Paula’s Choice RESIST C15 Super Booster Review

In Paula's Choice, Skin Care Products by Angie Canning8 Comments

RESIST C15 Super Booster

The RESIST C15 Super Booster is a new targeted skincare product from Paula’s Choice released within the past few months.  I have been testing out this product for the past couple of months and today I’m ready to share my thoughts with you!


The RESIST C15 is dispensed with a dropper.  The glass packaging and opening have been specifically designed to minimize light and air exposure. 

From Paula’s Choice:

RESIST C15 Super Booster is a concentrated, light-as-water liquid treatment product designed to supercharge your Paula’s Choice serum, or it may be used alone. A blend of 15% stabilized vitamin C (l-ascorbic acid) at a pH of 3.0, antioxidant vitamin E, ferulic acid, and peptides repairs visible signs of aging and stimulates collagen production for smoother, brighter, and firmer skin.

Vitamin C also helps protect skin from environmental damage as it evens your skin tone. You’ll see dramatically younger, healthier, and more radiant skin in weeks!

The RESIST C15 Super Booster has been designed for all skin types and is:

    • Effective for: Anti-Aging, Brown Spots, Wrinkles
    • Designed to supercharge any Paula’s Choice serum or moisturizer
    • Quickly brightens skin and reduces brown spots
    • 15% stabilized vitamin C plus potent anti-aging ingredients promote firmer skin
    • Improves the appearance of wrinkles and uneven skin tone
    • Helps fade red or brown marks from past breakouts
    • Water-light texture is suitable for breakout-prone skin
    • Specially packaged to minimize light and air exposure
    • Clinically proven non-irritating
    • 100% fragrance free, no added dyes
    • No animal testing

Over the past two months I have used C15 as part of my nighttime routine, applying 3-4 drops to my skin after cleansing, toning and using my exfoliant.  The C15 has been designed to mix with other Paula’s Choice serums and products without reducing effectiveness of the products so you can mix and match according to your needs.  I have experimented with the application of C15; first by applying the C15 Super Booster directly to the skin followed by my moisturizer on top as well as mixing the C15 with my favorite serum (shown below).  I love mixing it with my serum because then I can skip the moisturizer step before bed, but I find either way works well for me.  You can experiment with which products work best for you, but Paula’s Choice gives some great ideas on their site by offering “packages” of C15 Super Booster together with one of their other targeted products.  It is important to note you should not mix this product with your SPF because it will dilute the SPF.

I continue to use my regular Paula’s Choice skincare products (cleanser, toner, BHA and AHA exfoliants, serum and SPF) while using this product, and within the past three months I have also added using a Tretinoin cream every other day, and I am loving the entire routine!  (I will update my full skincare routine soon!)


Currently my favorite combo: the RESIST C15 with RESIST Ultra-Light Super Antioxidant Concentrate Serum.

Scent and Shelf-Life – The C15 Super Booster is nearly clear, with a very slight tint of “orange”.  The scent reminds me kind of like a “vitamin” but I do not find it unpleasant.  After application I can smell it for several minutes before it fades away.

C15 has a shelf-life of 3 months, after which it may begin to lose its effectiveness.  I asked Paula’s Choice about this:

“The C15 is recommended to be completed by the end of 90 days.  The reason for this is that even with the packaging upgrades (internal air restrictor and tinted glass), high percentage ascorbic acid serums are difficult to keep potent due to their notorious instability.  Within 90 days, the C15 will remain its full potency, but after that time we can’t say with certainty that it would remain as potent.  The sure sign of a vitamin C treatment like this losing strength is a color change—shifting to a dark brown/orange is the oxidization of the ascorbic acid.  We know in extensive testing the C15 remains stable up until 90 days, but after than there is a gradual shift which can vary by external, environmental factors.”

With using 3-4 drops of this product once per day, I have used approximately 1/4 of the product over a two month period.  I have since increased use to twice per day, which would use up the product more quickly, making it closer to using it within the recommended 3 month period for me.  That being said, I will personally use the product past three month mark however, but I will immediately discontinue use if the product begins to change color (darken) or begins to develop an odor.

If you find you are only using the product once or twice per week, you might consider ordering the sample size also offered from Paula’s Choice.

Paula’s Choice “Power Couples”!

While at first I was uncertain if I wanted to add another product to my twice-daily skincare regimen, I have found the RESIST C15 Super Booster a very easy fit.  I love the anti-aging and skin-lightening benefits that using a Vitamin C product offers in my skincare regimen, and I can’t see my routine without it!

Visit for FAQ’s and research on this product.

$45 US, 20 ml / 0.67 oz. or $9 US, trial size (0.12 oz).  Available at  Also available as part of a set with another targeted skincare product (shown above).


