Vitamin C serum review: Paula’s Choice, Ultraceuticals, Ausceuticals

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How to cite: Wong M. Vitamin C serum review: Paula’s Choice, Ultraceuticals, Ausceuticals. Lab Muffin Beauty Science. November 8, 2016. Accessed May 22, 2024.

I’ve been trying out a lot of vitamin C serums lately as long summer days and increased UV exposure looms closer. In case you’ve forgotten from my reviews of the Obagi, Indeed and Ole Henriksen serums, vitamin C is an amazing skincare multitasker. It can soak up incoming sun damage, fade existing sun damage and hyperpigmentation (such as acne scars) for a glowing complexion, and promote collagen synthesis to combat fine lines and wrinkles.

Today I’m reviewing some water-based vitamin C serums from Paula’s Choice, Ausceuticals and Ultraceuticals. The advantage of water-based vitamin C serums is that they can contain ascorbic acid, the best studied and (as far as we know) most effective version of vitamin C. Other vitamin C derivatives need to be broken down until ascorbic acid by the body before having its full antioxidant, collagen-boosting potential. (Some oil-based serums can also contain ascorbic acid in undissolved form, but its effectiveness is less certain.) On the other hand, water-based vitamin C products are less stable, so the active ingredient won’t be around as much! I’ll be reviewing some oil-based vitamin C products next.

Paula’s Choice RESIST C15 Super Booster

Paula’s Choice RESIST C15 Super Booster contains 15% vitamin C in the form of ascorbic acid, along with vitamin E (tocopherol) and ferulic acid. This antioxidant triple combo is commonly known as C+E+Ferulic. Antioxidant ingredients can work synergistically to replenish each other, which means greater overall antioxidant ability (read: anti-aging action). This means it works better on the skin – vitamins C and E together are twice as effective at UV protection as either vitamin alone, while C+E+Ferulic was found to be twice as good as vitamins C + E together or ferulic acid alone.

It also oxidises slower in the bottle, so the shelf life is much better. A water-based ascorbic acid serum by itself has a shelf life of a few weeks before it’s too oxidised to be beneficial, which you can see as the serum turns yellow in colour. In contrast, the C+E+Ferulic combo has a shelf life of a few months (longer if you keep it in the dark, without air exposure and in a cold place).

RESIST C15 Super Booster ($62 AUD or $49 USD for 20 mL) is formulated at a pH of around 3 for efficient penetration of ascorbic acid, which is well known for being a difficult ingredient to get to absorb into the skin. It comes in an opaque orange dropper bottle, which unfortunately allows for a lot of air exposure.

The biggest disadvantage to this product though, in my opinion, is the smell, which can best be described as “hot dog water”. I’m sure a lot of people will be able to handle it, which mostly goes away once you put moisturiser on it, but I found it difficult to convince myself to use it regularly. It’s my main gripe with fragrance-free products – if a pleasant fragrance makes me want to repeatedly use the product, then it’ll be more effective than a fragrance-free product. I’ve passed this onto my sister who can barely smell it, so it’s not a dealbreaker for everyone.

Water, Ascorbic Acid, Ethoxydiglycol, PPG-26 Buteth-26, PEG-40 Hydrogenated Castor Oil, Tocopherol, Ferulic Acid, Sodium Hyaluronate, Acetyl Octapeptide-3, Glycerin, Panthenol, Sodium Metabisulfite, Triethanolamine, Phenoxyethanol.

Vitamin C serum review: Paula's Choice, Ultraceuticals, Ausceuticals

Ausceuticals 20% C+ Serum

Ausceuticals is a small skincare company based in Perth, Australia that I’ve recently discovered. Their products are quite science-based, and are formulated with the aim of keeping them as inexpensive as possible.

The 20%C+ Serum contains the C + E + ferulic acid combo, as well as a laundry list of other antioxidants too: phloretin, astaxanthin, lycopene, lutein, alpha lipoic acid, beta carotene, fucoxanthin, cranberry juice and pomegranate seed oil. The rest of the ingredients are mostly humectants (sea kelp bioferment, glycerin, sodium PCA, hydrolyzed collagen, hyaluronic acid). It has a light citrussy scent and comes in an opaque pump bottle (though unfortunately not airless). The pH is 2.7, which is in the correct range for ascorbic acid to be effective. The best thing about this serum is that it’s only $39 AUD for 30 mL, which is very budget-friendly for a product with so many effective ingredients! This is my pick of the three serums here.

