SkinCeuticals C E Ferulic vs Obagi Professional-C 20%: Vitamin C Serums Compared by Ingredients
SkinCeuticals C E Ferulic and Obagi Professional-C Serum 20% are two well-known L-ascorbic acid serums. How their ingredients, strength, skin-type fit and use differ.
SkinCeuticals C E Ferulic and Obagi Professional-C Serum 20% are both L-ascorbic acid (pure vitamin C) serums sold mainly through dermatology offices and skincare retailers. The short answer: C E Ferulic combines 15% vitamin C with vitamin E and ferulic acid and is fragrance-free; Obagi's serum has 20% vitamin C with hyaluronic acid, contains fragrance and alcohol, and is positioned for normal to oily skin. Which fits depends on your skin, not on a "winner."
Side by side
| Feature | SkinCeuticals C E Ferulic | Obagi Professional-C 20% |
|---|---|---|
| Vitamin C form and % | 15% L-ascorbic acid | 20% L-ascorbic acid (plus ascorbyl glucoside) |
| Antioxidant partners | 1% vitamin E, 0.5% ferulic acid; brand lists added carnosine and endophytol | Orange peel and grapefruit extracts |
| Hydrator | Not a headline ingredient | Sodium hyaluronate |
| Fragrance | Brand says fragrance-free | Contains fragrance |
| Alcohol | Brand says alcohol-free | Contains alcohol denat. |
| Brand's target skin type | All | Normal to oily |
Ingredient details come from each brand's product page (SkinCeuticals; Obagi). Formulas change, so check the current packaging.
What's in C E Ferulic
SkinCeuticals lists 15% L-ascorbic acid, 1% alpha tocopherol and 0.5% ferulic acid, and says its updated formula adds 0.3% carnosine and 1% endophytol. It's labeled fragrance-, alcohol- and silicone-free.
May suit: dry, normal or sensitive-to-fragrance skin; people who want the vitamin C, E and ferulic combination.
What's in Obagi Professional-C 20%
Obagi's ingredient list starts with propylene glycol, water and ascorbic acid, followed by denatured alcohol, ascorbyl glucoside, sodium hyaluronate, citrus extracts and fragrance. Obagi notes some users may feel slight tingling.
May suit: normal to oily skin; people who don't react to fragrance and want a higher L-ascorbic acid percentage.
Does a higher percentage mean better results?
Not necessarily. Higher concentrations can increase irritation. Research on topical vitamin C supports antioxidant and brightening effects, but evidence comparing specific percentages head to head is limited.
How to use either one
- Apply a few drops to clean, dry skin in the morning.
- Follow with moisturizer and broad-spectrum sunscreen (AAD: sunscreen FAQs).
- Start every other day if you have sensitive skin.
- Store away from heat and light; discard if the serum turns dark brown.
- Patch test, especially with fragrance sensitivity.
The research behind each formula style
- Ferulic acid combination (the C E Ferulic style): Lab research found that adding ferulic acid to 15% L-ascorbic acid and 1% vitamin E made the vitamins more chemically stable and roughly doubled protection against simulated sunlight on skin, from about 4-fold to 8-fold, measured by redness and sunburn cells (Lin et al., J Invest Dermatol, 2005).
- Higher concentration (the 20% style): In pig-skin studies, L-ascorbic acid had to be formulated at a pH below 3.5 to get into the skin, and absorption peaked at about 20%. Skin levels were saturated after three daily applications. Derivatives such as magnesium ascorbyl phosphate didn't raise skin vitamin C levels in that model (Pinnell et al., Dermatol Surg, 2001).
These are lab and animal findings, not head-to-head trials of the two products. Both brands use L-ascorbic acid, the form those studies tested.
Frequently asked questions
Which is stronger? Obagi's has a higher listed L-ascorbic acid percentage (20% vs 15%), but strength isn't the only factor.
Can I use either with retinol? Yes; vitamin C in the morning, retinol at night.
Is either better for sensitive skin? The fragrance-free formula may be easier for fragrance-sensitive skin; patch test either way.
This article is for educational purposes only and is not medical advice. We have no commercial relationship with either brand, and this comparison is not sponsored. Talk to your dermatologist about your situation.
Sources
- SkinCeuticals. C E Ferulic product page
- Obagi. Professional-C Serum 20% product page
- American Academy of Dermatology. Sunscreen FAQs
