The most crucial element of a Vitamin C facial serum is it's stabilization. To prevent oxidization (turning to an amber color) and ineffectiveness, the serum must be well stabilized. Producing stabilized Vitamin C serum and keeping it stabilized in the bottle is not an easy task. This is one of the reasons why many companies charge well in excess of $160 for a 1 ounce bottle of Vitamin C serum.
Unfortunately, oxidation occurs very easily once the serum is exposed to the elements of air, water, and light.
If you've heard about C-Ester, let's talk about the difference between the L--Ascorbic Acid and C-Ester.
It is very difficult to stabilize Vitamin C, because most skincare companies attempt to stabilize L-Ascorbic Acid (vitamin C), which is naturally unstable. Using stabilized Vitamin C that is not water soluble, such as C-Ester
(Aminopropyl Ascorbyl Phosphate) would solve half the problem. But then you may ask....So why aren't
they simply using C-Ester instead of L-Ascorbic Acid? The answer is the high COST.
While L-Ascorbic Acid costs about $30 per pound, C-Ester costs about $500 per pound. That's a whopping 17X price difference. But it is well worth it, because C-Ester doesn't get easily oxidized and therefore retains its effectiveness.
C-Ester is preferred by many professionals for having superior stability and effectiveness. According to www.truthinaging.com, "It’s particularly lauded for reducing melanin production-the culprit behind age spots, Melasma and hyper-pigmentation. The Aminopropyl Ascorbyl Phosphate also been shown to be more effective than water soluble Vitamin E in protecting against hydroxyl free radicals." In short...it is great in reducing the look of dark spots, promoting lighter, brighter skin and a more clarified skin complexion.
It is always recommended to know the ingredients in the skincare products you use. Also, make sure the first ingredient on the list is not WATER. Be on the lookout, because the vast majority of Vitamin C facial serums do contain water as its largest component.