Water, Sea Kelp (Lactobacillus/kelp ferment filtrate) Bioferment, Glycerin, Ascorbic Acid (L), Sodium PCA, Cranberry (Vaccinium macrocarpon) Juice, Ferulic Acid, Phloretin, Hydrolyzed Collagen, Hyaluronic Acid, Porphyridium Extract, Fucoxanthin, Cranberry (Vaccinium macrocarpon) Extract, Pomegranate Seed (Punica granatum) Oil, Tocotrienols, Vitamin E Oil (Alpha-D Tocopherol), Astaxanthin, Lycopene, Lutein, Alpha Lipoic Acid, Beta Carotene, Fragrance, Phenoxyethanol (and) Caprylyl Glycol (and) Sorbic Acid

Ultraceuticals Ultra C10+ Firming Serum

Ultraceuticals Ultra C10+ Firming Serum contains 10% ascorbic acid with a bunch of anti-aging peptides (palmitoyl hexapeptide-12 (pal-KTTKS), palmitoyl tetrapeptide-7, palmitoyl tripeptide-1, oligopeptide-1). The scent is mostly alcohol, with a very slight metallic tinge. It’s quite pricey ($110 AUD for 30 mL), and while Ultraceuticals seems to have worked out a way of stabilising the vitamin C, it’s hard to tell how oxidised the product is since it comes yellow. If you’re looking for a vitamin C serum in combination with anti-aging peptides, I’d recommend paying a little bit extra ($138 AUD for 30 mL) for the 23% version (C23+ Firming Concentrate), which is water-free according to the ingredients list, so it’s easier to tell if it’s gone off.

Aqua, Alcohol Denatured, Ascorbic Acid, Ethoxydiglycol, Glyceryl Polymethacrylate, Glycerin, Propanediol, PEG-8, Palmitoyl Hexapeptide-12, Palmitoyl Tetrapeptide-7, Palmitoyl Tripeptide-1, Caproic acid, Oligopeptide-1, Sodium PCA, Polysorbate 20, Dextran, Hydroxyethylcellulose, Carbomer, Anogeissus leiocarpus Bark Extract, Menyanthes Trifoliata Leaf Extract, Butylene Glycol, Caprylyl Glycol, Caprylhydroxamic Acid, Disodium EDTA, Lactic Acid, Sodium Hydroxide.

These products were provided for editorial consideration, which did not affect my opinion. This post also contains affiliate links – if you decide to click through and support Lab Muffin financially (at no extra cost to you), thank you! For more information, see Disclosure Policy.

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37 thoughts on “Vitamin C serum review: Paula’s Choice, Ultraceuticals, Ausceuticals”

    • Yes, hot dog water! I was thinking ham, but that’s more accurate. I can’t stand to wear it during the day when it would be most effective, because I can smell it all day long.

      • I haven’t tried it during the day, but my sister reckons that putting Biore Watery Essence got rid of the smell for her. She does have a pretty poor sense of smell though!

  1. I do love the Paula’s Choice C15 Booster, but yes, that meat smell! Ugh. I normally mix it with a hydrating serum that smells nicer to mask the smell. It does make my skin look really smooth and radiant though.
    I’m toying with paying the big bucks for the Skinceuticals C E Ferulic… have you tried that?

    • I haven’t – the price tag is a bit too much for me unfortunately, though I’ve heard good things about how it works…but apparently it also smells like hot dogs!

  2. Hi Michelle
    Thanks for your post! Fantastic to have a scientist reviewing these products.
    I am concerned about the oxidisation of Vit C.
    With Ausceuticals, have you reviewed how quickly it oxidises?
    And how does it compare with Ultraceuticals Vit C cream (not serum)?
    Just to quote from Ultraceuticals website re its Vit C creams:
    “The vitamin C delivery system in Ultraceuticals creams involves the combination of extremely fine particle size (micropulverised) vitamin C in an anhydrous system incorporating a carrier to assist in transdermal absorption. The combination of these three elements results in a much more stable and certain delivery of vitamin C into the skin.”

    Would really appreciate your thoughts. Thanks Michelle.


    • Hi Daisy,

      I haven’t had time to see how long it takes for the Ausceuticals product to oxidise, I would guess at least 3 months though based on the concentrations of C/E/ferulic acid. I haven’t tried the Ultraceuticals cream but if it’s anhydrous it should last much longer, possibly years. The problem with anhydrous vitamin C though is penetration – even though it’s “micropulverised” it still has to dissolve in water (e.g. tiny amounts on the skin) to penetrate, and it probably doesn’t penetrate as evenly. It might be better on slightly damp skin! I’ve tried the Indeed Labs C24 which is a similar concept.

    • I’ve had fantastic luck with vitamin C fading acne scars! I really see the difference when I forget to use it for a while.

  3. Yes, the PC one had the oddest scent on it. But i found that it had little to no effect on my skin, even though I was using it day and night. I finished the entire bottle and was sorely disappointed. My favorite so far is Garnier Dark Spot Corrector (recently undergone a name change) but I’ve moved onto a retinol and I’m liking it so far!

    • That’s unfortunate, especially when you had to suffer through the scent for no reward! I’ll have to try out the Garnier product.

  4. LMAO. Hotdog water is literally the best way to describe it haha. I know PC has a quarrel with frangrances but my god, sometimes I wonder if they’re shooting themselves in the foot. I had to stop using their BHA as well cause I couldn’t tolerate the a** smell of it (among other things).

