How does niacinamide fade pigmentation?

Niacinamide fades pigmentation less by changing how much melanin is made than by reducing how many melanosomes, the tiny packets that carry pigment, get passed to the skin cells (Hakozaki et al., 2002). Start niacinamide at a low strength every day, and pair it with sunscreen by day. What it won't do is erase pigment that has already settled deep in the skin, or stand in for sunscreen. Without sun protection, lightened pigment is thought to darken again.

How does niacinamide fade pigmentation?

Melanin is made inside pigment cells called melanocytes, packed into small bundles called melanosomes, and handed to the surrounding skin cells. You see pigmentation when those melanosomes reach the skin cells and collect near the surface. Niacinamide fades pigmentation by reducing how many melanosomes get transferred to the skin cells (Hakozaki et al., 2002). In the lab, it had no effect on the melanin-making enzyme but cut transfer by 35–68%. People who applied it for 4 weeks saw a meaningfully larger drop in hyperpigmentation than with the same cream without niacinamide.

How is it different from other brightening ingredients?

Ingredients like vitamin C and arbutin are thought to lower the activity of tyrosinase, the enzyme that makes melanin, acting at the production stage. Niacinamide works later, on the transfer of melanin that has already been made. Because it works at a different step, niacinamide is thought to pair easily with vitamin C and arbutin. To compare the options, see brightening ingredients: what actually fades pigment?, and for the kinds of marks, see why dark spots won't fade with brightening alone.

How should you use niacinamide?

Most products land somewhere around 2 to 5 percent. A high strength can leave sensitive skin feeling irritated. Use niacinamide at a low strength, every day, consistently. Niacinamide is also thought to help the skin make the lipids its barrier needs; for more, see niacinamide and panthenol for the skin barrier. Wear sunscreen during the day, too, since lightened pigment is thought to darken again with UV.

In short: niacinamide evens tone slowly

Niacinamide reduces the transfer of melanosomes to skin cells; it cut transfer by 35–68% in the lab and lightened hyperpigmentation in people who applied it for 4 weeks (Hakozaki et al., 2002). It won't erase deep pigment at once or replace sun protection. If progress feels slow, check your sunscreen habit before swapping the ingredient out. Think of niacinamide as a slow tone-evener rather than an eraser, and use it steadily alongside sunscreen.

Things you can try today

• Start a 2 to 5 percent niacinamide at a low strength and use it daily. People who applied niacinamide for 4 weeks saw less hyperpigmentation than with the same cream without it (Hakozaki et al., 2002). After about 4 weeks, compare photos taken in the same light. If the area stings or reddens, apply it less often; if redness continues, see a dermatologist.
• If you also use vitamin C, you can layer them; if irritation worries you, use vitamin C in the morning and niacinamide at night. The order for using the two together hasn't been tested in trials. Notice whether layering them stings. If stinging lasts more than a few days, stop one; if redness doesn't settle, see a dermatologist.
• Wear sunscreen by day to protect the tone you've evened out. UV is thought to darken lightened pigment again, though this hasn't been tested together with niacinamide. Before going out, check in a mirror that your whole face is covered. If a new mark appears or a spot keeps changing shape, see a dermatologist.