Paula's Choice C15 Booster review

It’s no secret that Paula’s Choice C15 Booster is my fave Vitamin C serum ever. If you’re a regular here, you’ve heard me rave about this baby for years now, so I thought it was time for it to get a full review.

I know, I know. It’s expensive. Can’t you just get something from The Ordinary? They’ve got like a dozen Vitamin C serums. One must be as good as this, right? Wrong. The Ordinary serums are underperforming and no match for this Vitamin C serum. It’s true you don’t need to spend a fortune to have great skin. It’s also true that cheap skincare must cut corners somewhere – and performance shouldn’t be it.

Paula’s Choice C15 walks that perfect balance between performance, sensory pleasure, and price tag. Here’s what makes this serum stand out from the crowd (and a steal compared to true valid alternatives, like Drunk Elephant C-Firma Day and Skinceuticals CE Ferulic):

About The Brand: Paula’s Choice

Paula’s Choice was founded by skincare guru Paula Begoun. Paula started her career as a makeup artist – and was fired from the counter she was working at for telling her customers the truth about what skincare products could and couldn’t do!

When she decided to start her skincare line, she adopted the same ethos. Take Vitamin C serums, for example. While most brands create Vitamin C serum with barely a drop of this antioxidant in it, Paula turned to science and learned all the ingredients for the perfect Vitamin C serum: 15% L-Ascorbic Acid, 1% Vitamin E, and 0.5% Ferulic acid, in an opaque container. And, unlike other competitors, didn’t charge you a kidney for it.

As long as Paula was at the helm, you could count on this brand to take a scientific approach to skincare. Since she sold it, the new formulations are becoming a bit too gimmicky. But this old gem still stands the test of time. Phew!

Key Ingredients In Paula’s Choice C15 Booster: What Makes It Work?


Ascorbic Acid is the pure and most-effective form of Vitamin C. Here’s how it keeps your skin young:

  • It fights the free radicals: Free radicals are the little molecules that destroy collagen and elastin, leading to premature wrinkles. By destroying them, Vitamin C prevents premature aging.
  • It brightens the complexion: It gives skin a lovely glow and even helps fade away dark spots.
  • It boosts collagen: Collagen is the protein that keeps skin firm. The more collagen your skin has, the longer you keep it from sagging.
  • It enhances sun protection: Vitamin C is NOT a sunscreen and should not be used as such. But, even the best sunscreens let between 1-5% of UV rays through. The UV rays that make it through can generate free radicals. Vitamin C tackles them, preventing sun damage.

The catch? L-Ascorbic Acid must be formulated at a pH below 3.5 to work its magic. But low pHs can be irritating for sensitive skin. If yours can’t tolerate Vitamin C serums, this is why. Paula’s Choice C15 Booster has a pH of 3, so it’s effective and not terribly harsh (but it may still cause tingling in very sensitive skin).

One more thing: L-Ascorbic Acid goes bad within weeks. You can’t order this serums now, leave it in a drawer for 6 months, and expect it to still work when you finally decide to use it. If you buy it now, use it now.

Related: What’s The Best Form Of Vitamin C?

Paula's Choice C15 Booster 02


Vitamin C is a powerful antioxidants alone. But pair it with its BFFs ferulic acid and vitamin E and it becomes unstoppable.

A study conducted by Duke University has found that “its [ferulic acid] incorporation into a topical solution of 15% l-ascorbic acid (Vitamin C) and 1%alpha-tocopherol (Vitamin E) improved chemical stability of the vitamins (C+E) and doubled photoprotection to solar-simulated irradiation of skin from 4-fold to approximately 8-fold as measured by both erythema and sunburn cell formation. This combination of pure natural low molecular weight antioxidants provides meaningful synergistic protection against oxidative stress in skin and should be useful for protection against photoaging and skin cancer.”

In plain English, when used together, ferulic acid, Vitamin C and Vitamin E double their own sun protection properties and help you fight premature wrinkles much faster. Paula’s Choice C15 Booster uses the perfect combination: 15% L-Ascorbic Acid, 1% Vitamin E and 0.5% Ferulic Acid.

