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Dietary supplement

Niacinamide (Vitamin B3) 650 mg Ingredients & Drug Interactions

by BulkSupplements.com

Niacinamide (Vitamin B3) 650 mg label
See full label image
Capsule Category: Vitamin
Most serious interaction: Moderate
Clinical methodology reviewed by · Updated Sep 16, 2026 · Label data from the NIH DSLD
What is this page for?

First and foremost: checking Niacinamide (Vitamin B3) 650 mg against your medications. The heart of this page is the interaction checker and the full interaction report — how this product’s ingredients may interact with prescription and over-the-counter medicines you may be taking.

Around that, we add a pharmacist’s high-level view of the product as a whole — what’s inside, the evidence for its stated use, how transparent the label is, and what safety data exists — so you can see the full picture in one place. It’s educational information from our licensed clinical databases and the clinical staff at HelloPharmacist — not medical advice — and we don’t sell or endorse products. Our editorial policy

The interaction bottom line Most serious interaction: Moderate

Niacinamide (Vitamin B3) 650 mg is a dietary supplement by BulkSupplements.com with 1 active ingredient. Its ingredients are commonly taken for acne and skin health, pellagra (niacin deficiency), anti-aging and skin tone.Based on those ingredients, 124 medications have a known interaction with it, the most serious rated moderate. The ingredients most likely to interact are Niacinamide. Use the checker below to test your specific medication, or read the full HelloPharmacist Interaction Report.

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Check Your Meds Against Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com

Ask about any prescription or over-the-counter medication and we check it for interactions with Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com — and tell you which ingredient is responsible.

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HelloPharmacist Scorecard of Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com

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 1 of its 1 active ingredient.
  • No proprietary blends here — you can verify the dose of every single component.

This product contains one active ingredient: niacinamide (also called nicotinamide), a form of vitamin B3, at 650 mg per capsule. Niacinamide is a water-soluble vitamin your body needs for energy production and cell repair.

The capsule itself is made from hypromellose, a plant-based capsule material.

Does it work?

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

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

Strong

Strong clinical evidence supports Niacinamide for:

Why this rating?
  • We looked at the product name, claims, and label statements and couldn't find a stated purpose to grade.
  • Since the label doesn't commit to one use, we graded the ingredient's overall clinical evidence instead.
  • On file: Pellagra — rated "Likely Effective" (Natural Medicines).
  • On file: Acne — rated "Possibly Effective" (Natural Medicines).
  • On file: Diabetes — rated "Possibly Effective" (Natural Medicines).
  • On file: Osteoarthritis — rated "Possibly Effective" (Natural Medicines).
  • On file: Hyperphosphatemia — rated "Possibly Effective" (Natural Medicines).

Niacinamide is likely effective for pellagra, a vitamin B3 deficiency disease. It's possibly effective for acne, high blood phosphate (hyperphosphatemia), osteoarthritis, and diabetes based on the evidence we hold.

For brain tumors, the data suggests it's possibly ineffective. If you're considering this for one of those uses, talk it over with your doctor to see if it's the right choice for your situation.

The evidence, ingredient by ingredient Niacinamide

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 1 of the 1 matched ingredient.
  • Pregnancy & breastfeeding safety ratings cover 1 of 1.
  • General safety write-ups exist for 1 of 1.
  • Remember: this measures how much safety information exists. Thin data is not the same as being safe.

Niacinamide at normal dietary amounts and the doses in standard prenatal vitamins is generally well tolerated and considered safe in pregnancy and breastfeeding. Higher supplemental doses in pregnancy should only be used if your doctor advises it.

At recommended amounts, this supplement is generally well tolerated, though high doses can cause side effects and should be supervised by a healthcare provider. The most common oral side effects at higher doses are dizziness, drowsiness, itching, stomach upset, headache, and rash.

Large doses can also trigger nausea, vomiting, heartburn, loss of appetite, stomach pain, gas, and diarrhea.

Side effects, ingredient by ingredient Niacinamide

Meds to double-check

Moderate interaction found
Known Interaction Concern · database check
Moderate identified

The most serious documented interaction for these ingredients is Moderate. Check your medications for a personalized result.

