Serum 20 AOX+ - Antioxidants
Serum 20 AOX+
Combines 20% L-ascorbic acid with ferulic acid to provide antioxidant and anti-aging benefits
30 ml
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Formulated at the precise concentration proven to deliver maximum amounts of vitamin C to the skin, Serum 20 AOX+ is designed to restore and protect healthy looking skin. This lightweight and fast-absorbing serum neutralizes free radicals, defends against environmental damage, and helps prevent the appearance of accelerated aging.
  • Helps reduce the appearance of fine lines and wrinkles, neutralizes free radicals, and defends against environmental damage
  • Using Duke-patented vitamin C technology, this serum delivers the highest level of L-ascorbic acid that can be absorbed by the skin
  • Once absorbed, this serum can't be washed or rubbed off. It remains effective for a minimum of 72 hours, making it an excellent addition to sunscreen.
clinical study
Studies show that when formulated properly (as all SkinCeuticals antioxidants are), a 20% concentration of L-ascorbic acid provides the maximum amount of vitamin C readily absorbed by the skin.
Formulated with AOX+ advanced antioxidant technology, Serum 20 combines ferulic acid with pure vitamin C at the precise pH and concentration to enhance performance and deliver maximum levels of L-ascorbic acid.
Innovation 1
L-ascorbic acid has a reservoir effect, which means it can’t be washed off or rubbed off for a minimum of 72 hours.
Innovation 2
The addition of ferulic acid enhances the antioxidant performance of vitamin C.
In the morning after cleansing, apply 4-5 drops to a dry face, neck and chest.

It is normal for vitamin C products to darken after opening due to air and light exposure. Any change in color does not affect the product's efficacy.
1: Cleanse & Tone
2: Prevent with Serum 20 AOX+
3: Correct
4: Moisturize
5: Protect
key ingredients
Key Ingredient 1
20% L-ascorbic acid (vitamin C): Neutralizes damaging free radicals and protects skin’s breakdown from oxidative stress.
Key Ingredient 2
0.2% Ferulic acid: This plant-based antioxidant neutralizes free radicals, inhibits UV-induced skin discolorations, and has anti-inflammatory properties.
Serum 20 AOX+ 5 5 4 5
Absolutely keeps wrinkles at bay! I was referred to this product about 30 years ago. My laser skin doctor recommended I begin using Vitamin C Serum. I was on the road a few thousand miles a month and suggested I always wear a hat when I'm out in the sun. She said it would keep my wrinkles from forming prematurely and boy was she right. I've had collegues, co-workers ask what I use and offer information on what Vitamin C Serum could do for them. A few began using with Serum 15 then to 20% after about 9 months. You really could see the difference almost right away. I have been told by co-workers, doctors, and skin specialists that my skin appears to have the look and texture of a 40 year old. Happy to hear this and confident to know that it's working as I was told it would. If you get to where you stop using for months, once you began using again . . . goes right to work! I love it when people ask me what I use on my face to keep it so supple and my age. One word of advice, I also don't use make-up (isn't necessary now) other than eye shadow, mascara and a little lip gloss and don't use soap and water on my face. My skin is dry and I will use a special sun screen from my doctor's office for sensitive dry skin. This is why I don't wear make-up and besides now it's not necessary the texture and skin tone is so even you don't need it. Remember you cannot stay in full sun when using this product, your skin will become sensitive to too much exposure. If you must, wear a wide brim hat, I have several hats. June 23, 2012
This product is amazing with all the benefits I love this product. I have been using skin ceuticals for the past 12 years and my skin always looks amazing and I have prevented a lot of wrinkles with the use of these products. If I could literally bathe in these products I would. October 27, 2011
Have been using 20% C for years I have been using 20% C for years and am now trying 20% C with Ferulic acid. I do not have any sun damage on face or chest. July 27, 2011
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