Using Stabilized Vitamin C with Your Current Formulation

It's great that you are actively formulating to address your skin concerns! Let's look at how you can incorporate Stabilized Vitamin C (Natural-C Glycol™) Serum into your routine and address your other questions.

Compatibility with Your Current Cream

Your current cream formulation contains several beneficial ingredients:

• Tranexamic Acid (Trans-White™): Known for reducing hyperpigmentation and blemishes.
• GlucoBright™ (Acetyl Glucosamine) & Safe-B3™ (Vitamin B3, Niacinamide): This combination is effective for brightening, reducing dark spots, improving skin texture, stimulating hyaluronic acid production for moisture, and reducing oiliness and acne breakouts.
• Licorice Extract (Licochalcone A): Helps reduce skin inflammation, redness, irritation, and oiliness, which is beneficial for acne-prone skin.
• Witch Hazel: Acts as an astringent to help tighten pores.
• Mild Preserved Eco™ (Ethylhexylglycerin): A gentle preservative.
• Reservoir-Tech: Helps active ingredients penetrate and stay in the skin longer, potentially reducing irritation.
• Light Cream Maker™: Provides the cream texture.

The Stabilized Vitamin C (Natural-C Glycol™) Serum is a ready-made base containing 15% L-Ascorbic Acid in a glycol base. The product description indicates it is not suitable for mixing additional ingredients (except fragrance and color) as it may affect its stability. Therefore, you should not mix the Stabilized Vitamin C (Natural-C Glycol™) Serum directly into your existing cream formulation.

How to Use Stabilized Vitamin C and Your Cream

Since you should not mix them, you can apply them as separate layers in your routine. The Stabilized Vitamin C (Natural-C Glycol™) Serum contains L-Ascorbic Acid, which is sensitive to light and air. While this specific product is stabilized, applying it at night is generally recommended to maximize its efficacy and minimize potential interactions with daytime environmental factors or sunscreen ingredients like Zinc Oxide, as mentioned in the staff reply regarding L-Ascorbic Acid.

Your current routine of using your cream formulation at night and Vitamin C in the morning is the opposite of what is generally advised for L-Ascorbic Acid stability and potential interactions with sunscreen. It would be better to apply the Stabilized Vitamin C (Natural-C Glycol™) Serum at night after cleansing and before your cream. Allow the serum to absorb for 15-30 minutes before applying your cream, as suggested by the staff, to ensure optimal absorption of the Vitamin C.

In the morning, you can use your cream formulation followed by sunscreen (like your Nivea SPF50 PA++). Your cream contains ingredients like Niacinamide and Licorice Extract which can help control oiliness throughout the day.

Addressing Skin Concerns and Hydration Balance

Your current cream formulation already includes excellent ingredients for addressing your concerns with acne, oiliness, marks, and texture (Tranexamic Acid, Niacinamide, Acetyl Glucosamine, Licorice Extract, Witch Hazel). Adding the Stabilized Vitamin C (Natural-C Glycol™) Serum at night will further enhance brightening, stimulate collagen for scar improvement, and provide antioxidant benefits.

You mentioned your skin feels oily during the day but dry at night in an air-conditioned room. Your current cream uses Light Cream Maker™, which provides a light texture and might not be sufficient for nighttime hydration, especially in a dry environment. To balance your skin's hydration, especially at night, consider applying a separate, more moisturizing product after your Stabilized Vitamin C serum and your current cream. As suggested in the forum replies, Galactomyces Ferment Filtrate is an excellent ingredient for improving skin texture, hydration, and overall skin health, and could be used as a separate serum or added to a more moisturizing base for nighttime use.

Stinging and Sensitive Skin

You experienced slight stinging with Vitamin C (L-Ascorbic Acid). This is a common sensation, especially with L-Ascorbic Acid, due to its acidic nature and concentration. The Stabilized Vitamin C (Natural-C Glycol™) Serum contains 15% L-Ascorbic Acid, which is a high concentration. While the stabilization helps, it may still cause a tingling or stinging sensation, particularly on sensitive or compromised skin. Licorice Extract in your cream can help soothe irritation. If the stinging is significant or persistent, it might indicate that the concentration is too high for your skin. You could try reducing the frequency of application (e.g., every other night) or consider a Vitamin C derivative that is less acidic if the irritation persists. Always perform a patch test when introducing new products, especially those with high concentrations of active ingredients.

In summary, do not mix the Stabilized Vitamin C Serum into your cream. Apply the Stabilized Vitamin C Serum at night, followed by your cream, and consider adding a separate moisturizer or an ingredient like Galactomyces Ferment Filtrate at night for better hydration balance. Continue using your cream and sunscreen in the morning. Be mindful of potential stinging from the high concentration of Vitamin C and adjust usage as needed.