The skincare ingredient derived from vitamin B3 that improves the skin barrier is niacinamide. Also called nicotinamide, it is the amide form of vitamin B3 and is widely used in topical skincare.
Niacinamide supports the epidermal permeability barrier partly by increasing the production of ceramides and other lipids in the outer skin layer. A stronger barrier helps reduce water loss and can make skin less vulnerable to dryness and irritation. It is also used in products aimed at acne, redness, uneven pigmentation, and signs of aging.
A common mix-up is niacin, another form of vitamin B3. Niacin can cause skin flushing, while niacinamide generally does not produce that effect at ordinary topical concentrations. The ingredient is not the same as vitamin C, retinol, or hyaluronic acid: those ingredients have different roles, even though they may appear in the same formula.
Niacinamide is also a nutrient used to prevent or treat niacin deficiency. In skincare, its versatility and generally good tolerability have made it a common ingredient in serums, moisturizers, and barrier-repair creams.