Why this rating?
  • 1 of the 1 matched ingredient can interact with medications — Niacinamide.
  • The most serious interaction on file is rated Moderate.
  • Some involve high-stakes drug classes: anticoagulant / antiplatelet drugs.
  • For scale: 124 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 you take this product, check with your doctor or pharmacist if you're on blood thinners (anticoagulants) like warfarin or antiplatelet drugs — niacinamide may boost their effect. Also flag it if you take the anti-seizure medications carbamazepine or primidone, as niacinamide can raise their blood levels.

Use the medication checker on this page to search your exact drugs.

Check your own medication Run your meds through the checker above

The bottom line

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

Niacinamide at this dose is a straightforward B3 supplement, likely effective for pellagra and possibly helpful for acne, joint pain, and blood sugar management. If you take blood thinners, anti-seizure drugs, or are on hemodialysis, check your medications with the tool on this page before starting — the interactions are real and worth confirming with your own doctor or pharmacist.

Otherwise, it's generally well tolerated at recommended doses.

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 Jun 23, 2021.

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 Niacinamide (Vitamin B3) 650 mg, straight from the product label.

Brand BulkSupplements.com
Net contents 300 Vegetarian Capsule(s)
Market status On market
Date entered into DSLD Jun 23, 2021
DSLD ID 252730
Product type Vitamin
Supplement form Capsule
Dietary claims / uses All Other, Structure/Function
Intended target group(s) Adult (18 - 50 Years), Gluten Free, Dairy Free
From the label
Everything in this section is reproduced from the manufacturer’s own product label — it’s the label speaking, not HelloPharmacist. We show it so you can see exactly what the maker states; we don’t verify or endorse those statements.

Supplement Facts

The label details for Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com, 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
300
IngredientAmount% DV
Niacinamide650 mg3250%

Other ingredients: Hypromellose Capsules

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.
General Statements

Clean & Pure Bulk Supplements

Precautions

Warning: This product is not intended for use by those with a serious medical condition or pregnant or lactating women.

Consult your physician before use.

Keep out of reach of children!

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.

Formulation

Free of: Soy, dairy, yeast, gluten or additives

Suggested/Recommended/Usage/Directions

Directions: As a dietary supplement, take 1 capsule with a meal or as directed by a physician.

Storage

Storage: Keep dry, cool & dark

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

See for yourself

Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com label

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

Niacinamide (Vitamin B3) 650 mg 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 Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com

This is the 1 active ingredient this product is made of. Select it to open its full monograph.

Serving size1 Capsule(s) Dosage formCapsule Servings per container300 Amounts shown are per serving.

Niacinamide

Interacts with
124 drugs
650 mg per serving

Niacinamide (also called nicotinamide) is a form of vitamin B3 used in supplements and skin-care products. It is well established for preventing and t...

Niacinamide monograph & interactions

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

Interaction report

Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com Drug Interactions

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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
124Drugs
124 Moderate

Ingredients driving the most interactions

Niacinamide 124

Individual Drug Interactions

The ingredients in Niacinamide (Vitamin B3) 650 mg interact with 124 drugs. Click any drug to see the details.

1 of the 1 ingredient in Niacinamide (Vitamin B3) 650 mg interact with drugs. Each result below shows which ingredient is responsible. Niacinamide

Each ingredient & the kinds of drugs it affects

For each ingredient in Niacinamide (Vitamin B3) 650 mg 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.

Niacinamide4 drug types · 124 drugs

Anticoagulant/Antiplatelet Drugs

Theoretically, niacinamide may have additive effects when used with anticoagulant or antiplatelet drugs, especially in patients on hemodialysis.
Several cases of thrombocytopenia have been reported for hemodialysis patients treated with niacinamide 1 gram daily. Hemodialysis patients receiving niacinamide had almost a three-fold higher risk of developing thrombocytopenia when compared with those receiving placebo.

Likelihood Unlikely Evidence D
Carbamazepine (Tegretol)

Niacinamide might increase the levels and adverse effects of carbamazepine.
Plasma levels of carbamazepine were increased in two children given high-dose niacinamide, 60-80 mg/kg/day. This might be due to inhibition of the cytochrome P450 enzymes involved in carbamazepine metabolism. There is not enough data to determine the clinical significance of this interaction.

Likelihood Possible Evidence D
Primidone (Mysoline)

Niacinamide might increase the levels and adverse effects of primidone.
Case reports in children suggest niacinamide 60-100 mg/kg/day reduces hepatic metabolism of primidone to phenobarbital, and reduces the overall clearance rate of primidone; however, there is not enough data to determine the clinical significance of this potential interaction.