    • I can kind of see their point about avoiding fragrance “just in case” but I think it’s overkill and yeah, it just means I’m going to avoid using their product… Weirdly I have no issues with the smell of the BHA! I wouldn’t say I loved it though…

  5. Can you clarify if vit C is more stable in water based or water-free products?
    I haven’t got it entirely from the article.


    • It’s more stable in water-free products, and more stable in acidic (low pH) water-based products than basic (high pH) water-based products.

    • I’ll try! It’s a bit tricky because I think a lot depends on your skin type and your budget. I can say that my favourite out of the water-based ones I’ve tried so far is the Ausceuticals one!

  6. Have you tried The Ordinary’s Vit C products, or do you plan to? I was hoping to get some input on how you think they would work!

    Thank you for your posts!

    • I’m planning to – it’s only just launched in Australia! I have a bit of a Deciem backlog that I’m trying out at the moment though 🙂

  7. Hi Michelle,
    thank you for the article and for including Ausceuticals’ serum into the review. I’ve never heard of them before, but I will definitely try the product next time – it sounds really good!
    I use Paula’s Choice Resist C15 and I don’t even mind the smell of it, but I don’t like how it makes my skin so sticky after application. Of course Ausceuticals’ serum might turn out the same, but I think it’s worth trying, especially given its awesome price:)

  8. Ah, interesting about the meat-y water fragrance from PC’s Super Booster. Out of the box, I don’t detect much of a scent, but when I apply it after using benzoyl peroxide my face will emanate a pungent, umami-ish kind of smell, not incredibly offputting but very distinct, for a few hours after.

  9. Hi, how does Ausceuticals penetrate to the lower layers of the skin? This is a common issue with many creams, serums etc, I believe. Many don’t have a proper delivery mechanism to get into the skin so ultimately aren’t very effective.

    • Unfortunately (a) in vivo studies are very expensive and (b) non-drug skincare products aren’t allowed to claim that they penetrate to the deeper layers of the skin and have an effect. So there isn’t data for any of these penetrating to the deeper layers AFAIK.

  10. Thanks for reviewing the Ausceuticals serum! I’ve been hunting for a vitamin c serum that’s accessible in Australia and stumbled across the Ausceuticals one. So I tried to look for reviews on it but you’re literally the only one who’s reviewed the product. Anyway, it gave me some confidence to purchase it, so thanks. 🙂

  11. I just found your blog and I am hooked. Thanks for educating us, we need you. I been looking for cheaper option to replace my ultraceuticals vit c & vit a serums, and now I know the vit c not even good. About to try ausceuticals vit c, and pc vit a.
    Thanks heaps!

  12. I know this post is a year old, but it seems Ausceuticals have totally revamped their Vitamin C line. They now have a 10% and 20% serum, and neither ingredients list matches what you have reviewed. It’s a shame as I’d really love to try their products but I’m certain neither the essential oils in the 10% or the citrus extracts in the 20% would agree with my finicky skin!

  13. I realize it’s been a year since you posted this, but I’d like to ask: aside from the unpleasant smell, did you find the Paula’s Choice serum to be effective? Or did you simply not use it enough to tell?

    I recently purchased it and as I’m in the US (and as they’ve changed their product line) I won’t be ordering from the Australian company. I can’t afford the Skinceuticals version, and my generous sample of Dr. Dennis Gross went bad before I could try it.

    So I’d really like to know if you thought it was effective. Thanks in advance!

  14. Hi Michelle! First and foremost, thank you for your blog. I have been waiting for something like it for so long! There are too many options out there when it comes to skin care (and a lot of marketing ploys) so this has been a holy grail website.

    So, I was wondering if you have tried Philosophy’s turbo booster C powder?
    Or if not, I was wondering about 2 ingredients that are in it: zinc PCA and copper PCA. It seems like zinc PCA is said to be a good skin care ingredient but another website says it is hazardous.
    I like the idea of the powder, because I could just mix it in with any of my water based moisturizers.
    However I’m not above mixing in straight Ascorbic Acid, which I was thinking of trying out (although I feel like there’d be no way to tell how much to use for each single application), and it would be difficult to change the pH.

    Any input of yours would be appreciated. Thank you,

  15. Just wanted to say that I’m using the Skinceuticals C E Ferulic and it does have “a smell”. It’s the only Vit C serum I’ve used, so I can’t compare it to others, but it sounds like it might be similar to Paula’s Choice. I’d been trying to place it. It def smelt like food & I’d been thinking maybe a bbq marinade for meat, but ‘hot dog water’ or ‘hot ham water’ (Arrested Development, anyone?) is actually closer to the mark. I didn’t think too much of it at first. I had read about a smell in the reviews. But now I’m starting to look forward to using it up! I can never afford it again, anyway. It was a desperation-buy. But it’s useful to know that PC also had the ‘hot dog water’ smell before I waste more money.


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