Compatibility of Niacinamide and Vitamin C

Regarding the compatibility of Niacinamide (Vitamin B3) with Vitamin C (L-ascorbic acid) and Ascorbyl Glucoside (AA-2G), here's an explanation based on the properties of these ingredients:

Niacinamide and L-Ascorbic Acid

Mixing Niacinamide and L-ascorbic acid in the same formula is generally not recommended. The primary reason is the difference in their optimal pH ranges for stability and efficacy. L-ascorbic acid is most stable and effective in acidic environments, typically at a pH of 3.5 or lower. Niacinamide, on the other hand, is most stable in a neutral pH range (around 4.0-7.0). When mixed, the resulting pH can cause L-ascorbic acid to degrade, potentially reducing its antioxidant and skin-brightening benefits. While some sources suggest they can be used together, it often requires careful formulation or applying them at different times to avoid this interaction.

Niacinamide and Ascorbyl Glucoside (AA-2G)

Ascorbyl Glucoside (AA-2G) is a stabilized derivative of Vitamin C. While it is more stable than L-ascorbic acid, its optimal stability is within a specific pH range, typically around 6.5-6.8. According to product information, mixing Niacinamide with Ascorbyl Glucoside (AA-2G) is not recommended as it can affect the stability of AA-2G.

Conclusion

Based on the stability requirements and potential interactions, it is generally advised against mixing Niacinamide with either L-ascorbic acid or Ascorbyl Glucoside (AA-2G) in the same formulation to ensure the best efficacy and stability of the ingredients. If you wish to use both Niacinamide and a form of Vitamin C, consider using different derivatives of Vitamin C that are more compatible with Niacinamide's optimal pH, or apply the products separately at different times of the day.