, Padley RJ, Kostuk WJ, Boden WE; AIM-HIGH Investigators. Extended-release niacin therapy and risk of ischemic stroke in patients with cardiovascular disease: the
- Goldie C, Taylor AJ, Nguyen P, McCoy C, Zhao XQ, Preiss D. Niacin therapy and the risk of new-onset diabetes: a meta-analysis of randomized controlled trials. Heart. 2016 Feb;102(3):198-203.
- Schandelmaier S, Briel M, Saccilotto R, Olu KK, Arpagaus A, Hemkens LG, Nordmann AJ. Niacin for primary and secondary prevention of cardiovascular events. Cochrane Database Syst Rev. 2017 Jun 14;6:CD009744. PubMed
- Jenkins DJA, Spence JD, Giovannucci EL, et al. Supplemental vitamins and minerals for CVD prevention and treatment. J Am Coll Cardiol 2018;71(22):2570-84. PubMed
- Song S, Lee CJ, Oh J, Park S, Kang SM, Lee SH. Effect of Niacin on Carotid Atherosclerosis in Patients at Low-Density Lipoprotein-Cholesterol Goal but High Lipoprotein (a) Level: a 2-Year Follow-Up Study. J Lipid Atheroscler. 2019;8(1):58-66. PubMed
- Kimura H, Umemori Y, Yuki D. Anaphylactic shock-like symptoms due to niacin overdose: A case report. J Dermatol 2022;49(8):e287-e288. PubMed
- Nawaz N, Mistretta T, Karime C, Lewis J, Wolf E. Cholestatic Drug-Induced Liver Injury in a Patient Taking High-Dose Niacin for Hyperlipidemia. J Investig Med High Impact Case Rep 2024;12:23247096231224349. PubMed
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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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