How to find the best Vitamin C Serum for you Pt 1

We talked about what an awesome and multi-functional ingredient vitamin C, L-ascorbic acid (L-AA), is. It’s no surprise that many brands have their own take on vitamin C making the L-AA landscape quite vast. But not to fear! L-ascorbic acid products can actually be broken down into three types. So today, let’s walk through the different product types and learn how to incorporate them in your routine.

You can check out products mentioned in this article here.

Classic Water Based Serum

water based vitamin c ascorbic acid serum

Water-based L-AA serum in combination with vitamin E and ferulic acid was the classic, patented formula developed by Skinceuticals. This combination stabilized degradation-happy L-AA long enough for skin to take advantage of its brightening, antioxidant properties. This is still our go-to recommended format for its ease of use. The downside is that the formulas can be a bit sticky and smells… funky. Hot dog water anyone?

  • How to use it in your routine: First step post cleansing in the mornings. Can be used both morning and night.
  • Most degradation happy of the bunch: Store in vampire settings - cool, dark, and sealed!
  • What to look for: When it starts turning amber or dark brown, it’s time to go.
  • Best for Beginners or those with sensitive skin: Klairs. L-AA is effective even at a low 5%, but there are very few options out there at this level. If you’re worried about potential irritation, Klairs Freshly Squeezed Vitamin C Drops is one of the few products on the market at this concentration.
  • Best dupe for budget shopping: Timeless Skincare. Though Skinceutical’s CE Ferulic is the OG, proven formula that has been validated by countless clinicals, $166 may be a bit steep. Thanks for more budget-friendly dupes, you can make sure this combination is right for your skin before splurging. 

Powder Formula

powder vitamin c l ascorbic acid products

Another way to get around L-AA’s infamous instability is to simply avoid water. Powder formulas are one of the most stable forms you’ll find on the market. The downside is the messiness and you’re never quite sure if you’re using the right amount. Also we’ve lost a few of those spoons...

  • How to use it in your routine: The key to powder vitamin C formula is that you need to dissolve it before applying for the L-AA to work. L-AA is very water soluble, so the best way to use this is to just mix a small scoop in your favorite hydrating serum or gel. Do not mix with face oils or thicker creams — odds are it wouldn’t dissolve right.
  • Best for Beginners: Pure vitamin C like TO or Philosophy is very acidic and can be irritating to vitamin C beginners or those with sensitive skin. We would recommend starting with Neogen. 


vitamin c suspension products

The last more common format of L-ascorbic acid are suspensions. These prevent vitamin C from degrading by suspending particles in an anhydrous (waterless) formula. The key to finding a good suspension formula is avoid grittiness at all cost. Because the vitamin C isn’t truly dissolved, it needs to be ultra fine for it to work better.

  • How to use in your routine: this is a bit tricky! Many of these products have a fairly high oil load (Beautystat's formula even contains occlusive gold standard petrolatum!), it should be your last “treatment” step before moisturizer and sunscreen. If you use any other toners, serums, they should go before this type of vitamin C formula.
  • Chemists’ Comment: Personally not our favorite format. Not all suspensions are made alike, but these can also serve as a dual purpose moisturizer.

TLDR Takeaway

  • You can find ascorbic acid in 3 different product formats: water-based serums, powder, and anhydrous suspensions.
  • Water-based serums are the classic way to go, just be sure to store in vampire settings and be mindful of the shelf life.
  • You worry less with powder vitamin C, the downside is dosage and the mess left on your sink raises a few eyebrows.
  • Suspensions are typically anhydrous, silicone-based formulas. Not all are created equal - look for a uniform formula with no grit.


Hello, some instructions for use say different things. In one Vit C is allowed and in others Vit C is not allowed 😏 Is this marketing or are there cosmetic products (non-professionell) that are not allowed to be combined?
Greetings from Germany 🇩🇪

Susanne June 29, 2023


SONIA August 17, 2021

LAA 15% (DE) + hyloronic acid(ordinary) is making my skin oily , does that mean LAA is not suitable for my skin? Should i look for derivatives
Thanks for the taking my question

Heenal July 06, 2021

Interested in your opinion on The Ordinary’s Ascorbic Acid 8% + Alpha Arbutin 2%! It’s anhydrous and non-gritty since it’s suspended in propanediol, but I wonder about its stability and efficacy?

Ris March 11, 2021

What if vitamin c serums irritate your skin/cause reactions when use. What are some good alternative antioxidants?

Megan January 19, 2021

What about the the MAP cream from the ordinary and vit c from Avenue ? Where does that fit in and is it recommended for beginners/sensitive skin ?

B December 10, 2020

Thanks for this post!! I just got the beautystat one and it seems pretty gritty – is it too gritty to work well? Thanks!

Ellie December 10, 2020

Leave a comment

All comments are moderated before being published