Likelihood Possible Evidence D
Warfarin (Coumadin)

There is limited evidence that niacinamide may increase the anticoagulant effects of warfarin.
In a case report, a patient on warfarin developed an elevated international normalized ratio (INR) of 8.4 after taking niacinamide 500 mg twice daily for 10 days. The patient's INR was previously stable, ranging between 2 and 3, with no other changes to current medications or diet reported. The elevated INR returned to the therapeutic range after receiving vitamin K and discontinuing niacinamide.

Likelihood Possible Evidence D
Niacinamide full monograph & interactions
The maker

Brand information

Manufacturer and brand details for Niacinamide (Vitamin B3) 650 mg, from the product label.

BulkSupplements.com

See all BulkSupplements.com products
Name
BulkSupplements.com
Street Address
7511 Eastgate Road
City
Henderson
State
NV
ZipCode
89011
Web Address
BulkSupplements.com
Pharmacist Counseling Corner

Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com: Common Questions

Does Niacinamide (Vitamin B3) 650 mg by BulkSupplements.com interact with any medications?
Yes. Based on its ingredients, Niacinamide (Vitamin B3) 650 mg has a known interaction with 124 medications. Use the checker to see how it interacts with a specific drug.
How can one product interact with so many drugs?
Niacinamide (Vitamin B3) 650 mg contains a single active ingredient, and that one ingredient can interact with many different medications on its own. We check it against each medication and show the mechanism 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 niacinamide safe to take while pregnant?
Normal dietary amounts and the doses in standard prenatal vitamins are considered safe. High supplemental doses should only be used if your doctor advises it. Talk with your healthcare provider about your specific situation.
What's the difference between niacinamide and niacin?
Both are forms of vitamin B3, but niacinamide (also called nicotinamide) doesn't cause the flushing or heat sensation that regular niacin does. This product contains niacinamide.
What side effects might I get from this dose?
At recommended amounts, niacinamide is generally well tolerated. If you take higher doses, you might notice dizziness, drowsiness, itching, stomach upset, headache, or rash. Very high doses can cause nausea, vomiting, heartburn, or diarrhea.
Does this product contain any fillers?
The capsule is made from hypromellose, a plant-based capsule material. There are no other inactive ingredients listed.
Will this help my acne or joint pain?
Niacinamide is possibly effective for both acne and osteoarthritis based on the evidence we have, but results vary. It's worth discussing with your doctor to see if it's a good fit for your needs and how long to give it a fair trial.
Can I take this if I'm on blood thinners?
Niacinamide may add to the effects of blood thinners, which could be risky — especially at higher doses or if you're on hemodialysis. Check your specific medications with your doctor or pharmacist before starting.

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.

Niacinamide (Vitamin B3) 650 mg label
Go deeper

The Full Monographs Behind Niacinamide (Vitamin B3) 650 mg’s Ingredients

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

Herb & supplement monograph

Niacinamide

Interacts with 124 drugs

Niacinamide (also called nicotinamide) is a form of vitamin B3 used in supplements and skin-care products. It is well established for preventing and treating vitamin B3 deficiency, and there...

Read the full Niacinamide monograph →
Sources

Sources & How We Checked

Niacinamide (Vitamin B3) 650 mg'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 22 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.

