Niacinamide

Chemical Name: 3-Pyridinecarboxamide

Alternative Names: Vitamin B3, Vitamin PP

CAS: 98-92-0

Appearance: White granular or crystalline powder, odorless or nearly odorless, with a bitter taste.

Physical and Chemical Properties:

Melting Point: 128~131℃

Boiling Point: 150~160℃ (at 0.07 kPa)

Flash Point: 182℃

Relative Density (water=1): 1.08 (at 25℃)

Solubility: Easily soluble in water, ethanol, sodium carbonate solution, and sodium hydroxide solution; soluble in glycerol; almost insoluble in ether.

Applications

I. Skincare

Improving Skin Barrier Function

Mechanism: Promotes ceramide synthesis, enhances the water-retention capacity of the stratum corneum, and reduces transepidermal water loss.

Target Population: Patients with atopic dermatitis, dry skin, or ichthyosis.

Efficacy: Long-term use alleviates desquamation, pruritus, and tightness, with noticeable effects requiring over 8 weeks of continuous application.

Recommended Combination: Use in conjunction with moisturizers such as urea cream or petroleum jelly to enhance barrier repair efficacy.

Regulating Sebum Secretion and Oil Control for Acne Treatment

Mechanism: Inhibits sebocyte proliferation and triglyceride synthesis to balance sebum production.

Target Population: Individuals with oily skin or mild-to-moderate acne.

Efficacy: Clinical data show that 4% niacinamide gel reduces inflammatory acne lesions by approximately 50% after 8 weeks, with oil-control efficacy comparable to 2% salicylic acid but milder in nature.

Recommended Combination: Patients with seborrheic dermatitis should use it alongside antifungal agents and avoid standalone application.

Lightening Hyperpigmentation and Whitening

Mechanism: Blocks melanosome transfer to keratinocytes, inhibits tyrosinase activity, and reduces UV-induced pigmentation.

Target Population: Patients with melasma, post-inflammatory hyperpigmentation, or acne scars.

Efficacy: 2–4% niacinamide serum achieves an efficacy rate for pigmented lesions comparable to 4% hydroquinone, requiring 3–6 months of continuous use.

Recommended Combination: Combining with vitamin C derivatives enhances antioxidant effects; sensitive skin should start with low concentrations (e.g., 2%) to build tolerance.

Anti-Inflammatory, Soothing, and Repairing

Mechanism: Suppresses the release of inflammatory cytokines such as tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), alleviating erythema and pruritus.

Target Population: Patients with rosacea, atopic dermatitis, or contact dermatitis.

Efficacy: Anti-inflammatory potency equivalent to 1% clindamycin, suitable for individuals intolerant to antibiotics.

Recommended Combination: Requires adjunctive pulsed dye laser therapy when telangiectasia is present.

Anti-Photoaging and Anti-Wrinkle

Mechanism: Repairs UV-induced DNA damage, reduces matrix metalloproteinase (MMP) production, and promotes collagen synthesis.

Target Population: Individuals with photodamaged skin exhibiting laxity, wrinkles, or pigmentation.

Efficacy: When paired with sunscreen during the day, it improves signs of photoaging.

Recommended Combination: Anti-aging serums containing niacinamide are often formulated with retinol or peptides.

II. Adjunctive Disease Treatment

Photosensitive Skin Disorders

Applicable Conditions: Polymorphic light eruption, chronic actinic dermatitis.

Efficacy: 5% niacinamide gel reduces UV-induced inflammatory responses, minimizing erythema and edema.

Recommended Combination: Strict sun protection and avoidance of UV exposure are essential.

Metabolic Disorders

Hypertriglyceridemia: Inhibits adipose tissue lipolysis, reduces free fatty acid transport to the liver, and lowers very-low-density lipoprotein (VLDL) synthesis.

Diabetes: Participates in glucose metabolism as a precursor to coenzymes I/II, improving insulin sensitivity but not replacing hypoglycemic medications.

Recommended Combination: Requires medical supervision, with monitoring of liver function and blood glucose levels.

Pellagra (Niacin Deficiency)

Symptoms: The classic triad of dermatitis, diarrhea, and dementia.

Efficacy: Corrects coenzyme I deficiency to rapidly alleviate symptoms, necessitating adjunctive oral vitamin B complex tablets and dietary adjustments (e.g., reducing corn-based staples).

III. Systemic Health Management

Neurological Support

Mechanism: Participates in energy metabolism to maintain brain and neural tissue health.

Target Population: Patients with anxiety or depression (requires adjunctive psychotherapy and medications).

Efficacy: May improve mood by elevating dopamine levels, though evidence remains limited.

Cardiovascular Protection

Mechanism: Lowers low-density lipoprotein cholesterol (LDL-C) and raises high-density lipoprotein cholesterol (HDL-C).

Target Population: Patients with hypercholesterolemia (requires adjunctive statin therapy).

Precautions: Long-term high-dose use (>500 mg/day) may induce hepatotoxicity.