I advocate FOR the daily use of a topical Vitamin C serum (See this blog)
When you are using L-Ascorbic Acid, which is the pure and active form of Vitamin C, you need to remember that its viciously unstable. All of these states – heat, water, high pH, literally air – cause L-Ascorbic Acid to rapidly degrade to nothing useful. (See this blog)
Therefore, any Vitamin C serum must be a stable formulation to make the cut.
Is the formulation stable?
You’d be surprised how few products have a stable L-Ascorbic Acid formulation. After scouring the ingredient labels of over 200 Vitamin C product – I may not have a life – I have found 3 products that I am confident are stable.
What gives me confidence?
All these products have a variant of the Duke Antioxidant patent (see below), which has the supporting clinical data showing a stable formulation with measurable improvement in skin-ageing.
The gist of the patent (and the formula we are looking for) is:
15% Vitamin C as L-Ascorbic Acid + 0.5% Ferulic Acid + 1% Vitamin E
Therefore, recommendations are based on how close they match this formula AND price.
A quick note on usage….
I have read endless reviews when after a fortnight or even a month, reviewers complain of the lack of visible results. The original patent was based on 16 weeks. You have to use Vitamin C for a long time before you see results….
No 1: Drunk Elephant C Firma Day Serum (US$ 80 for 30ml)
This is as close to the Duke Antioxidant patent as possible and coupled with its LOWER price point, it holds the top spot.
This product has 15% pure L-Ascorbic Acid, 0.5% Ferulic Acid and 1% Vitamin E.
Also, this is the no 1 bestselling Vitamin C serum on Sephora’s USA website.
No 2: Paula’s Choice C15 (US$ 59 for 20ml)
Its close to the original formulation as possible without disclosing all percentages.
This product has 15% Ascorbic Acid and an undisclosed amount of Ferulic Acid and Vitamin E.
With near identical formulations there is a concern about patent infringement – so I get why Paula’s Choice may not wish to disclose this information.
P.S. On a per unit basis, this product is more expensive than Drunk Elephant’s Vitamin C serum.
No 3: Skinceuticals (US$ 166 for 30ml)
Skinceuticals own the Duke Antioxidant patent, so this product is the real McCoy. However, at US$ 166, I will pass on this product, thank you very much.
In case you are one of Elizabeth Warren’s less favoured billionaires, I would encourage you to buy this product.
What were the other products that nearly made the cut?
These were:
The formulation is not identical and this is a dealbreaker.
For example, Peter Thomas Roth Potent C (US$ 98 for 30ml) has 20% THD Ascorbate, 3% Vitamin E and 2% Ferulic Acid. Similarly, the other two products BOTH use THD Ascorbate.
THD Ascorbate IS NOT Ascorbic Acid and the bottom line is stabilized Ascorbic Acid is better than its derivative THD Ascorbate.
Plus, where is the data that this formulation provides better or even identical results to the Duke antioxidant patent?
The Duke antioxidant patent
In 2004, the late Dr Pinnell registered a patent for a stable Vitamin C formula. (Dr Pinnell also founded Skinceuticals).
Just Vitamin C + Vitamin E
- Ordinarily combining Vitamin C with Vitamin E, increases the overall effectiveness of both antioxidants. In fact, a 15% Vitamin C (L-Ascorbic Acid) and I% Vitamin E solution when applied to the skin, can provide 4 times as much photoprotection…
- According to the same research paper, Vitamin C (L-Ascorbic Acid) at 15% saturates the skin and is the concentration at which maximum absorption by the skin takes place. At this level, the Vitamin C remains in the skin for about 4 days.
- Once Vitamin C is absorbed by our skin, the Vitamin C cannot be removed by washing or rubbing.
Vitamin C + Vitamin E + Ferulic Acid
- Ferulic Acid is a very common plant antioxidant.
- The addition of 0.5% Ferulic Acid to a solution of 15% Vitamin C (or L-Ascorbic Acid) and 1% Vitamin E (Alpha Tocopherol Acetate), results in a stabilised solution.
- Ferulic Acid provides stability to 90% of Vitamin C and 100% of Vitamin E.
- In addition, the photoprotection offered by Vitamin C and Vitamin E is doubled from 4 to 8 fold.
That’s it from me. Drop me a line at email@happyskindays.com if you have any queries!
Sources
Fu-Hsiung Lin, Jing-Yi Lin, Ravindra D. Gupta, Joshua A. Tournas, James A. Burch, M. Angelica Selim, Nancy A. Monteiro-Riviere, James M. Grichnik, Jan Zielinski, and Sheldon R. Pinnell, “Ferulic Acid Stabilizes a Solution of Vitamins C and E and Doubles its Photoprotection of Skin” Journal of Investigative Dermatology, November 2005, 125(4):826-32
Lin JY, Selim MA, Shea CR, Grichnik JM, Omar MM, Monteiro-Riviere NA, Pinnell SR: UV photoprotection by combination topical antioxidants vitamin C and vitamin E. J Am Acad Dermatol 48:866–874, 2003
Pinnell SR, Yang HS, Omar M,et al: Topical L-ascorbic acid: Percutaneous absorption studies. Dermatol Surg 27:137–142, 2001