What should you know about Roche-Posay vitamin C?

Topical vitamin C is an antioxidant ingredient used to support a more even-looking complexion and the appearance of dull or uneven tone. Formulas differ in concentration, acidity, packaging, and supporting ingredients, so two serums can feel very different. [Vitamin C Serum](/materials/vitamin-c-serum/) is not a treatment for every dark mark or a substitute for sunscreen. Existing irritation, eczema, rosacea, or a damaged skin barrier can make stinging more likely.

Patch-test a small area first, then apply a thin layer to clean, dry skin on an occasional morning if tolerated. Follow with moisturiser and broad-spectrum sunscreen. Keep the product closed and stored as its label advises; air, heat, and light can affect some vitamin C formulas. Avoid putting it on broken skin or close to the eyes. Introduce only one new active at a time so you can identify the cause if burning, itching, or a rash appears.

Stop the serum and rinse gently if it causes persistent burning, swelling, blistering, hives, or a spreading rash. Seek urgent help for facial swelling with breathing difficulty or eye symptoms. A dermatologist can assess stubborn pigmentation, unexplained skin changes, or irritation that continues after stopping the product.

Ask whether vitamin C suits your skin condition, how it fits with retinoids or exfoliating acids, whether your pigmentation needs a different diagnosis, and which sunscreen and moisturiser will protect your barrier during use.