Formula Feedback and Recommendations

Based on your formula and skin concerns (not very bright, moderately oily, some acne), here's an evaluation and some recommendations:

Your current formula includes:

• Vit B3 (Niacinamide) 4%
• NAG (N-Acetyl Glucosamine) 4%
• Azelaic acid 10%
• Lactic Acid (AHA) (for pH adjustment to 5.5)
• Hyaluronic acid 0.5 %
• Distilled water

This is a good base formula targeting brightening, clarity, and hydration. The combination of Niacinamide, N-Acetyl Glucosamine, and Azelaic acid is effective for improving skin tone and texture.

Evaluation and Recommendations:

1. Niacinamide (Vit B3) 4%: This is an excellent concentration for brightening, reducing redness, improving skin barrier, and helping with oil control. Products like Safe-B3 or Extreme-B3 are suitable sources.
2. NAG (N-Acetyl Glucosamine) 4%: A great partner to Niacinamide for addressing hyperpigmentation and promoting hydration by stimulating hyaluronic acid production in the skin. GlucoBright is a relevant ingredient.
3. Azelaic acid 10%: This is a potent ingredient for brightening, reducing inflammation, and helping with acne and oiliness. However, as the staff mentioned, 10% can be irritating, especially if your skin is sensitive or new to this ingredient. Given your skin type (some acne, moderately oily), it's beneficial, but starting at 5% (using a product like Liquid Azelaic) or patch testing the 10% is a wise precaution. You can gradually increase the concentration if your skin tolerates it well.
4. Lactic Acid (AHA): Using Lactic Acid to adjust pH to 5.5 is appropriate for creating a skin-compatible environment. At this pH, its primary role is pH adjustment rather than significant exfoliation, which can help minimize potential irritation from the other actives. Options include Lactic Acid Neutralized or Lactic Acid 90%.
5. Hyaluronic acid 0.5%: This is a good concentration for providing hydration without feeling heavy, which is important even for oily skin. Various types of Hyaluronic Acid, such as Standard Molecule, Small Molecule, or Large Molecule, can be used.
6. Licorice Extract: The staff's suggestion to add Licorice extract is highly recommended for your skin type. Licorice extract (such as the water-soluble type or those standardized for Glabridin or Licochalcone A) has anti-inflammatory properties, helps reduce redness from acne, and can assist with oil control and brightening. Adding it (typically at 0.5-2%) would complement the other ingredients well.

Additional Considerations:

• Full Formulation: Remember that a complete formula requires a preservative system to ensure stability and prevent microbial growth, especially since it's a water-based product. You may also need a thickener or gelling agent to achieve your desired texture (serum, gel, etc.) and potentially chelating agents for stability.
• Skin Sensitivity: With multiple active ingredients, there is a higher chance of irritation. Always perform a patch test before applying the formula to your entire face. Introduce the product gradually into your routine.
• Current Products: Be mindful of the other products you are using (Olay Natural White, Pond's Flawless White, Smooth E Babyface Gel, Clindalin Gel). Combining multiple active treatments can increase the risk of irritation. Observe your skin's reaction carefully.

Overall, your formula is well-designed for your goals. Adjusting the Azelaic acid concentration based on your skin's tolerance and adding Licorice extract would be beneficial modifications. Ensure you include necessary base ingredients like a preservative for safety and stability.