Vitamin B3 (Niacinamide)
Also known as: Nicotinamide, Niacin Amide
Niacinamide, a form of Vitamin B3, plays a vital role in cellular energy metabolism as a precursor to NAD+ and NADP+. Research indicates its efficacy in supporting skin health, particularly in reducing inflammation, improving skin barrier function, and potentially reducing the risk of non-melanoma skin cancers. It also exhibits anti-inflammatory properties and may have benefits in metabolic health, though direct supplementation benefits beyond deficiency are still under investigation for many applications.
Last reviewed: 2026-04-22 · 4 indexed studies
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Overview
Niacinamide is one of two primary forms of Vitamin B3, the other being nicotinic acid. It is a water-soluble vitamin and a precursor to nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+), which are crucial coenzymes involved in numerous cellular metabolic processes.
Mechanism & Function
Niacinamide · C₆H₆N₂O — source: PubChem CID 936
White crystalline non-flushing form of B3. Highly water-soluble.
- Capsule
- Tablet
- Powder
- Liquid
Capsule is generally preferred for bioavailability or efficacy.
Mechanism of Action
Niacinamide is converted to nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+). NAD+ and NADP+ are essential coenzymes for over 400 enzymatic reactions, primarily in redox reactions involved in energy metabolism (glycolysis, oxidative phosphorylation, fatty acid oxidation) and DNA repair. Niacinamide also directly influences cellular signaling pathways and has anti-inflammatory properties by inhibiting pro-inflammatory cytokines.
Physiological Role
As a precursor to NAD+ and NADP+, niacinamide is fundamentally involved in cellular energy production, DNA repair, and maintaining genomic stability. It is crucial for the metabolism of carbohydrates, fats, and proteins. It also plays a role in cellular communication and antioxidant defense mechanisms.
Primary Pathways
Performance / Health Relevance
While directly improving athletic performance is not a primary role, niacinamide's involvement in energy metabolism via NAD+ production supports overall cellular function which is indirectly relevant to metabolic efficiency. Its skin health benefits can protect against sun damage, which can be a concern for outdoor athletes.
Evidence Review
Compare Vitamin B3 (Niacin) Forms
Full comparison5 vitamin b3 (niacin) forms are indexed. Bioavailability, clinical evidence, and best-use cases differ meaningfully between them.
| Form | Evidence |
|---|---|
Vitamin B3 (Niacinamide)This page Highly bioavailable orally, with absorption rates typically exceeding 90%. | 65/100 |
| Vitamin B3 (Niacin) Both nicotinic acid and nicotinamide are well absorbed orally. Nicotinic acid has varying pharmacokinetic profiles depending on the formulation (immediate-release vs. sustained-release). | 80/100 |
| Nicotinamide Riboside Oral NR increases circulating NAD+ and, in at least one trial, brain NAD+; magnitude of change is variable between individuals. | 61/100 |
| NMN Oral NMN raises plasma NAD+; sublingual delivery may improve bypass of gut conversion. | 54/100 |
| Nicotinamide Mononucleotide Rapidly absorbed and converted to NAD+ within 30 minutes. Some degradation by CD73 ectoenzyme in the GI tract — sublingual delivery may improve yield. | 50/100 |
Practical Use & Dosage
- Minimum Effective Dose
- 250 mg/day
- Optimal Range
- 250-1000 mg/day
- Upper / Caution Level
- 3000 mg/day (for certain therapeutic uses, often lower for general supplementation)
- Timing
- Can be taken with or without food. Daily dosage can be split to improve tolerability and absorption.
- Best Format
- Oral capsules or tablets. Topical formulations for skin health.
- Bioavailability
- Highly bioavailable orally, with absorption rates typically exceeding 90%.
- Absorption Considerations
- Generally well-absorbed. No specific dietary factors significantly impede absorption.
Safety & Interactions
Side Effects
- •Mild gastrointestinal upset (high doses)
- •Skin flushing (rare with niacinamide, more common with nicotinic acid)
- •Headache (rare)
Contraindications
- None well-established at typical supplemental doses. Caution in individuals with pre-existing liver conditions at very high therapeutic doses.
Drug Interactions
- •May interact with certain medications for glaucoma (e.g., pilocarpine) by potentially reducing their effectiveness if applied topically to the eye.
- •Potential additive effect with blood pressure-lowering medications at extremely high doses.