Related: Why Your Vitamin C Serum Should Always Contain Ferulic Acid


Sodium Hyaluronate is a form of Hyaluronic Acid. Hyaluronic Acid is a moisture magnet: it attracts moisture from the environment into the skin, helping to keep it hydrated for longer. It’s so powerful, it can hold up to 1000 times its weight in water! All that moisture makes skin plumper, softer and brighter. (Moisture is the secret behind Korean skincare, remember?)

Related: The Complete Guide To Hyaluronic Acid In Skincare

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):

The Rest Of The Formula & Ingredients

NOTE: The colours indicate the effectiveness of an ingredient. It is ILLEGAL to put toxic and harmful ingredients in skincare products.

  • Green: It’s effective, proven to work, and helps the product do the best possible job for your skin.
  • Yellow: There’s not much proof it works (at least, yet).
  • Red: What is this doing here?!
  • Water: The base, and main solvent, of this product.
  • Butylene Glycol: It dissolves other ingredients and enhances the texture and feel of the formula.
  • Ethoxydiglycol: It’s a solvent that helps dissolve other active ingredients in the formula. It also improves the texture, so it’s more pleasant to use.
  • Glycerin: It’s a humectant that attracts water from the environment into your skin and binds it there. Your skin uses the extra hydration to become softer, smoother, and take on a dewy glow.
  • PPG-26-Buteth-26: It helps the oily and watery parts of a formula blend together beautifully and makes skin softer.
  • PEG-40 Hydrogenated Castor Oil: It keeps the oily and watery parts of a formula from separating (oil and water don’t mix on their own, remember?).
  • Pentylene Glycol: It’s an emollient that makes skin softer and smoother.
  • Hexanoyl Dipeptide-3 Norleucine Acetate: According to the manufacturer, it can speed up the skin’s natural exfoliating process to make your complexion brighter and smoother hydrate skin; and reduce wrinkle depth. I’m sure it does some of it, but I need more independent proof before I endorse it, ya know?
  • Lecithin (skin-restoring/hydration):
  • Panthenol: A.k.a. vitamin B5, it’s a humectant that increases hydration into the skin and prevents water loss. While it’s at it, it also soothes irritations.
  • Bisabolol: The active ingredient that gives chamomile its soothing properties. It calms down irritations and reduces redness.
  • Oryza Sativa (Rice) Bran Extract (skin-softening/chelating agent):
  • Propyl Gallate: A synthetic antioxidant that fights free radicals and makes the other antioxidants here more stable and effective.
  • Sodium Gluconate: It attaches to the metal ions in the water that would spoil the formula and neutralises them. This way, it extends the shelf life of the serum.
  • Sodium Hydroxide: It adjusts the pH of the serum, so that Vitamin C can work its best.
  • Phenoxyethanol: It’s a preservative that kills bacteria, extending the shelf life of your serum.
  • Ethylhexylglycerin: Although it has some hydrating properties, it’s used here as a preservative to kill any bacteria that may make the serum go bad faster.


I adore the texture of this serum. It’s lightweight to the point of runny, which can annoy some people. Me, I appreciate how fast it absorbs onto my skin. Plus, it’s not greasy and leaves no residue behind. It’s just a pleasure to use.


Like all Paula’s Choice products, it’s fragrance-free. I’m totally on board with this choice. While a part of me appreciates a serum that smells like a garden in full bloom, I know that fragrance is one of the most irritating ingredients in skincare. A high concentration of Vitamin C already has the potential to be irritating for sensitive skin – but at least you’re getting its anti-aging benefits. Fragrance is just irritating with no extra benefits for your skin. Why use it?

How To Use It

I always recommend you use your Vitamin C serum (and this is no exception) in the morning, after cleansing, to supercharge the sun protection from your sunscreen. You can either use it alone or mix it with your moisturiser (this dilutes it a little). You’ll see results faster if you use it alone.


The serum comes in a white bottle with orange accents that reminds you of Vitamin C. It’s sleek and looks good on your vanity. But does it keep the antioxidants inside safe? Vitamin C, Ferulic Acid, and Vitamin E all go bad when exposed to light and air. It doesn’t happen overnight, but you do want a packaging that minimise exposure, so your serum will be effective for longer. This bottle has a screw on cap that you can replace with a dropper applicator when you’re ready to use it. It only dispenses the amount of product you need and minimises exposure to light and air, so your antioxidants last longer.

