Magnesium Ascorbyl Phosphate

Magnesium Ascorbyl Phosphate is a stable vitamin C derivative typically used around 1–10% in leave-on products, and it is generally better tolerated than low-pH L-ascorbic acid because it does not require an acidic formulation to function. Clinical and consumer data suggest low rates of stinging and erythema, but irritation can still occur in compromised barriers (eczema, post-procedure) or when layered with other actives, so it is best classified as gentle rather than very gentle. Safety Notes: In commercial products, Magnesium Ascorbyl Phosphate (a stable vitamin C derivative) is often used at very low levels (~0.05–0.5%) in multi-ingredient brightening moisturizers/cleansers where it serves as a supporting antioxidant and label claim component, with leave-on serums and lotions more commonly landing around 1–5% based on both market practice and published efficacy testing. High-strength consumer-available leave-on treatments and “vitamin C derivative” serums can reach 10% and, more rarely, ~15% MAP, typically requiring higher-pH aqueous gel/cream systems for solubility and stability; rinse-off formats generally sit toward the low end due to short contact time.