Start with your skin type and goals, then pick the suitable La Roche-Posay Pure Vitamin C Serum variant: choose Pure Vitamin C10 Serum for a classic brightening boost on normal to combination skin, or choose Pure Vitamin C Light for a lighter, fast-absorbing feel on oily or sensitive skin. Consider bottle size to fit your routine, with options available in both 30ml and 40ml styles.

The concentration and stability of vitamin C are the key, most complex attributes. La Roche-Posay Pure Vitamin C10 Serum uses a stable vitamin C formulation that resists oxidation, while the Pure Vitamin C Light variant emphasizes a lighter texture; in practice, this means you should store the serum away from light and air, apply it to clean, dry skin, and follow with moisturizer and sunscreen for best results.

Beginners should patch test first and start with a few applications per week, applying the serum after cleansing and before moisturizer, then wearing sunscreen during the day. Pros can use the serum daily as part of the morning routine, layering it under moisturizer and sunscreen, and be mindful not to overload with other active acids at the same time.

Keep the bottle tightly closed and store it in a cool, dark place to minimize oxidation. Layer the serum with sunscreen and moisturizer, and avoid using strong actives at the same time (for example, with certain retinoids or benzoyl peroxide) unless advised. Always patch test when trying a new La Roche-Posay Vitamin C product and follow product-specific guidelines.

Pure Vitamin C Light is typically gentler and better suited for sensitive or reactive skin, thanks to its lighter texture. If you’re new to vitamin C, start with a small amount and patch test, then gradually increase frequency as your skin tolerates it.