Key Ingredients: ferulic acid, acetyl octapeptide-3, glycerin, panthenol, tocopherol, sodium hyaluronate, ascorbic acid

Product Ingredients:  Water, Ascorbic Acid (vitamin C/antioxidant), Ethoxydiglycol (slip agent/penetration enhancer), PPG-26 Buteth-26 (emulsifier), PEG-40 Hydrogenated Castor Oil (thickener), Tocopherol (vitamin E/antioxidant), Ferulic Acid (antioxidant), Sodium Hyaluronate (skin-repairing ingredient), Acetyl Octapeptide-3 (cell-communicating ingredient), Glycerin (skin-repairing ingredient), Panthenol (skin conditioning agent), Sodium Metabisulfite (stabilizer/antioxidant), Triethanolamine (pH adjuster), Phenoxyethanol (preservative).

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  1. I love C15 too! Glad you reported the orange tint, as I initially thought it was a sign of oxidation.

    1. Author

      I’m glad to hear that as well — here I was worried at first too, lol! 😉 How fast are you using yours up? Do you think it will be hard to use up within 3 months? Just curious! 🙂

  2. I really enjoyed your review! When I started using this serum for the first month, I wasn’t sure if I noticed much improvement using just a couple drops mixed with the ultra light antioxidant serum. Then after I read about the 90 day recommended shelf life, I started using more of the product, more as a toner to get the best use of the active ingredients. I just finished my first bottle in about 3 months and I will order my second today. I can definitely say that this significantly improves the overall texture and smoothness of the skin, especially when used as a toner. When used at night, my makeup the next day definitely applies better and more evenly.

  3. I use this stuff like its a toner, i.e. a lot! I mix it with the AHA 10%, with my serum, with the moisterizer, and with the Resist Intensive Retinol serum. After about a week my skin felt like glass, according to a good friend and my mother! I sometimes mix it, sometimes layer it, and sometimes I use it as a last step at night. Trust me, I go through a bottle waaaay before the three month limit.
    The only odd thing I’ve experienced is a slight staining on the last three fingers and nails of my right hand (the one I use to apply it). They looked like I smoked 5 packs of cigs a day, and I’ve never smoked. The CS folks said it can stain if you don’t wash your hands (and if you use it like crack like I apparently do). I have found the one thing that does get rid of the stains: the BHA liquid or the AHA liquid. I use both, so it may be just one of them is doing the trick, but I wanted to get rid of the stains so fast that I haven’t had time to try either one by itself.
    Oh, and one other really odd thing: the finger nails on my right hand are growing twice as fast as those on my left. I thought I was imagining things so I took some snaps via my iCam, and then compared those to new snaps taked 5 days later. No lie, the right hand really needed trimming something awful, while the left could go another day or 3.
    For some reason I take this odd event as encouragement that the product really is effective. Go figure!

    1. Author

      In following up to your last comment – Yes this stuff is almost like a “drug”, and I am definitely addicted! 😉 I love to mix it up as well – thank you for sharing how you mix it up! After using it for a month with the suggested “few” drops I have since been using more of it and I now find no problems with using it up within the 3 month period either. I just ordered another bottle of it and plan to be just as generous in application with what I’m calling “liquid gold” now, lol! 😉 Thank you for sharing your experience with the staining on your hands – I have actually not experienced that, but it is good to know! Lately I have always been mixing it with something else (BHA9, RESIST Retinol, RESIST Skin Balancing Ultra-Sheer, etc.) and then the last bit I actually rub on the top of my hands right before bed so my hands get a little treatment as well – which brings me around to your other comment about the fingernails and YES I totally agree! My nails have never been more healthy looking and they grow like crazy as well, so I think we’re onto something here! 🙂 Since I do not experience the staining I will keep up with the application on the tops of my hands because I’ve also noticed an improvement in the skin there as well. 🙂 All in all, this is a product I will keep up with that’s for sure – happy you like it too! 🙂

    2. Scott, I use topical L-asorbic vitamin c and have had good results. However, all my fingernails are discolored! I thought it was happening internally from the vitamin c because the product does not come in actual contact with my nails, therefore concluding that nothing would be able to remove the stains. I am curious about the products you mentioned to remove the stain.

  4. Glad to hear about the hand discoloration with C15 boost. I thought I had liver disease lol ! Have only noticed it since I started using the C 15 Boost so that brought me here. Love Paula’s Choice products. Have used them for a long time. My sister works for a Plastic Surgeon and recommended them to me many years ago. Affordable and works great!!

    1. Author

      So glad it helped you out! It is so strange that it does that – but now each night I just make sure to rub it in all over the tops of my hands so it doesn’t settle and all has been good now! I’m still using PC exclusively and definitely can’t quit it – it’s so good! 😀 Happy to hear you love it too. 🙂

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