Vitamin C (L-Ascorbic Acid)
AntioxidantBrighteningVitaminNaturalAlso known as: L-Ascorbic Acid, Ascorbic Acid, LAA, Ascorbyl Glucoside, Sodium Ascorbyl Phosphate, Magnesium Ascorbyl Phosphate
A powerful antioxidant that brightens skin, boosts collagen production, and protects against environmental damage including UV and pollution.
Routine placement
Serum · AM
Time to results
4-6 weeks for brighter tone; 8-12 weeks for dark spots
Brightens skin tone, fades hyperpigmentation, boosts collagen production, protects against UV damage and pollution, evens skin tone.
Apply in the morning before sunscreen. L-Ascorbic Acid works best at pH 2.5-3.5 and concentrations of 10-20%. Store in a dark, cool place to prevent oxidation.
Beginner
5-10%
Intermediate
15%
Advanced
20%
Robust evidence for photoprotection, collagen synthesis, and hyperpigmentation treatment. L-Ascorbic Acid at 10-20% with Vitamin E and Ferulic Acid shows synergistic antioxidant benefits.
Key Studies
Topical vitamin C and the skin (2017)
J Clinical and Aesthetic Dermatology
L-ascorbic acid 10-20% provides photoprotection and stimulates collagen. pH below 3.5 required.
Antioxidants in photoprotection (2003)
J American Academy of Dermatology
Vitamin C + E reduces UV free radical damage by up to 4x.
Vitamin C in dermatology (2013)
Indian Dermatology Online Journal
5-15% ascorbic acid promotes collagen and reduces melanin.
- very sensitive skin (start with derivatives)
Cautions
Can cause tingling or irritation at higher concentrations. L-Ascorbic Acid is unstable and oxidizes easily (turns brown/orange). May not suit very sensitive skin.
Can I use vitamin C and retinol together?
Yes, at different times. Vitamin C AM (photoprotection), retinol PM.
Why did my serum turn brown?
Oxidation from air/light/heat. Replace every 2-3 months. Store dark and cool.
What form is best?
L-ascorbic acid is most effective but unstable. Derivatives are more stable but less potent.
Do I need sunscreen with vitamin C?
Yes. Vitamin C boosts photoprotection but is not a sunscreen replacement.
Does your skincare contain Vitamin C (L-Ascorbic Acid)?
Paste your product's ingredient list to check, or create your Skinularity ID for a full routine.
Find Vitamin C (L-Ascorbic Acid) products
Browse skincare products containing Vitamin C (L-Ascorbic Acid).
Related to Vitamin C (L-Ascorbic Acid)
An extract from the yuzu citrus fruit, popular in J-beauty. Rich in vitamin C, hesperidin, and limonene.
A versatile form of Vitamin B3 that strengthens the skin barrier, reduces pore appearance, controls oil production, and addresses multiple skin concerns.
A fat-soluble antioxidant that protects cell membranes from oxidative damage. Works synergistically with Vitamin C for enhanced photoprotection.
A naturally occurring dicarboxylic acid with antibacterial, anti-inflammatory, and antioxidant properties. Effective for acne, rosacea, and hyperpigmentation.
The provitamin form of Vitamin B5 that deeply hydrates and helps repair the skin barrier. Converts to pantothenic acid in the skin.