Our Lucent-C Vitamin C Serum 15% enhances the visual radiance, luminosity, and lucency of the skin while improving firmness and elasticity. It contains 15% l-ascorbic acid, the most biologically available and well studied form of vitamin C. The L refers to the spatial isomer or enantiomer of ascorbic acid that the skin identifies and can use to improve the overall complexion and firmness of the skin. L-ascorbic acid is a multifunctional antioxidant that topically brightens the skin, reduces photoaging, reduces the look of post inflammatory hyperpigmentation, and optically improves fine lines and wrinkles. Learn more about the benefits of Vitamin C. The efficacy of l-ascorbic acid has been thoroughly validated and proven but the efficacy of this molecule in a cosmetic product is critically dependent on the formula composition.

L-ascorbic acid has both difficulty penetrating the superficial layers of skin as well as maintaining its active form. These concerns are addressed through formulation, packaging considerations, storage conditions, and shelf life. Reducing the pH of a water based l-ascorbic acid formula below pH 3.5 improves the permeability and stability of this molecule by keeping it in its uncharged form. Ingredients such as ferulic acid can be added to the formula to aid in reducing the overall pH of the formula as well as enhance l-ascorbic acid stability. Our formula features 0.5% ferulic acid at a formula pH of 3.20+/-. This combination of pure low molecular weight antioxidants provides meaningful synergistic protection against oxidative stress and photoaging.

The efficacy of our Lucent-C Vitamin C Serum 15% is also optimized with the combined use of ethoxydiglycol and propanediol. Ethoxydiglycol and propanediol function as solvents and excipients that support dissolution into the skin while encouraging water retention in the skin. They decrease the charge of the molecule by a solvent effect and increase the solubility and partitioning in the stratum corneum without disturbing the lipid bilayer structures. This is crucial as some excipients acting as penetration enhancers temporarily change the crystallinity and structure of the lipid layer or even remove part of the lipid layer to increase penetration of an ingredient. This compromises the skin barrier and can lead to irritation and transepidermal water loss. Propanediol and ethoxydiglycol also reduce water activity in the formula which is significant because decreasing the water activity or moisture content in the formula decreases the degradation rate of l-ascorbic acid. Water content, heat, light, and oxygen exposure increase the oxidation of l-ascorbic acid to dehydroascorbic acid which can then oxidize to 2,3-diketogluconic acid. Our formula is in an opaque, airtight container to minimize light and excess oxygen exposure while solvents ethoxydiglycol and propanediol reduce water activity.

While oxidation can’t be completely avoided, we added ergothehionene, a sulfur-containing amino acid, to act as a sacrificial antioxidant. It helps maintain the efficacy of the formula by increasing the amount of active vitamin C through recycling oxidized vitamin C back to the active l-ascorbic acid form. We also included niacinamide to target uneven skin tone, which can be used safely at this low pH and in combination with l-ascorbic acid without hydrolysis to niacin.

To ensure optimal performance of our Lucent-C Vitamin C Serum 15%, we conducted assay testing on the formula produced on a large scale and filled in our packaging. Assay testing entails identifying the percent or activity of an ingredient in a formula at directed timepoints to ensure the formula contains the claimed level of said active ingredient and therefore maintains its efficacy. Our assay testing was not only performed initially upon production but over a 6M time frame. Our analytical lab does not first reduce dehydroascorbic acid (oxidized l-ascorbic acid) to l-ascorbic acid prior to doing the assay measurement. We do not have this reduction step as part of our methodology that can skew the data falsely giving higher l-ascorbic acid readings. Based on our stability and assay testing we recommend using your product within 3 months of opening, a PAO of 3 months. This provides sufficient time to use the product fully and start seeing cosmetic results. Results start around 4 weeks but best results are achieved within 8 weeks applying the product once per day. As always, wear sunscreen so you don’t undo your progress. The color of our serum can vary from clear to pale yellow due to the shift in color of the actives over time but that does not mean the product is ineffective. To slow this color shift you can refrigerate your Lucent-C Vitamin C Serum 15%.

Our Lucent-C Vitamin C Serum 15% can be used for a number of reasons: post breakout to reduce post inflammatory hyperpigmentation, post procedure to minimize the visual appearance of hypertonic and keloidal scarring, after microneedling to optically improve stretch marks, prior to sunscreen application to minimize free radical damage that causes premature skin aging, and use at night to replenish depleted levels of vitamin C in the skin.

The Lucent-C Vitamin C Serum 15% is alcohol-free, fragrance-free, dermatologist-developed, dermatologist-tested, and allergy tested.

DISCLAIMER: All skin care articles are intended to help educate on specific ingredients and skin care topics. Our articles are written to be informative and informational. Any reference to a specific patient experience is not a medical suggestion for treatment. Please note that any Prequel products with referenced ingredients are formulated for Cosmetic Use Only and NOT intended as replacements for physician advice and/or pharmaceutical product recommendations.