L-ascorbic acid is the purest form of Vitamin C and is widely regarded as the most effective for skincare. It works as a potent antioxidant, protecting the skin from free radicals caused by UV exposure and pollution. 

DrLOUIE Vitamin C Serum’s 20% L-ascorbic acid concentration ensures your skin receives a high dose of this active ingredient, promoting collagen production, brightening skin tone, and reducing signs of aging.

Compared to other forms of Vitamin C, L-ascorbic acid is more bioavailable and penetrates the skin more effectively. While derivatives are often more stable and less likely to cause irritation, they must convert to L-ascorbic acid in the skin to become active, which can reduce their efficacy. 

Click here to read about why Dr. Louie Kim used L-Ascorbic Acid for his Vitamin C Serum.

Anyone looking to improve their skin’s overall health and appearance can benefit from Vitamin C serum. 

Who it's good for:

• dull skin
• hyperpigmentation
• fine lines, and
• uneven texture. 

DrLOUIE Vitamin C Serum is suitable for all skin types, including sensitive skin, thanks to its carefully balanced formulation, using panthenol, an ingredient known to strengthen skin barrier. 

Yes, Vitamin C can be combined with many active ingredients, but it’s essential to proceed with caution. For instance, it pairs well with hydrating ingredients like hyaluronic acid, which helps to lock in moisture, and niacinamide, which can improve the skin’s barrier function. However, there are certain active ingredients that should be avoided or used carefully:

• Avoid Combining with Retinol: Both Vitamin C and retinol are powerful actives but can irritate the skin when used together due to their differing pH requirements. To use both, apply Vitamin C serum in the morning and retinol at night.

• Be Cautious with AHAs/BHAs: Acids like glycolic acid, salicylic acid, and lactic acid can lower the skin’s pH further, potentially destabilizing Vitamin C and increasing irritation. It’s best to use these ingredients at separate times of the day.

• Pair with Sunscreen: Vitamin C enhances the effectiveness of your sunscreen by neutralizing free radicals. Always follow your Vitamin C serum with a broad-spectrum SPF in the morning.

By understanding these combinations, you can maximize the benefits of Vitamin C Serum while avoiding unnecessary irritation.

Click here to learn more about ingredient combinations to avoid to keep your skin barrier healthy. 

Consistency is key when using Vitamin C serum. 

While some users notice brighter skin within a few days, it generally takes 4-6 weeks of regular use to see significant improvements in skin texture, tone, and firmness. 

The high concentration of L-ascorbic acid in DrLOUIE Vitamin C Serum accelerates these results by delivering potent antioxidant benefits to your skin.

High concentrations of L-ascorbic acid, like the 20% in our Vitamin C Serum, can sometimes cause a tingling sensation, especially for first-time users or those with sensitive skin. This is normal and should subside as your skin builds tolerance. 

However, it is important to note that concentrations higher than 20% do not necessarily increase effectiveness and are more likely to cause irritation. 

Research shows that 20% is the optimal concentration for delivering maximum benefits while maintaining a balance between efficacy and tolerability. 

If you experience redness or irritation, reduce usage to every other day and gradually increase frequency as your skin adapts.

Vitamin C serum is most effective when used in the morning. (Click here to read more in-depth about this.)

Its antioxidant properties help protect your skin from environmental stressors like UV rays and pollution throughout the day. That said, you can also use it at night to enhance your skin’s repair process. 

DrLOUIE Vitamin C Serum’s stable formulation ensures efficacy regardless of the time of day.

Proper storage is crucial to maintain the potency of Vitamin C serum. Exposure to light, heat, and air can degrade L-ascorbic acid. DrLOUIE Vitamin C Serum is packaged in an opaque, airless pump bottle to minimize oxidation. Keep the serum in a cool, dark place to ensure its effectiveness over time.

Click here to learn more about what our research team found about storing Vitamin C Serum and tips. 

Vitamin C works wonders for both dull skin and hyperpigmentation. When your skin looks dull, it’s often due to a buildup of dead skin cells and a lack of hydration. Vitamin C helps brighten your skin by encouraging cell turnover, which replaces old, dull skin cells with fresh, glowing ones.

For hyperpigmentation, Vitamin C inhibits an enzyme called tyrosinase, which is responsible for producing melanin—the pigment that causes dark spots. By reducing melanin production, Vitamin C fades existing dark spots and prevents new ones from forming. DrLOUIE Vitamin C Serum’s 20% L-ascorbic acid concentration works efficiently to address these issues, leaving your skin more even-toned, radiant, and full of life.

1) 20% L-Ascorbic Acid at pH Level < 3.5

The amount we use is enormous: 20%, meaning 200,000ppm! That means there is that much more Vitamin C fighting off free radicals to protect our skin cells. This would maximize anti-aging effects of the Serum from the moment you open it to the moment you finish the bottle. Not only that, according to literature, 20% is the best and maximum concentration of L-Ascorbic Acid to show maximum results: anything higher than 20% can actually irritate the skin without an increase in effectiveness.

2) Actual Penetration in the Skin

Although L-Ascorbic Acid is the most biologically active and well-studied form of Vitamin C, it has poor skin penetration. Studies have found that a pH level of below 3.5 increased not only stability but also penetration into the skin.

DrLOUIE Vitamin C Serum is formulated at below pH Level of 3.5. In addition, we use an excellent carrier ingredient, known as allantoin, which helps the ingredient actually get absorbed into the skin. 

In addition, our unique formula allows part L-Ascorbic Acid to get penetrated into the skin superbly while allowing other part to stay on top of the skin. What this means is that L-Ascorbic Acid that gets penetrated into the skin helps to brighten the skin from inside, and the remaining would protect the skin against free radical damage and skin oxidization.

3) Double Antioxidant & Brightening Power - EmblicaTM

In addition, we use EmblicaTM, a patented ingredient for reducing hyperpigment and brightening the skin to increase synergy with L-Ascorbic Acid.

When used together, they not only show enhanced antioxidant shield, but also display a more comprehensive skin brightening. L-Ascorbic Acid and EmblicaTM have different mechanisms to inhibit melanin production: EmblicaTM helps regulate cells responsible for producing melanin while L-Ascorbic Acid interrupts melanin production process.

4) Superb Hydration - Panthenol and Mixed Molecular Weight Hyaluronic Acid

For L-Ascorbic Acid and EmblicaTM to help brighten the skin and show anti-aging effects, it's essential for the skin to be hydrated, which is the foundational factor. So we've used a high concentration of panthenol to help build skin barrier and mixed molecular weight hyaluronic acid to keep the skin hydrated.

5) Irritation-Free & Safe

• Dermatest Certification: The serum has earned an "Excellent" rating from Dermatest, a prestigious certification that involves rigorous testing to ensure that the product does not cause irritation or allergic reactions. This rating indicates that the serum is unlikely to cause irritation even on sensitive skin, making it a reliable choice for those with reactive or easily irritated skin.
• EWG Verified: The Environmental Working Group (EWG) Verified seal is a mark of transparency and safety. Products with this verification have undergone strict evaluations to ensure they do not contain harmful chemicals and are safe for consumer use. DrLOUIE Vitamin C Serum’s EWG Verification underscores its commitment to using safe, non-toxic ingredients.