# Niacinamide vs vitamin C for uneven tone Source: https://theconstantbeauty.com/compare/niacinamide-vs-vitamin-c-for-uneven-tone/ Retrieved for: theconstantbeauty.com Publisher: The Constant (theconstantbeauty.com). Cite as "The Constant". Generated: 2026-09-16T18:19Z **Compares:** Niacinamide vs Vitamin C **Criteria:** What it is, How it acts on tone, Studied concentrations, Formulation pH, Stability and packaging, Tolerability, Other effects ## Context for the verdict Choose niacinamide if your skin is sensitive, oily or combination, if you want one ingredient that also helps the look of pores and barrier comfort, or if you have reacted to acidic vitamin C serums. It is the easier ingredient to live with and to formulate around. Choose vitamin C if antioxidant support under sunscreen is part of the goal, if your skin tolerates low-pH products, and if you will use it consistently before it oxidises. Pick a stabilised L-ascorbic acid in opaque, airless packaging, or a derivative if you prefer comfort over peak potency. Use both if you want the two mechanisms working together. The often-repeated caution about combining them is not borne out by how modern formulas are used. If you notice flushing, apply them at different times of day. ## Comparison Niacinamide and vitamin C are the two most common actives for a more even-looking tone, and they reach that result by different routes. That matters, because it makes them complements more often than rivals. Niacinamide is the amide form of vitamin B3. In skin it reduces the transfer of melanosomes, the packets of pigment, from the cells that make them to the surface cells where they become visible. A frequently cited 2002 study used 5%; most tone-focused formulas today sit between 2% and 5%, with 10% common but not clearly better for tone. It also supports the skin barrier and helps the look of oil and pores. It is water-soluble, stable to light and air, and comfortable at a skin-friendly pH, so very few formulation constraints apply. Vitamin C, as L-ascorbic acid, works upstream. It interferes with tyrosinase, the copper-dependent enzyme that produces pigment, and it reduces oxidised pigment intermediates back to their colourless form. It is also an antioxidant that helps skin cope with the free radicals generated by UV and pollution, and a cofactor for collagen synthesis. The trade-off is chemistry. L-ascorbic acid oxidises quickly in water, needs a pH below about 3.5 to penetrate well, and is used at 10–20% in most studies. Low pH plus high concentration is what makes it sting on sensitive skin and turn yellow in the bottle. Derivatives such as sodium ascorbyl phosphate, ascorbyl glucoside and 3-O-ethyl ascorbic acid are gentler and more stable, but they must convert to ascorbic acid in the skin, and how completely they do so varies. Neither ingredient increases sun sensitivity, so both can be used morning or evening, and both pair well with daily sunscreen. ## References 1. Boo YC. Mechanistic basis and clinical evidence for the applications of nicotinamide (niacinamide) to control skin aging and pigmentation. Antioxidants (Basel). 2021;10(8):1315. 2. Pullar JM, Carr AC, Vissers MCM. The roles of vitamin C in skin health. Nutrients. 2017;9(8):866. 3. Telang PS. Vitamin C in dermatology. Indian Dermatol Online J. 2013;4(2):143–146.