Can I use Serum 20 AOX+ if I'm new to vitamin C?

This is a high-potency formula best for experienced vitamin C users. If you're new to vitamin C, we recommend starting with CE Ferulic (15% L-ascorbic acid) and building tolerance before advancing to Serum 20 AOX+.

Why does the serum sometimes appear darker in color?

L-ascorbic acid naturally oxidizes when exposed to light, air, and heat, causing the serum to darken from clear to yellow or brown. While still safe to use when slightly yellow, replace the product if it turns dark brown as potency will be significantly reduced.

Can I layer this with other active ingredients?

Yes, but introduce carefully. Use vitamin C in the morning and reserve retinoids for evening. You can layer with niacinamide and hyaluronic acid, but avoid mixing with benzoyl peroxide or AHA/BHA products in the same application.

How long before I see results?

Most patients notice improved skin brightness within 2-4 weeks of consistent use. Significant improvements in dark spots, texture, and fine lines typically become visible after 6-8 weeks of daily application with proper sun protection.

Serum 20 AOX+ — SkinCeuticals

Name: Serum 20 AOX+
Brand: SkinCeuticals
Availability: InStock

About Serum 20 AOX+

Serum 20 AOX+ represents SkinCeuticals' most potent vitamin C formulation, delivering 20% pure L-ascorbic acid in a stabilized aqueous solution. This clinical-grade antioxidant serum provides comprehensive environmental protection while promoting collagen synthesis and cellular turnover for visibly brighter, more even-toned skin. The high-concentration formula penetrates deeply to neutralize free radicals from UV exposure, pollution, and infrared radiation that contribute to premature aging. With consistent use, this powerhouse serum helps diminish the appearance of fine lines, improve skin texture, and restore radiance to photodamaged skin. Best suited for experienced vitamin C users with normal to oily skin types who can tolerate higher concentrations of active ingredients.

Key Ingredients

20% L-Ascorbic AcidZinc SulfateTyrosineSodium Hyaluronate

How to Use

Apply 4-6 drops to clean, dry skin every morning after cleansing and toning. Gently pat into face, neck, and chest, avoiding the eye area. Allow to absorb for 10-15 minutes before applying moisturizer and sunscreen. Start with every other day if new to high-concentration vitamin C, gradually building to daily use as tolerated. Always follow with broad-spectrum SPF 30 or higher.

Pro Tip from Our Clinicians

Store in a cool, dark place and use within 3-4 months of opening to maintain potency. This serum pairs beautifully with our HydraFacial treatments - apply post-facial for enhanced penetration and results. If experiencing irritation, alternate with SkinCeuticals CE Ferulic for a gentler vitamin C experience.

Best For Skin Types

normalcombinationoily

Targets

dullnessdark spotsfine linestexturepost inflammatorysun protection

Pairs Well With

hydrafacial peels ipl skiniq

Serum 20 AOX+

About Serum 20 AOX+

Key Ingredients

How to Use

Best For Skin Types

Targets

Pairs Well With

Frequently Asked Questions

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