Skincare Formulation Feedback for Brightening and Firming

Thank you for sharing your proposed skincare formulation. It's great that you are exploring making your own products! Based on your goals for brightening and firming, and considering your skin type (dry to combination, occasional acne, dullness, no wrinkles yet), the ingredients you've chosen are well-selected.

Here is some feedback on your formula and questions:

Ingredient Suitability and Concentration

• N-Acetyl-D Glucosamine (4%) and Vitamin B3 (5%): These are excellent choices for brightening and improving skin tone. N-Acetyl-D Glucosamine (like GlucoBright™) works synergistically with Vitamin B3 (like Safe-B3™) to reduce hyperpigmentation and stimulate hyaluronic acid production for hydration. The concentrations you chose are within the recommended ranges and should be effective.
• Natto Gum (5%): As mentioned in the previous reply, Natto Gum (Nutto Gum) is a powerful moisturizer, even more so than hyaluronic acid according to some research. While great for dry skin, 5% might feel a bit heavy for combination skin, especially in areas prone to oiliness or acne. You might consider reducing the percentage slightly (e.g., to 3-4%) if you find the texture too rich or if it contributes to breakouts in your T-zone. It also offers gentle whitening benefits.
• Licorice Extract (1%): Licorice Extract is known for its anti-inflammatory and soothing properties, which can help with occasional acne and reduce redness. It also has some brightening effects. 1% is a suitable concentration.
• Matrixyl™ 3000 (5%): This peptide blend (like Pal-GHK, Pal-GQPR) is excellent for stimulating collagen synthesis and improving skin elasticity, addressing your goal for firmness. 5% is at the higher end of the recommended range (3-5%), which is good for targeting firmness.
• Perfect-C™ (Ascorbyl Tetraisopalmitate) (2%): This oil-soluble Vitamin C is stable and effective for brightening, antioxidant protection, and collagen stimulation. 2% is the minimum concentration recommended for whitening effects in Korea, so it will contribute to your brightening goal.
• Activated Resorcinol™ (4-Butyl Resorcinol) (1%): Activated Resorcinol™ is a potent skin brightener that works by inhibiting tyrosinase activity. 1% is the maximum recommended concentration for leave-on products due to its potency. It is effective for reducing dark spots and improving overall radiance.
• LipidSoft (5%): LipidSoft is a group of emollients that provide a smooth feel and help dissolve oil-soluble ingredients like Perfect-C™ and Activated Resorcinol™. 5% is a reasonable amount for the oil phase.
• EDTA (0.2%): Including a chelating agent like EDTA (or Disodium Etidronate) is good practice, especially when using ingredients like Vitamin C, as it helps stabilize the formula by binding to metal ions.
• Light Cream Maker (1%): This emulsifier helps create the cream texture by blending the water and oil phases.
• Phenoxyethanol (1%): This is a common and effective preservative used to prevent microbial growth in the formula.

pH Measurement

Regarding your question about pH measurement, the previous reply is correct. With the ingredients you have chosen, the resulting pH is likely to be in a range suitable for skin (neutral to slightly acidic, generally between 4.0-7.0 depending on the specific raw materials). While measuring pH provides an extra layer of control and is recommended for advanced formulation, for a personal-use formula with these ingredients, it is not strictly necessary to achieve a functional product. However, if you plan to make formulations with ingredients that require a very specific pH range for stability or efficacy (like some forms of Vitamin C or AHAs), a pH meter would be beneficial.

Mixing Steps

The mixing steps you outlined are generally correct for creating an emulsion (cream). Ensure both water and oil phases are at similar temperatures before combining, and mix thoroughly after adding the water phase to the oil phase with the Light Cream Maker.

Overall Assessment

Your formula is well-designed with multiple active ingredients targeting brightening (N-Acetyl-D Glucosamine, Vitamin B3, Licorice Extract, Perfect-C™, Activated Resorcinol™) and firming (Matrixyl™ 3000). The combination of water and oil-soluble actives allows for a comprehensive approach. Pay attention to how the 5% Natto Gum feels on your combination skin and adjust if needed. The inclusion of EDTA and Phenoxyethanol addresses stability and preservation.

This formula appears promising for addressing your skin concerns.