As an antioxidant, vitamin C has obvious benefits for skin health when applied topically, so it’s no wonder many brands now offer a vitamin C-infused product. In fact, a search on Amazon for “vitamin C serum” returns hundreds of results.

For any brand thinking of formulating and marketing a vitamin C product, it’s important to know that not all vitamin C is created equal. Given there are so many formulary options available today, why are we still using L-Ascorbic Acid, knowing it is the most difficult one to work with? This post will help you understand more about your vitamin C options.

L-Ascorbic Acid (water soluble)

 Pros: L-Ascorbic Acid is the synthetic active form of vitamin C and mainly used in skin care for brightening skin tone. Much of the benefit delivered by vitamin C is due to its ability to inhibit and reverse hyperpigmentation in skin types across the Fitzpatrick scale. Vitamin C has shown great success with users who suffer from melasma, hyperpigmentation and sun damage. A common misconception is that vitamin C is used as a whitening agent on skin. In reality, vitamin C is a hero when it comes to evening and brightening the skin, rather than bleaching.

Cons: While L-Ascorbic Acid is a powerhouse ingredient that should be in every serum, it also has great limitations which have turned many chemists’ hairs grey. L-Ascorbic Acid is extremely unstable, does not interact well with other ingredients and is extremely sensitive to light and oxygen.

That may sound like the cons outweigh the pros, but there are ways to maximize the benefits of L-Ascorbic Acid while mitigating its shortcomings. The keys to successfully formulating and offering a product containing L-Ascorbic Acid include:

·      Work with an experienced chemist. If your chemist is knowledgeable about pH dependence, oxidation, and skin irritation factors, you can minimize the volatility and produce something your consumers will trust.

·      Plan extra time for R&D. Because L-Ascorbic Acid is extremely unstable, you’ll want to invest more time than usual for stability testing.

·      Quick turns in retail. You don’t want a product containing L-Ascorbic Acid to be a slow seller, because you’re then faced with the possibility of consumers having a bad experience with a product gone bad.

·      Added expenses due to glass packaging. To maintain product stability, you’ll have to use glass packaging. That will also impact shipping costs. 

People often assume that vitamin C (L-Ascrobic Acid) is derived from oranges, so it must be naturally orange in appearance, but that’s not the case. Vitamin C, when dissolved in water, is transparent. Over time, as vitamin C is exposed to oxygen (in other words, as it is oxidized) and sunlight, it begins to turn yellow, then orange, and eventually brown. A serum that is clear, yellow, or orange is still safe for use, but at the brown stage it should be replaced.

An unopened bottle is safe to use for up to two years, but once it is opened the clock starts ticking. We generally recommend consumers use up a vitamin C serum within three months of opening. Keeping serum in a dark and cool place will extend its shelf life. 

If you decide L-Ascorbic Acid is not your ideal vitamin C option, you have alternatives:

·      Ethyl Ascorbic Acid

·      Ascorbyl Palmitate

·      Magnesium Ascorbyl Palmitate

·      Sodium Ascorbate

These derivatives of vitamin C were created to combat some of the issues that drive chemists crazy—pH restrictions, oxidation and instability associated with L-Ascorbic Acid. However, the tradeoff is that by avoiding those issues your product has reduced efficacy. While many of these derivatives are backed by claims about solubility and ability to metabolize in the skin, our experience shows that L-Ascorbic Acid is the most bioavailable and impactful on the skin, which usually makes it worth the extra effort.

Yvonne von Berg

Co-Founder