Performance & Personal Opinion

Paula’s Choice C15 Booster is a clear yellow in colour. That’s cool. Just make sure you use it before it turns brown (the colour of death for Vitamin C). As a rule, the darker the colour, the less effective Vitamin C becomes.

Like all Vitamin C serums (well, those that are properly formulated, anyway…), it brightens a dull complexion, gives skin a lovely glow, and helps fade away dark spots. Of course, don’t expect results overnight (that’s true for any serum). But, with regular use, you’ll see results.

It’s the addition of Vitamin E + Ferulic Acid (at a lower price than most of its competitors) that makes this a must-have for me. This combo helps boost sun protection and prevent wrinkles. But you won’t see it straight away. You have to use it constantly for years to wake up one day and realise you’re aging better than your friends.

One more thing: I have resistant skin, so I can use this without any trouble. But, if your skin is sensitive, you may experience tingling or stinging. If this happens, cut back use to a couple of days a week to build up tolerance or switch to a derivative of Vitamin C.

Related: Can You Use Vitamin C If You Have Sensitive Skin?

Paula's Choice C15 Booster 01

How Does Paula’s Choice C15 Booster Compare To Paula’s Choice C25 Super Booster?

VITAMIN C 15% 25%
TEXTURE Lightweight and runny Smooth, silicone-based
BEST FOR Anti-aging Fading dark spots
SKIN TYPE Dry, combination, normal Resistant skin

Paula’s Choice C25 Super Booster is a simpler formula. For starter, you get 25% of L-Ascorbic Acid instead of 15%. This is both good and bad news. Good because it’s able to fade away dark spots faster. Bad because, at this high concentration, Vitamin C can be irritating. This is only for people with very resistant skin that doesn’t get irritated easily.

Paula’s Choice also removed Vitamin E and Ferulic Acid. This makes the serum a better option for fading dark spots than preventing premature aging. Its texture is silicone-based, so smoother, lightweight without being runny.

Paula’s Choice C15 Booster is still my fave out of the two. Unless you have very severe dark spots, you don’t need 25% Vitamin C. Plus, with C25 Super Booster, you’re missing out on the anti-aging benefits of other antioxidants and have a higher chance of irritation.

That’s the million dollar question, right? There are sooooooo many Vitamin C Serums on the market, which one is worth the splurge? Let’s find out:

VITAMIN C 15% 15% 15% 15% Various % 20%
TEXTURE Lightweight and runny Thicker and sticky Lightweight Lightweight Lightweight lotions and serums Lightweight and runny
IRRITATING POTENTIAL Low Low Low Low Low to high, depending on the formula High
  • Drunk Elephant C-Firma Day ($78.00): It contains the same active combination, 15% L-Ascorbic Acid, 1% Vitamin E, and 0.5% Ferulic Acid. Plus a big dollop of marula oil that makes the texture thicker and sticker. It’s also more hydrating, so if you have dry skin, it’s a good pick for you. Available at Boots, Cult Beauty, and SpaceNK.
  • MaeLove The GlowMaker ($29.95): Same combo of active ingredients, 15% L-Ascorbic Acid, 1% Vitamin E, and 0.5% Ferulic Acid. Plus hyaluronic acid and aloe vera to hydrate skin. It’s a great buy if you’re on a budget and your skin isn’t sensitive. Available at Maelove.
  • Skinceuticals CE Ferulic ($169.00): The original 5% L-Ascorbic Acid, 1% Vitamin E, and 0.5% Ferulic Acid serum. Plus, it’s infused with Hyaluronic Acid to hydrate skin. It’s a simple formula that doesn’t have all the bells and whistles of Paula’s Choice C15, but in terms of performance, it’s still the best on the market. Available at Dermstore and Skinceuticals
  • The Ordinary Vitamin C Serums: I DON’T recommend The Ordinary Serums. None of them contain the combo of Vitamin C + Vitamin E + Ferulic Acid. Plus, most of them use Vitamin C derivates that haven’t been much researched yet. They’re cheaper, but you’re getting a subpar performance too.
  • Timeless Vitamin C + E Ferulic Serum ($17.95): This serum contains 20% Vitamin C + 1% Vitamin E + 0.5% Ferulic Acid. 20% Vitamin C works better at fading away dark spots, but it’s also more irritating. This is a serum only for resistant skin. If you’re looking for your first Vitamin C serum, this isn’t it. Available at Yes Style.

