Head to Head
Peter Thomas Roth Potent-C Power Serum vs Sunday Riley C.E.O. Brightening Serum
Two THD ascorbate serums compared on the numbers: 20 percent with declared vitamin E and ferulic acid, against 15 percent built for glow and comfort.
Peter Thomas Roth Potent-C Power Serum
The fullest ferulic formula in this edit: 20 percent THD ascorbate, backed by vitamin E and ferulic acid at declared levels.
Sunday Riley C.E.O. 15% Vitamin C Brightening Serum
A glow first THD ascorbate serum cushioned with squalane and a phytosterols complex, made to feel kind on skin.
Where They Differ
Strength and the supporting cast
Potent-C prints 20 percent THD ascorbate with 3 percent vitamin E and 2 percent ferulic acid, the fullest published specification in this edit. C.E.O. prints 15 percent THD ascorbate and supports it with a phytosterols complex and squalane, a comfort cast rather than an antioxidant cast. The difference is philosophical as much as numerical: one formula maximises the antioxidant system, the other optimises tolerance and feel.
Texture, scent and the morning ritual
Potent-C is fragrance free and rich, a light lotion texture that normal and dry skin read as nourishment. C.E.O. is a lighter emulsion with an immediate luminous finish and a clear citrus scent from orange and tangerine peel oils. Oily skin tends to prefer the C.E.O. finish in warm weather; fragrance avoiders have only one candidate in this pairing.
Who finishes the bottle
Both are pumps, both are 30 ml, and both are stable forms that spare owners the oxidation watch. The practical split is adherence: Potent-C suits the reader who values a routine that feels clinical and complete, C.E.O. suits the reader whose consistency depends on pleasure. Either is a defensible daily driver; neither asks for refrigeration, layering tricks or a tolerance building programme.
The Specification, Side by Side
| Measure | Peter Thomas Roth Potent-C Power Serum | Sunday Riley C.E.O. 15% Vitamin C Brightening Serum |
|---|---|---|
| Vitamin C Form | THD Ascorbate, 20 percent | THD Ascorbate, 15 percent |
| Key Supporting Actives | Vitamin E 3 percent, Ferulic Acid 2 percent, Squalane | Phytosterols Complex, Squalane, Glycolic Acid |
| Size | 30 ml / 1 fl oz | 1.0 fl oz / 30 ml |
| Format | Pump serum, fragrance free | Pump serum |
| Model | 15-01-049, as printed on the listing | Not published |
| Scent | Not published | Citrus, from orange and tangerine peel oils in the ingredient list |
Choose Peter Thomas Roth Potent-C Power Serum if
- You want the highest declared THD ascorbate level and printed vitamin E and ferulic acid levels
- You avoid fragrance in skincare entirely
- Your skin is normal to dry and likes a richer serum texture
Choose Sunday Riley C.E.O. 15% Vitamin C Brightening Serum if
- You judge a brightening serum by the glow in the first minute
- Pure vitamin C serums have felt too sharp, and comfort decides your consistency
- You enjoy scented, sensorial products and citrus in particular
Questions, Answered
Is 20 percent THD ascorbate meaningfully stronger than 15 percent?
On paper, yes; on skin, the gap is smaller than the numbers suggest, because form, base and daily consistency all mediate the result. Treat the percentages as a guide to intent: Potent-C is formulated as the maximal option, C.E.O. as the balanced one. A serum used every morning at 15 percent serves most readers better than a stronger one used sporadically.
Keep Researching
Every page in the Vitamin C Serums edit.
- 01Vitamin C Serums: the hubHub
- 02Best Vitamin C Serums 2027Best of
- 03Vitamin C Serums for Sensitive SkinGuide
- 04Vitamin C Serums for the Look of Dark SpotsGuide
- 05Vitamin C and Ferulic Acid SerumsGuide
- 06Peter Thomas Roth Potent-C Power Serum ReviewReview
- 07Sunday Riley C.E.O. 15% Vitamin C Brightening Serum ReviewReview
- 08Obagi Professional-C Serum 20% ReviewReview
- 09La Roche-Posay Pure Vitamin C12 Serum vs Caudalie Vinoperfect Brightening SerumComparison
- 10Vitamin C Serums Buying GuideBuying guide
- 11Vitamin C Serum Care and KeepingCare
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