Formula Review and Recommendations

Your formula includes several effective ingredients for exfoliation, anti-aging, and antioxidant benefits, targeting your skin concerns of oiliness, fine lines, and smile lines.

Based on the concentrations and ingredient properties:

• Glycolic Acid (10%): This is a high concentration for a leave-on product intended for general consumer use (FDA recommends max 5%). While you are used to 8% AHA, jumping to 10% Glycolic Acid (which has the smallest molecule and penetrates well) might cause significant irritation, even if your skin isn't easily irritated. As the staff reply suggested, starting at 5% is highly recommended to see how your skin tolerates it before gradually increasing the concentration if needed.
• DMAE (SkinTight MD™) Liquid (10%): This is at the higher end of the recommended usage range (1-10%). Like Glycolic Acid, starting at a lower concentration, such as the 5% recommended by the staff, is advisable, especially if you haven't used DMAE before. Higher concentrations can increase the risk of irritation and contribute significantly to product stickiness.
• Wrinkle-Fill™ (L-Tyrosine) (2%): This is within the recommended usage rate (1-2%). It works well with DMAE for anti-aging benefits.
• WhiteCumin™ 2x (2.5%): This is within the recommended usage rate (1-4%) and provides antioxidant benefits.
• Panthenol (Pro Vitamin B5) (2.5%): This is within the recommended usage rate (0.5-10%) and is excellent for hydration, soothing, and can enhance the effect of DMAE. However, Panthenol can also contribute to stickiness at higher levels (>5%).
• 1,2-Hexanediol (3%): This concentration is effective as a preservative booster, penetration enhancer, and humectant.
• Disodium EDTA (0.2%): This is the recommended usage rate for chelating metal ions.

The combination of 10% Glycolic Acid, 10% DMAE, and 2.5% Panthenol is likely to result in a formula that is quite sticky, as noted by the staff. Reducing the Glycolic Acid and DMAE concentrations to 5% initially would help mitigate this and reduce the risk of irritation.

Your mixing method of adding Disodium EDTA to water, followed by 1,2-Hexanediol, and then other ingredients sequentially is generally correct for water-soluble ingredients. However, it's important to add DMAE in the final step and ensure the temperature of the mixture is below 40°C when you add it, as high heat can affect its stability. Glycolic Acid should also avoid heat above 60°C.

Answers to Your Questions

1. Are there any necessary adjustments to the ingredients and mixing method?

   • Ingredients: Yes, it is strongly recommended to reduce the concentration of Glycolic Acid and DMAE. Start with 5% Glycolic Acid and 5% DMAE to assess skin tolerance and reduce potential irritation and stickiness. You can gradually increase the concentration later if your skin responds well and you desire stronger effects. The other ingredient percentages are within typical recommended ranges.
   • Mixing Method: Your method is mostly correct. Ensure that DMAE is added as the very last ingredient after the mixture has cooled down to below 40°C. Avoid heating the mixture above 60°C after adding Glycolic Acid.

2. If using Distilled Water ordered from the company, is it still necessary to add 2Na EDTA?

   • Yes, it is still beneficial to include Disodium EDTA even when using distilled water from the company. While distilled water is pure, EDTA helps to chelate any trace metal ions that might be present or introduced during the mixing process or from packaging. This helps to maintain the stability of the formula and prevent potential discoloration or degradation of sensitive ingredients over time, extending the product's shelf life.

3. If the product shelf life is not more than 6 months, can 1,2-Hexanediol be used as a preservative?

   • 1,2-Hexanediol at 3% acts as a preservative booster and has some antimicrobial properties on its own, as shown by passing a Challenge Test. For a personal-use product targeting a 6-month shelf life, 3% 1,2-Hexanediol might be sufficient to prevent microbial growth, but it is not guaranteed without performing a challenge test on your specific formula. For better reliability and safety over 6 months, it is highly recommended to include a small amount of a mild, broad-spectrum cosmetic preservative alongside the 1,2-Hexanediol. 1,2-Hexanediol will enhance the effectiveness of the added preservative, allowing you to use a lower concentration of the main preservative.

4. What pH range does WhiteCumin™ 2x work well in? (If the pH of this formula is controlled at 3.5, will WhiteCumin™ 2x lose effectiveness?)

   • As confirmed by the staff reply and the product information, WhiteCumin™ 2x works well in a pH range of 3.5 to 6.5. Controlling the pH of your formula at 3.5 is within this optimal range, so WhiteCumin™ 2x will not lose effectiveness at this pH.

In summary, consider reducing the concentrations of Glycolic Acid and DMAE to 5% initially for better skin tolerance and reduced stickiness. Ensure DMAE is added last at a low temperature. Keep the Disodium EDTA for stability. For a 6-month shelf life, consider adding a small amount of a dedicated preservative in addition to the 1,2-Hexanediol for more reliable microbial protection. The pH of 3.5 is suitable for WhiteCumin™ 2x.