Niacinamide Injection

Generic Name: Niacinamide (Nicotinamide)
Class: Water-soluble vitamin; Vitamin B3 amide derivative
Pharmacologic Category: Nutritional supplement; coenzyme precursor
Available Forms (clinical use):

• Injectable niacinamide (varies by manufacturer; usually 100 mg/mL or similar concentration)
• Also available in oral tablet/capsules, but this monograph addresses IV use

Clinical Indications for Injectable Niacinamide (evidence-based):

• Treatment or prevention of niacin deficiency (pellagra) when oral administration is not possible
• Part of specially formulated parenteral nutrition solutions
• Severe malabsorption states requiring parenteral vitamin support

Off-label uses sometimes seen in wellness clinics:

• Part of “IV vitamin drips,” antioxidant infusions, “skin brightening” protocols
  Important: These uses lack robust clinical trial data and should be performed only with full informed consent and medical oversight.

Important Safety Note: Specific IV dosing should only be determined by a licensed prescriber. Below are standard medical references, not individualized medical advice.

Evidence-Based Therapeutic Doses (for deficiency / hospital use)

• Adults: Typically 100–500 mg/day IV, depending on severity of deficiency and clinical status
• Pellagra (severe deficiency): Sometimes up to 1,000 mg/day divided IV/IM/PO, then tapered
• Parenteral nutrition: Incorporated into multivitamin formulations (usually 40 mg/day)

Infusion Considerations

• Given slow IV infusion to reduce adverse reactions
• Should not be mixed with incompatible solutions (see interactions)
• Must use sterile, preservative-free medical-grade products intended for injection

NOT recommended:

• Very high-dose IV niacinamide for “anti-aging,” “detox,” or “energy drips,” due to lack of evidence and risk of hepatic toxicity.

Niacinamide is a biologically active form of Vitamin B3 that acts as a precursor of:

1. NAD⁺ (Nicotinamide adenine dinucleotide)

• Essential for cellular energy metabolism (glycolysis, Krebs cycle, oxidative phosphorylation)
• Required for ATP production in mitochondria

2. NADP⁺ (Nicotinamide adenine dinucleotide phosphate)

• Important for fatty acid synthesis, cholesterol metabolism, and detoxification reactions
• Plays a major role in antioxidant pathways (glutathione regeneration)

3. DNA Repair & Cell Survival

Niacinamide supports enzymes such as:

• Poly(ADP-ribose) polymerases (PARPs) — involved in DNA repair
• Sirtuins — regulate aging, metabolism, and inflammation

4. Anti-inflammatory Actions

• Reduces production of inflammatory cytokines
• Modulates neutrophil chemotaxis
• Stabilizes epidermal barrier function

5. Skin Effects

• Reduces melanosome transfer (may help hyperpigmentation)
• Improves epidermal barrier by increasing ceramide synthesis
• Antioxidant properties reduce oxidative stress

Absolute Contraindications

• Known hypersensitivity to niacinamide or formulation components
• Severe hepatic impairment (risk of hepatotoxicity)

Relative Contraindications / Use With Caution

• Renal impairment (accumulation possible at very high doses)
• Active peptic ulcer disease
• Uncontrolled gout or hyperuricemia
• Diabetes mellitus
  • Niacinamide may affect glucose tolerance
• Hypotension
  • Vasodilatory effects may exacerbate low blood pressure
• History of severe flushing reaction to niacin
  • Niacinamide produces minimal flushing but caution is still advised

IV-specific Precautions

• Must be given slowly to prevent local irritation or systemic reactions
• Monitor LFTs in prolonged or high-dose therapy
• Use caution in patients with multiple vitamin infusions to avoid cumulative toxicity

Potential Interactions

• Carbamazepine, valproic acid
  • Additive hepatic stress
• Isoniazid
  • Alters vitamin metabolism; may require adjustment
• Anticoagulants (warfarin)
  • Rare reports of altered INR; monitor closely
• Hypoglycemic agents
  • Niacinamide may impair glucose tolerance

Nutrient Interactions

• Works synergistically with riboflavin (B2), which helps NAD/NADP recycling
• High doses may alter metabolism of other B-complex vitamins
• In parenteral nutrition, must be included in balanced multivitamin mixture to prevent imbalance

Compatibility (IV)

• Compatible in many parenteral nutrition solutions
• Avoid mixing with:
  • Strong oxidizing agents
  • Highly alkaline solutions
  • Calcium-rich mixtures unless verified safe

Common (usually dose-dependent)

• Nausea, vomiting
• Headache
• Mild flushing or warmth
• Injection-site irritation
• Dizziness or lightheadedness
• Mild hypotension

Moderate

• Hepatotoxicity (elevated ALT/AST)
• Hyperuricemia / gout flare
• Insulin resistance or hyperglycemia
• GI upset

Severe / Rare

• Acute liver failure (extremely high doses)
• Thrombocytopenia
• Anaphylactoid reactions (very rare)
• Severe hypotension during rapid IV infusion

Monitoring Requirements for IV Use

• Liver function tests (especially with repeated or high-dose use)
• Renal function
• Blood glucose in diabetic patients

Blood pressure during infusion

Pregnancy

• Niacinamide is generally considered safe in pregnancy when used in standard nutritional doses.
• High-dose IV therapy has not been extensively studied, and should only be administered if medically necessary.
• Animal studies do not show teratogenicity at standard doses.

Breastfeeding

• Niacinamide is excreted into breast milk in small amounts.
• Standard doses are considered compatible with breastfeeding.
• High or therapeutic IV doses should be used with caution and require risk-benefit evaluation.

• Store vials at controlled room temperature: 20–25°C (68–77°F)
• Protect from light to prevent degradation
• Do not freeze
• Use only clear solutions—discard if cloudy, tinted, or particulate matter present
• Use single-dose vials promptly after opening (if not preservative-free)
• Follow manufacturer-specific storage recommendations

(Professional medical & pharmacologic sources)

1. NIH Office of Dietary Supplements. Niacin Fact Sheet – National Institutes of Health
2. Lexicomp Online / UpToDate – Niacinamide drug monograph
3. Micromedex (IBM Watson) – Niacinamide injectable formulation data
4. American Society for Parenteral and Enteral Nutrition (ASPEN) – Parenteral vitamin guidelines
5. Carpenter KJ. Niacin. Academic Press.
6. World Health Organization (WHO). Parenteral Nutrition Guidelines.
7. Chan AY. Adverse effects of high-dose niacin therapy. Clin Pharmacol Ther.