Vitamin C is a natural antioxidant component of the outermost layers of healthy skin. It has many benefits including:
-Increasing collagen synthesis
-Evening out skin tone
-Diminishing appearance of fine lines and wrinkles
-Helping to prevent and treat uv induced, photo damaged skin
-Helping to protect from environmental stressors such as pollution and uv exposure
-Has been shown to be anti-inflammatory and help promote wound healing
As we age, the levels of Vitamin C in skin begin to decline. Exposure to environmental stressors also depletes Vitamin C leaving our skin more vulnerable to photo damage caused by free radicals and other stressors.
While internal supplementation of C is a helpful health aid, the most effective way to increase Vitamin C levels in skin is through topical application with properly formulated Vitamin C products. There are many different forms of Vitamin C, some more stable than others and with better absorption.
We’ll highlight 4 popular forms/derivatives here:
Ascorbyl Tetraisopalmitate (ATIP)
An oil-soluble derivative of C. This is the form we use in The Clarity Oil. One of the most expensive and stable forms of Vitamin C on the market with more efficacy data and faster absorption than any alternative. It is also much gentler and remains in the skin cells 40-80 times longer than L-Ascorbic acid.  It’s often mistakenly labeled Tetrahexyldecyl Ascorbate (THD). These are not the same Vitamin C derivatives as they have different chemical structures.
Tetrahexyldecyl Ascorbate (THD Ascorbate)
An oil-soluble derivative of C. Similarly to Ascorbyl Tetraisopalmitate, it is also extremely stable and gentle with good penetration.
Sodium Ascorbyl Phosphate (SAP)
Water-soluble, gentle, light and oxygen stable form of Vitamin C. Research shows that concentrations between 1-5% of SAP can be efficient in the prevention and treatment of acne. 
L-Ascorbic Acid (L-AA)
Water-soluble. One of the most effective forms of Vitamin C but also the least stable, most prone to oxidation and can aggravate sensitive skin. When using products with L-Ascorbic acid, make sure they are housed in air-tight, opaque packaging and use with a gentle routine.
Vitamin E & Vitamin C, Better Together
This dynamic duo, Vitamin E (tocopherols, tocotrienols) and Vitamin C work synergistically to protect from uv damage better than either used alone.  For maximum benefits, look for products that contain both.
It’s important to note that while Vitamin C has antioxidant activity that helps protect against UV damage, it is also not a sunscreen and cannot replace the need for sunscreen. Using Vitamin C products in conjunction with SPF is beneficial though and helps to give broader protection.
Photo credit Kimberly Miller
 Pullar, J., Carr, A., & C. M. Vissers, M. (2017, August 1). The Roles of Vitamin C in Skin Health. PubMed Central (PMC). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5579659/
 stamford, n. (2012). stability, transdermal penetration, and cutaneous effects of ascorbic acid and its derivatives. journal of cosmetic dermatology, 11(4), 310-317. doi: 10.1111/jocd.12006
 Klock, J. (2005, June 27). Sodium ascorbyl phosphate shows in vitro and in vivo efficacy in the prevention and treatment of acne vulgaris. PubMed. https://pubmed.ncbi.nlm.nih.gov/18492184/
 Lin, J. (2003, June). UV photoprotection by combination topical antioxidants vitamin C and vitamin E. PubMed. https://pubmed.ncbi.nlm.nih.gov/12789176/