What I Like About Paula’s Choice C15 Booster

  • Lightweight texture
  • Fragrance-free
  • Prevents premature aging
  • Boosts sun protection
  • Brightens the complexion
  • Slightly hydrating
  • Beautiful packaging, keeps the antioxidants inside stable and effective for longer
  • Cost-effective

What I DON’T Like About Paula’s Choice C15 Booster

  • 15% Vitamin C may irritate sensitive skin

Who Should Use This?

  • Anyone who wants to prevent premature aging
  • Anyone who wants to fade away dark spots
  • Anyone who wants to supercharge their sun protection
  • Dry skin
  • Dull skin
  • Mature skin

Instead, I don’t recommend it to acne-prone skin (you’re better off with vitamin C derivative Sodium Ascorbyl Phosphate) or sensitive skin (may be irritating for you).

Does Paula’s Choice C15 Booster Live Up To Its Claims?

This concentrated booster with 15% pure vitamin C dramatically brightens uneven skin while improving the appearance of wrinkles and fine lines. True.
Feather-light, liquid formula absorbs quickly. True.
Diminishes visible signs of aging for smoother, brighter, and firmer-feeling skin with a blend of 15% stabilized vitamin C (l-ascorbic acid) at a pH of 3.0, potent antioxidants including vitamin E and ferulic acid, and skin-smoothing peptides. You’ll see dramatically younger-looking and more radiant skin day after day! Mostly true. I wouldn’t say the results are dramatic, but this serum does work.

Is Paula’s Choice C15 Booster Cruelty-Free?

Yes, this serum is cruelty-free. The brand doesn’t test on animals and doesn’t sell products in countries where animal testing is required by law.

Price & Availability

$55.00/£46.00 at Cult Beauty, Dermstore, Sephora, Paula’s Choice, and SpaceNK

The Verdict: Should You Buy It?

Yes! If you’re looking for an effective Vitamin C serum (and your skin isn’t sensitive or acne-prone), this is one of the best on the market. It works and doesn’t break the bank.

Dupes & Alternatives

  • Drunk Elephant C-Firma Day ($80.00): It’s more hydrating, has a sticky texture, and is better suited for dry skin. Available at Boots, Cult Beauty, and SpaceNK.
  • MaeLove Glow Booster ($27.95): The cheapest Vitamin C serum in this list, it does everything the others do, but it contains a citrus extract that may be irritating for sensitive skin. Available at Maelove.
  • Skinceuticals CE Ferulic ($169.00): The original Vitamin C serum, it costs an arm and a leg, but it works wonders and delivers what it promises. Available at Dermstore and Skinceuticals.


Water (Aqua), Ascorbic Acid (vitamin C/antioxidant), Butylene Glycol (solvent/texture enhancer), Ethoxydiglycol (solvent/texture enhancer), Glycerin (skin-replenishing), PPG-26-Buteth-26 (emulsifier/skin-softening), PEG-40 Hydrogenated Castor Oil (emulsifier/solubility enhancer), Pentylene Glycol (skin-softening slip agent), Tocopherol (vitamin E/stabilizing antioxidant), Sodium Hyaluronate (hydration), Hexanoyl Dipeptide-3 Norleucine Acetate (skin-restoring peptide), Lecithin (skin-restoring/hydration), Ferulic Acid (stabilizing antioxidant), Panthenol (vitamin B5/skin-softening, skin-soothing), Bisabolol (skin-soothing), Oryza Sativa (Rice) Bran Extract (skin-softening/chelating agent), Propyl Gallate (antioxidant), Sodium Gluconate (chelating agent), Sodium Hydroxide (pH adjuster), Phenoxyethanol (preservative), Ethylhexylglycerin (preservative).