Ascorbyl Glucoside

Ascorbyl glucoside is 抗坏血酸葡糖苷 (kàng huài xuè suān pú táng gān) in Chinese, often shortened to 维C葡糖苷; in Traditional Chinese it's 抗壞血酸葡糖苷. Usually labeled AA2G, it's a stable, gentle vitamin C derivative that converts to pure vitamin C inside the skin.

Pure vitamin C (L-ascorbic acid) is potent and fast-acting but very unstable (yellows within a month of opening), needs an acidic formula (pH < 3.5), and irritates sensitive skin. AA2G is 100x more stable, gentle, and neutral-pH — but weaker, taking 2-3x longer. AA2G suits steady long-term use; pure vitamin C suits short intensive pushes.

AA2G is short for L-Ascorbic Acid 2-Glucoside; the INCI name is Ascorbyl Glucoside. It's a patented ingredient from Japan's Hayashibara and shows up on skincare labels under abbreviations like AA2G and ASG.

Yes. Among vitamin C derivatives, AA2G has one of the best pregnancy safety profiles — pregnancy-friendly brightening lines from Shiseido, HABA, and others use AA2G instead of pure vitamin C.

No — this is one of AA2G's biggest advantages over pure vitamin C. Pure vitamin C (around pH 3) plus niacinamide (around pH 7) can neutralize each other and raise niacinate-conflict concerns; AA2G is already neutral-pH, fully compatible with niacinamide, and can be layered in the same step with no waiting.

2% is the clinical floor for results; 3-5% is the common effective range. Reference points: Vichy LiftActiv at 2%, SK-II GenOptics at 3%, HABA at 5%. Products that say "contains AA2G" without disclosing a percentage are usually ≤1% — limited effect.