Sunday Riley CEO Rapid Flash Brightening Serum 01

In case you’re wondering, yes – that is a sample size of Sunday Riley C.E.O. Rapid Flash Brightening Serum.

You see, I wasn’t sure if I’d like it or not and didn’t want to fork out £70 for the privilege of finding out. So I did what I always do in these cases: wait for the holidays.

Holiday season is the best time for skincare shopping. You can bag gift sets full of a brand’s bestsellers to satisfy your curiosity – for less than half the price. If you dig everything, awesome. If you’re stuck with a dud, no harm done.

Let me tell you, I’m glad I waited. Sunday Riley C.E.O. Rapid Flash Brightening Serum has a lot going for it, but it’s no match for my new Vitamin C HG, Drunk Elephant C-Firma Day. Here’s why:

What’s In Sunday Riley C.E.O. Rapid Flash Brightening Serum?


Tetrahexyldecyl Ascorbate is a form of Vitamin C that’s oil-soluble. This matters because your skin’s protective barrier is oily, so anything water-based has a hard time getting through (it’s not impossible, just more difficult).

Its oil-soluble properties mean that Tetrahexyldecyl Ascorbate penetrates skin faster and goes in deeper than any other form of vitamin C (including L-Ascorbic Acid – the pure form).

Here’s what it does for your skin:

  • Antioxidant: It destroys the free radicals that cause premature wrinkles.
  • Brightening: It fades away discolourations by reducing the production of melanin by more than 80%.
  • Firming: It boosts the production of collagen (even more than L-Ascorbic Acid).

Awesome, right? I have two “problems” with this:

  1. Less effective than L-Ascorbic Acid: Ee know that Tetrahexyldecyl Ascorbate penetrates skin better than L-Ascorbic Acid but we don’t know if it’s just as (or more) effective. Usually, derivatives aren’t.
  2. No ferulic acid: Studies show that vitamin C is more effective when used with its BFF vitamin E and ferulic acid. This serum only has vitamin E.

If you want your skincare products to be backed up by as much science as possible, you’re better off with one that contains L-Ascorbic Acid + vitamin E + ferulic acid. Drunk Elephant C-Firma Day fits the bill.

If your skin can’t take L-Ascorbic Acid, then using products with a Vitamin C derivative like Sunday Riley C.E.O. Rapid Flash Brightening Serum makes more sense.

Related: Is Tetrahexyldecyl Ascorbate The Best Vitamin C Derivative?


Is it me or every brand is switching to squalane lately?

I totally see why. It’s one of the few oils that’s 100% safe and non-comedogenic for everyone, including people with fungal acne.

Squalane works because it’s very similar to human sebum, your skin’s natural moisturiser. In other words, your skin recognises it straight away, allowing it to sink quickly and deeply moisturise your skin.

It strengthens the skin’s protective barrier, moisturises skin and keeps it soft and smooth for hours.

Related: How To Treat Fungal Acne

Struggling to put together a skincare routine that minimises wrinkles, prevents premature aging, and gives your complexion a youthful glow? Download your FREE “Best Anti-Aging Skincare Routine” to get started (it features product recommendations + right application order):


Sunday Riley C.E.O. Rapid Flash Brightening Serum has a white, creamy texture that reminds me more of a lightweight lotion that a serum. On my dry skin, it sinks in quickly without leaving a sticky residue behind.


Technically, it’s fragrance-free. But, the orange oil gives it a citrusy scent.

How To Use It

Every morning under sunscreen to boost its sun protection.

Performance & Personal Opinion

I’ve been using Sunday Riley C.E.O. Rapid Flash Brightening Serum for a couple months and I can’t say I saw a big improvement in my skin. My skin looks a little brighter and more awake, but that’s pretty much it.

I’m confident that vitamin C is also fighting free radicals, keeping those pesky premature wrinkles off my face. But it would do it a lot better if the serum contained more antioxidants.

Overall, I’m on the fence. Sunday Riley C.E.O. Rapid Flash Brightening Serum does what every other vitamin C serum does. It just never goes the extra mile.

Five years ago, I’d have been all over it. Now the skincare market’s become so competitive, I feel like there are better options out there. This one leaves me feeling meh…

One more thing: Sunday Riley added sweet orange oil to make the serum smell like vitamin C. It’s cool and pleasant but citrus oils can irritate sensitive skin. So I’m not sure this serum is a good option even for this skin type…

Sunday Riley CEO Rapid Flash Brightening Serum 02

Who Is This For?

Sensitive skin that doesn’t react badly to citrus oils.

Who Is This NOT For?

If you’re looking for an anti-aging serum, opt for one with L-Ascorbic Acid instead of a Vitamin C derivative.


An orange bottle with a pump applicator. It makes you think of Vitamin C, is practical, and keeps Vitamin C from spoiling too soon.

Does Sunday Riley C.E.O. Rapid Flash Brightening Serum Live Up To Its Claims?

CEO 15% Vitamin C Brightening Serum, is targeted to quickly fight the look of dullness, dark spots, and discolorations at the source, while diminishing the signs of premature aging. Skin looks firmer and plumper, as youthful skin bounce and even-tone are restored.Note how it says skin “looks” firmer, not is firmer. Vitamin C can do all this, but this serum uses a derivative that delivers resists slowly.
CEO 15% Vitamin C Brightening Serum, uses a sophisticated, ultra-powerful form of Vitamin C called THD Ascorbate. Both highly stable and oil-soluble, THD Ascorbate rapidly absorbs into the skin for visible anti-aging benefits, including visual improvement in loss of firmness, the appearance of lines and wrinkles, and dark spots and dullness.THD Ascorbate can help with all this. But, again, results are slow.

Price & Availability

$85.00/£70 at Cult Beauty, Dermstore, Nordstrom, Revolve and Sephora

Do You Need It?

Nope. There are better Vitamin C serums out there.

Dupes & Alternatives


Aqua (Water), Tetrahexyldecyl Ascorbate, Squalane, Peg-8 Beeswax, Hydrogenated Polydecene, Polyglyceryl-6 Distearate, Ppg-12/Smdi Copolymer, Phenoxyethanol, Acetamidoethoxyethanol, Jojoba Esters, Sodium Acrylate/Sodium Acryloyldimethyl Taurate Copolymer, Glycine Soja Sterols, Tocopherol, Glycolic Acid, Caprylyl Glycol, Sodium Phytate, Citrus Aurantium Dulcis (Sweet Orange) Oil, Chlorphenesin, Cera Alba, Glycerin, Isosqualane, C30 Hydrocarbons, Saccharide Isomerate