How to Make a Vitamin C Serum: Formulating a Luminous Skin Serum

Vitamin C serums have become a cornerstone in modern skincare—but not all are created equal. When developing our Luminous Skin Serum, we set out to solve some of the most common formulation challenges: how to stabilize Vitamin C, deliver visible brightening results, and support the skin barrier without irritation.Why Vitamin C Serums Are Essential in Skincare

Vitamin C remains one of the most in-demand ingredients in skincare—and for good reason. Known for its powerful antioxidant properties, Vitamin C helps neutralize free radicals caused by UV exposure and pollution, protecting the skin from premature aging. It also plays a critical role in collagen synthesis, supporting firmer, more resilient skin over time. Perhaps most notably, Vitamin C is a proven brightener, helping to fade hyperpigmentation, even skin tone, and restore radiance.

For formulators, Vitamin C serums are a high-impact product category that delivers visible results across multiple skin concerns. Consumers continue to seek out serums with claims like "glow-boosting," "brightening," and "anti-aging"—all of which Vitamin C addresses when properly formulated.

However, formulating an effective Vitamin C serum comes with its challenges. Traditional forms like L-Ascorbic Acid are highly unstable and prone to oxidation, which can lead to reduced efficacy and unwanted discoloration. Vitamin C is also pH sensitive, requiring acidic environments to remain active, which can limit compatibility with other actives or lead to skin irritation. That’s why the choice of Vitamin C derivative—and how it's paired with other ingredients—is critical to product performance and user experience.

The power of any Vitamin C serum lies in its formulation—and the Luminous Skin Serum was built around active ingredients that deliver visible, science-backed results while working in harmony. Here’s a closer look at the key ingredients that make this serum more than just another brightening product.

L-VCG is a stabilized form of Vitamin C that retains the proven brightening and collagen-boosting benefits of L-Ascorbic Acid—without the instability and oxidation risks. As a water-soluble derivative, it is gentle on the skin, making it ideal for daily use even on sensitive skin types. It works to even skin tone, reduce dullness, and protect against environmental stressors, all while supporting collagen production for firmer, smoother skin.

Read more: Vitamin C in Skincare: Choosing the Right Form for Maximum Efficacy

We use a vectorized, encapsulated form of Centella Asiatica—Biogenics Asiaticoside-200—to enhance delivery and maximize efficacy. This advanced format not only penetrates more effectively but also provides potent anti-aging benefits. It helps boost collagen synthesis and visibly reduces the appearance of fine lines and wrinkles, while also calming the skin, making it especially beneficial in a Vitamin C formula that could otherwise be sensitizing.

GreenDiol™ serves a dual function in this formulation. As a natural humectant and emollient derived from fermented sugarcane, it deeply hydrates and improves the sensory experience of the serum. At the same time, it functions as a preservative booster, helping support the overall stability of the formula without compromising skin compatibility.

This low molecular weight version of hyaluronic acid penetrates more effectively into the skin, delivering moisture where it's needed most. It helps plump the skin, reduce the appearance of fine lines, and maintain elasticity, making it an essential partner to Vitamin C in maintaining a healthy, hydrated glow.

A multitasking ingredient loved by formulators, Niacinamide supports skin barrier repair, regulates sebum production, and minimizes the appearance of pores. In this serum, it enhances the brightening effects of Vitamin C while contributing to an overall smoother, more even skin texture. Its compatibility with other actives makes it a perfect complement to our ingredient lineup.

Read more: Best Ingredients for Glowing Skin: Vitamin C, Niacinamide, and Brightening Actives Formulators Love

We begin with distilled water and Disodium EDTA, a chelating agent that binds metal ions and helps improve the overall stability of the formula. This sets the stage for even dispersion and controlled pH during later phases.

In a separate vessel, we blend GreenDiol™—a natural humectant and emollient—with Xanthan Gum, which acts as a thickening agent to provide serum-like viscosity. Once fully mixed, Phase B is added into Phase A to create a hydrated gel base.

With the hydration base prepared, we introduce L-VCG, a stabilized form of Ascorbyl Glucoside. This water-soluble Vitamin C derivative is stirred until fully dispersed. At this stage, it’s essential to avoid heat and excessive shear to maintain ingredient integrity.

We use a sodium hydroxide solution to carefully adjust the pH of the formula to between 5.0 and 6.0. This pH range is ideal for Vitamin C stability and skin compatibility, helping to preserve the brightening efficacy over time.

Finally, we incorporate our high-performance actives—encapsulated Centella Asiatica (Biogenics Asiaticoside-200), Sodium Hyaluronate (low molecular weight), and Niacinamide—along with the preservative system (Phenoxyethanol and Ethylhexylglycerin). Each ingredient is added in order and mixed gently to preserve the structure of encapsulated ingredients.

• Hydration Time Matters: We allow the gum system to fully hydrate for 45 minutes before adding actives to ensure a smooth, consistent texture.
• pH Accuracy Is Critical: Vitamin C derivatives are still pH-sensitive—too high or too low and you risk reducing stability or irritating the skin. We strictly maintain a pH range of 5.0–6.0.
• Handle with Care: Actives like encapsulated Centella Asiatica can be disrupted with aggressive mixing. We use gentle agitation to protect their delivery systems and ensure skin performance.

The result of this carefully balanced formulation is a hazy, lightweight serum that feels as good as it performs. It spreads smoothly across the skin and absorbs quickly without leaving behind a greasy or sticky residue—making it ideal for both morning and evening routines.

Thanks to its non-tacky finish, Luminous Skin Serum layers effortlessly under moisturizers, facial oils, or sunscreen. Whether used as a standalone brightening treatment or as part of a full skincare regimen, it integrates seamlessly while delivering visible hydration, improved tone, and overall radiance.

This sensorial profile was just as important to us as the active ingredients—because high-performance skincare should feel like self-care, too.

If you’re exploring how to formulate your own Vitamin C serum, start by choosing the right form of Vitamin C for your goals. While L-Ascorbic Acid offers strong results, it can be unstable and harsh. Stabilized derivatives like Ascorbyl Glucoside (L-VCG) offer a gentler, more reliable alternative—especially when paired with a well-balanced pH and complementary actives.

Consider combining brightening ingredients like Vitamin C and Niacinamide with calming, skin-repairing actives such as encapsulated Centella Asiatica. This creates a multi-functional product that not only improves skin tone, but also supports barrier health and soothes irritation—making it suitable for a wider range of consumers, including those with sensitive skin.

Want to see the full formula?
 Download the Luminous Skin Serum Formulation Guide