Niacinamide 22 references
  1. Pozzilli P, Browne PD, Kolb H. Meta-analysis of nicotinamide treatment in patients with recent-onset IDDM. The Nicotinamide Trialists. Diabetes Care 1996;19:1357-63. PubMed
  2. Greenbaum CJ, Kahn SE, Palmer JP. Nicotinamide's effects on glucose metabolism in subjects at risk for IDDM. Diabetes 1996;45:1631-4. DOI
  3. 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
  4. Anon. Niacinamide Monograph. Alt Med Rev 2002;7:525-9.
  5. Miralbell R, Mornex F, Greiner R, et al. Accelerated radiotherapy, carbogen, and nicotinamide in glioblastoma multiforme: report of European Organization for Research and Treatment of Cancer trial 22933. J Clin Oncol 1999;17:3143-9. PubMed
  6. Fatigante L, Ducci F, Cartei F, et al. Carbogen and nicotinamide combined with unconventional radiotherapy in glioblastoma multiforme: a new modality treatment. Int J Radiat Oncol Biol Phys 1997;37:499-504. PubMed
  7. Hoskin PJ, Stratford MR, Saunders MI, et al. Administration of nicotinamide during chart: pharmacokinetics, dose escalation, and clinical toxicity. Int J Radiat Oncol Biol Phys 1995;32:1111-9. PubMed
  8. Papa CM. Niacinamide and acanthosis nigricans (letter). Arch Dermatol 1984;120:1281. DOI
  9. Bourgeois BF, Dodson WE, Ferrendelli JA. Interactions between primidone, carbamazepine, and nicotinamide. Neurology 1982;32:1122-6.
  10. Visalli N, Cavallo MG, Signore A, et al. A multi-centre randomized trial of two different doses of nicotinamide in patients with recent-onset type 1 diabetes (the IMDIAB VI). Diabetes Metab Res Rev 1999;15:181-5. DOI
  11. Rottembourg JB, Launay-Vacher V, Massard J. Thrombocytopenia induced by nicotinamide in hemodialysis patients. Kidney Int. 2005;68(6):2911-2. PubMed
  12. Fabbrocini G, Cantelli M, Monfrecola G. Topical nicotinamide for seborrheic dermatitis: an open randomized study. J Dermatolog Treat. 2014 Jun;25(3):241-5. PubMed
  13. Khodaeiani E, Fouladi RF, Amirnia M, Saeidi M, Karimi ER. Topical 4% nicotinamide vs. 1% clindamycin in moderate inflammatory acne vulgaris. Int J Dermatol. 2013 Aug;52(8):999-1004. PubMed
  14. Zhang Y, Ma T, Zhang P. Efficacy and safety of nicotinamide on phosphorus metabolism in hemodialysis patients: A systematic review and meta-analysis. Medicine (Baltimore). 2018;97(41):e12731. PubMed
  15. Ketteler M, Wiecek A, Rosenkranz AR, et al. Efficacy and Safety of a Novel Nicotinamide Modified-Release Formulation in the Treatment of Refractory Hyperphosphatemia in Patients Receiving Hemodialysis-A Randomized Clinical Trial. Kidney Int Rep 2020;6(3): PubMed
  16. Mainville L, Smilga AS, Fortin PR. Effect of Nicotinamide in Skin Cancer and Actinic Keratoses Chemoprophylaxis, and Adverse Effects Related to Nicotinamide: A Systematic Review and Meta-Analysis. J Cutan Med Surg 2022;26(3):297-308. PubMed
  17. Nouh AH, Elshahid AR, Kadah AS, Zeyada YA. Topical niacinamide (Nicotinamide) treatment for discoid lupus erythematosus (DLE): A prospective pilot study. J Cosmet Dermatol 2023.
  18. El-Khalawany M, Nouh AH, Kadah AS, Elsheikh M, Said M. Evaluation of safety and efficacy of topical 4% nicotinamide in treatment of psoriasis; among a representative sample of Egyptians (an analytical observational study). Dermatol Ther 2022;35(9):e15734. PubMed
  19. Zhang H, George-Washburn EA, Hashemi KB, et al. Oral Nicotinamide for Actinic Keratosis Prevention in Kidney Transplant Recipients: A Pilot Double-Blind, Randomized, Placebo-Controlled Trial. Transplant Proc 2023;55(9):2079-2084. PubMed
  20. Oh HJ, Bae SC, Oh IJ, et al. Nicotinamide in Combination with EGFR-TKIs for the Treatment of Stage IV Lung Adenocarcinoma with EGFR Mutations: A Randomized Double-Blind (Phase IIb) Trial. Clin Cancer Res 2024;30(8):1478-1487. PubMed
  21. Schepers L, Jans I, Pot GK, Smilde AJ, Hofstra JM, de Roos NM. The Effect of Niacinamide Supplementation on Phosphate Concentrations in Dutch Dialysis Patients: A Randomized Crossover Trial. J Ren Nutr 2024;34(5):454-462. PubMed
  22. Markham DJ, Barbosa NS, Degesys CA. Elevated International Normalized Ratio After Initiation of Niacin and Niacinamide Chemoprophylaxis for Patients on Warfarin. Dermatol Surg 2024;50(7):690-692. PubMed

See these in context on the Niacinamide monograph →

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

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

© 2021 Therapeutic Research Center, LLC

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