Vitamin C Serums: What Strength Should You Use?
Vitamin C Concentrations
L-ascorbic acid is a top anti-aging ingredient, but concentration matters.
5-10%: Sensitive/Beginner
Start here for reactive skin. Antioxidant protection with minimal irritation.
10-15%: Normal/Combination
The sweet spot. Visible brightening and collagen boosting.
15-20%: Experienced
Maximum effective concentration. 20% is the saturation point — higher adds no benefit.
Beyond Concentration
- pH below 3.5 for penetration
- L-ascorbic acid (potent) vs sodium ascorbyl phosphate (gentler)
- Dark, airtight bottles prevent oxidation
- Vitamin E + ferulic acid boost effectiveness 8x
Introduction Schedule
Week 1-2: every other day. Week 3-4: daily. Week 5+: AM and PM if tolerated. Always SPF.
