We carry four SkinCeuticals vitamin C serums, and at first glance they look alike: a small bottle, a few drops each morning, antioxidant support for a brighter-looking complexion. The differences are in the details: how much vitamin C each one contains, what it is paired with, the finish it leaves and the skin type it is made for. This guide puts all four side by side, using the ingredient percentages listed for each product.
The short answer
- Normal, dry or combination skin: SkinCeuticals C E Ferulic, with 15% vitamin C, vitamin E and ferulic acid.
- Normal, combination or oily skin that dislikes shine: SkinCeuticals Phloretin CF, with 10% vitamin C, phloretin and a dry-touch finish.
- Oily, combination or blemish-prone skin: SkinCeuticals Silymarin CF, with 15% vitamin C, silymarin, salicylic acid and a matte finish.
- New to vitamin C, or skin that feels sensitive: SkinCeuticals Serum 10 AOX+, with 10% vitamin C at a gentler strength.
The four serums side by side
| Serum | Vitamin C (L-ascorbic acid) | Paired with | Made for | Finish and feel |
|---|---|---|---|---|
| C E Ferulic | 15% | Vitamin E (alpha-tocopherol) 1%, ferulic acid 0.5% | Normal, dry and combination skin, including skin that feels sensitive | Faint citrus-like scent that fades within minutes |
| Phloretin CF | 10% | Phloretin 2%, ferulic acid 0.5% | Normal, combination and oily skin, including skin prone to the look of dark spots | Lightweight, dry-touch finish that adds no shine |
| Silymarin CF | 15% | Silymarin 0.5%, ferulic acid 0.5%, salicylic acid 0.5% | Oily, combination and blemish-prone skin | Matte finish; faint scent that fades within minutes |
| Serum 10 AOX+ | 10% | Ferulic acid 0.2% | First-time vitamin C users and skin that feels sensitive | Low-pH formula (under 3.5) |
All four are used the same way: 4 to 5 drops on clean, dry skin each morning, before moisturizer and SPF.
What the four have in common
Each serum is built on L-ascorbic acid, the pure form of vitamin C. Vitamin C is an antioxidant, and in these formulas it gives antioxidant support against daily environmental stressors for a brighter-looking complexion. Each one also contains ferulic acid. In C E Ferulic, ferulic acid is there to help stabilize vitamins C and E and support their antioxidant performance.
Pure vitamin C is sensitive to light, heat and air, so storage matters. Close the bottle tightly after each use and keep it away from direct light and heat. The directions for Serum 10 AOX+ put it plainly: if the color shifts from clear yellow to deep orange or brown, stop using it.
C E Ferulic: 15% vitamin C with vitamin E
C E Ferulic combines 15% L-ascorbic acid with 1% vitamin E and 0.5% ferulic acid. It is a daytime antioxidant serum for a brighter-looking tone and softer-looking fine lines, and it suits normal, dry and combination skin, including skin that feels sensitive.
Expect a faint citrus-like scent that fades within minutes. It is made for the morning routine, layered under moisturizer and SPF, and the bottle should be stored away from direct light and heat.
Choose it if your skin is normal to dry and you want the 15% formula with vitamin E.
Phloretin CF: 10% vitamin C with phloretin
Phloretin CF pairs 10% L-ascorbic acid with 2% phloretin, a flavonoid derived from apples, and 0.5% ferulic acid. It is made for normal, combination and oily skin, and for complexions prone to the look of dark spots and uneven-looking tone.
The texture is lightweight with a dry-touch finish, so it layers cleanly under SPF and makeup without adding shine.
Choose it if you want a daytime antioxidant that doesn't feel heavy or add shine.
Silymarin CF: 15% vitamin C for oily and blemish-prone skin
Silymarin CF pairs 15% L-ascorbic acid with 0.5% silymarin, an antioxidant derived from milk thistle, 0.5% ferulic acid and 0.5% salicylic acid. It is formulated for oily, combination and blemish-prone skin. It helps limit the oxidation of skin's natural oils, which can contribute to the look of blemishes, and supports a clearer-looking complexion over time.
It leaves a matte finish that layers under makeup without shine or pilling. Like C E Ferulic, it has a faint scent that fades within minutes.
Choose it if your skin is oily or blemish-prone, or you have occasional blemishes alongside early visible signs of aging.
Serum 10 AOX+: the gentler place to start
Serum 10 AOX+ uses 10% L-ascorbic acid with 0.2% ferulic acid, formulated at a low pH (under 3.5). It is made at a gentler concentration for first-time vitamin C users and skin that feels sensitive, and gives daily antioxidant support while your skin adjusts.
Skin adjusts over a period of weeks. Once your tolerance is established, you may choose to move up to a 15% formula, such as C E Ferulic or Silymarin CF, after several months.
Choose it if you are new to vitamin C or your skin feels sensitive.
How to use a vitamin C serum
- Cleanse and pat your skin dry. All four serums go on clean, dry skin.
- Apply 4 to 5 drops in the morning.
- Follow with moisturizer, then SPF as the last step.
- Close the bottle tightly and store it away from light and heat.
With retinol: keep vitamin C in the morning and retinol in the evening. If both are new to you, add one at a time, so you can see how your skin responds to each. Vitamin C, retinol and peptides explains how the two fit together.
With a hydrating gel: SkinCeuticals Hydrating B5 Gel is made to layer under a vitamin C routine. Because the vitamin C serums ask for dry skin, give the gel a moment to sink in first.
Common questions
Which is strongest?
C E Ferulic and Silymarin CF contain 15% L-ascorbic acid; Phloretin CF and Serum 10 AOX+ contain 10%. Strength is only one difference: the ingredients paired with the vitamin C, and the finish, change too.
Can I use them at night?
All four are described as morning serums, applied under moisturizer and SPF. The evening is a good time for retinol or other actives instead.
Why does my serum have a scent?
C E Ferulic has a faint citrus-like scent, and Silymarin CF a faint characteristic scent. Both fade within minutes.
How do I know if a serum has oxidized?
Watch the color. If Serum 10 AOX+ shifts from clear yellow to deep orange or brown, stop using it. Storing any vitamin C serum tightly closed and away from light and heat helps.
Other ways to add vitamin C
- In a moisturizer: Hydrinity Hydri-C Daily Vitamin C Moisturizer uses ethyl ascorbic acid, a vitamin C derivative that is stable in a cream base, with Hydrinity's HA complex, niacinamide and peptides. It is an easy first step if you are new to vitamin C, applied every morning before SPF.
- In a hydrating serum: Hydrinity Renewing HA Serum pairs stabilized vitamin C with Hydrinity's HA complex, peptides and niacinamide, for morning and evening use.
How to choose
- New to vitamin C, or skin that feels sensitive: start with Serum 10 AOX+, and consider a 15% formula after several months.
- Normal, dry or combination skin: C E Ferulic.
- Normal, combination or oily skin, or skin prone to the look of dark spots: Phloretin CF.
- Oily or blemish-prone skin: Silymarin CF.
- Prefer a cream to a serum: Hydri-C.
Browse all vitamin C skincare, the full SkinCeuticals range, the SkinCeuticals vitamin C shelf or our serums. For where vitamin C sits among your other steps, see how to layer skincare.
Related guides: retinol strengths explained and hyaluronic acid serums compared.