Who Should Avoid
- •Individuals with known hypersensitivity to niacinamide. Those with severe liver disease should consult a healthcare professional at very high doses.
Monitoring
Liver enzyme monitoring may be warranted at very high therapeutic doses (e.g., >3g/day), but generally not necessary for typical supplemental doses.
Frequently Asked Questions
Auto-generated from indexed evidence — dosage, safety, interactions, and more.
When is Vitamin B3 (Niacinamide) typically used or indicated?
Vitamin B3 (Niacinamide) is most commonly used for: Skin health, NAD+ precursor, Metabolic health, Anti-inflammatory. As a precursor to NAD+ and NADP+, niacinamide is fundamentally involved in cellular energy production, DNA repair, and maintaining genomic stability. It is crucial for the metabolism of carbohydrates, fats, and proteins. It also plays a role in cellular communication and antioxidant defense mechanisms.
How does Vitamin B3 (Niacinamide) work?
Niacinamide is converted to nicotinamide adenine dinucleotide (NAD+) and nicotinamide adenine dinucleotide phosphate (NADP+). NAD+ and NADP+ are essential coenzymes for over 400 enzymatic reactions, primarily in redox reactions involved in energy metabolism (glycolysis, oxidative phosphorylation, fatty acid oxidation) and DNA repair. Niacinamide also directly influences cellular signaling pathways and has anti-inflammatory properties by inhibiting pro-inflammatory cytokines.
What is the recommended dose of Vitamin B3 (Niacinamide)?
The optimal range is 250-1000 mg/day. with a minimum effective dose of 250 mg/day. Best taken: Can be taken with or without food. Daily dosage can be split to improve tolerability and absorption.. Upper / caution level: 3000 mg/day (for certain therapeutic uses, often lower for general supplementation).
What are the side effects of Vitamin B3 (Niacinamide)?
Reported side effects include: Mild gastrointestinal upset (high doses); Skin flushing (rare with niacinamide, more common with nicotinic acid); and Headache (rare). Monitoring: Liver enzyme monitoring may be warranted at very high therapeutic doses (e.g., >3g/day), but generally not necessary for typical supplemental doses.
Does Vitamin B3 (Niacinamide) interact with medications?
Known or theoretical interactions: May interact with certain medications for glaucoma (e.g., pilocarpine) by potentially reducing their effectiveness if applied topically to the eye.; and Potential additive effect with blood pressure-lowering medications at extremely high doses.. Always check with a clinician before combining with prescription medication.
Who should avoid Vitamin B3 (Niacinamide)?
Vitamin B3 (Niacinamide) is generally not recommended for: Individuals with known hypersensitivity to niacinamide. Those with severe liver disease should consult a healthcare professional at very high doses.; and None well-established at typical supplemental doses. Caution in individuals with pre-existing liver conditions at very high therapeutic doses..
How strong is the evidence for Vitamin B3 (Niacinamide)?
Evidence level: Moderate (overall score 65/100), based on 4 indexed studies on SuppIndex.
Research & References (4)
A randomized, controlled trial of nicotinamide for skin cancer chemoprevention in high-risk individuals.
This study investigated the efficacy of oral nicotinamide in reducing the incidence of non-melanoma skin cancer and actinic keratoses in individuals with a history of these lesions.
The effect of nicotinamide on the skin barrier and inflammation in rosacea.
This study evaluated the effect of topical 2% niacinamide on skin barrier function and inflammation in patients with rosacea.
Nicotinamide in the treatment of acne vulgaris: A review.
This systematic review synthesized evidence on the effectiveness of topical and oral nicotinamide for the treatment of acne vulgaris.
Nicotinamide: A Potential Multi-Faceted Agent for Skin Cancer Chemoprevention.
This review discusses the mechanisms and clinical evidence for nicotinamide's role in skin cancer chemoprevention.
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Research Overview
Moderate EvidenceCite this ingredient
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Stable URL
https://thesuppindex.com/ingredients/vitamin-b3-niacinamide
SuppIndex. (2026). Vitamin B3 (Niacinamide): Evidence summary, dosage and clinical studies. Retrieved October 23, 2026, from https://thesuppindex.com/ingredients/vitamin-b3-niacinamide
Based on 4 indexed studies · Evidence level: Moderate.
Goal Ratings
Stack Compatibility
Generally very compatible with most supplements. Often included in multivitamin formulations and B-complex vitamins.