At a glance
- CAS number
- 50-81-7
- INCI name
- Ascorbic Acid
- Function
- antioxidant, active, ph_adjuster
- Typical use level
- 0.5%–20%
- Solubility
- water
- Stable pH
- 2.5–3.5
CAS number and synonyms are sourced from PubChem. Function, usage levels, pH and compatibility are AI-assisted formulation guidance — verify against your supplier's technical data sheet and applicable regulations before use.
Also known as
l-ascorbic acid ascorbic acid vitamin C L(+)-Ascorbic acid Ascoltin Ascorbicap Cevitamic acid Allercorb Ascorbajen Ascorin Ascorteal Ascorvit
Compatibility
Works well with:
Ferulic Acid Vitamin E (Tocopherol) Niacinamide (low conc.) Hyaluronic Acid Panthenol Glycerin Zinc Sulfate
Use caution with:
Niacinamide (high conc.) Benzoyl Peroxide Retinol Copper Peptides Alkaline pH ingredients Oxidizing agents Iron salts
Ascorbic Acid is highly unstable and oxidizes rapidly above pH 3.5 or when exposed to light, heat, and metal ions such as iron or copper, which catalyze degradation. High concentrations of Niacinamide can potentially form a yellow nicotinic acid complex, though this is debated at typical cosmetic use temperatures. Ferulic Acid and Tocopherol are classic synergistic partners that significantly improve oxidative stability.
Formulation notes
Effective vitamin C form for skin brightening and collagen synthesis, but formulation is challenging due to instability; use antioxidant boosters, opaque packaging, and keep pH below 3.5. Concentrations above 20% offer diminishing returns and may increase irritation risk. No regulatory maximum in most markets, but patch testing recommended at higher levels.
Related ingredients
- AstaxanthinAntioxidant
- TocopherolAntioxidant
- Tocopheryl AcetateAntioxidant
- Azelaic AcidActive
- BakuchiolActive
- BisabololActive