Skincare Advice for Exfoliation and Your Serum

Thank you for your detailed questions and for sharing your serum formula. It's great that you are taking a holistic approach to skincare and well-being.

Regarding your questions about exfoliation and incorporating Lactic Acid, Salicylic Acid, and Azelaic Acid into your routine:

1. Which ingredient is suitable for exfoliation and melasma?

You have three excellent ingredients with different benefits:

• Lactic Acid (AHA): This is an Alpha Hydroxy Acid (AHA) that works on the skin's surface to exfoliate, improve texture, and can help with skin tone and mild hyperpigmentation like melasma. It is water-soluble.
• Salicylic Acid (BHA): This is a Beta Hydroxy Acid (BHA) that is oil-soluble, allowing it to penetrate pores effectively. It is great for dissolving clogged pores, reducing oiliness, and treating acne. It also provides exfoliation.
• Azelaic Acid (Liquid Azelaic™): This ingredient is effective for brightening skin, reducing dark spots (including melasma), controlling oil production, and reducing acne. The Liquid Azelaic™ form is water-soluble and generally gentler than traditional Azelaic Acid.

For your skin type (40+ with oily T-zone, melasma, and occasional acne), both Salicylic Acid (BHA) and Azelaic Acid could be beneficial. Salicylic Acid targets oiliness and clogged pores, while Azelaic Acid addresses both melasma and acne/oiliness. Lactic Acid is a good general exfoliant and can help with tone.

Since you have all three, you could potentially use them on different nights or choose the one that best targets your primary concern at the moment. For melasma and oil/acne control, Azelaic Acid or Salicylic Acid would be strong contenders. Using exfoliating acids can make your skin more sensitive to the sun, so consistent and sufficient sunscreen use is crucial, especially when treating melasma.

2. Can I use it before my night serum and how long should I wait?

Yes, you can apply an exfoliating toner or solution containing one of these acids before your night serum. It is generally recommended to wait a short period (around 15-30 minutes) after applying an acid exfoliant before applying subsequent products like your serum. This allows the exfoliant to work effectively at its intended pH and allows your skin's pH to normalize slightly before applying the next layer.

Your night serum formula containing Vitamin B3, Panthenol, Glucosamine, Matrixyl 3000, Argireline, and Hyaluronic Acid is a good anti-aging and hydrating formula. Applying an exfoliant first can potentially help the serum penetrate better, but the waiting time is important to minimize potential irritation.

3. Suitability, mixing with water, and concentration?

• Suitability: As mentioned, Lactic Acid, Salicylic Acid, and Azelaic Acid can all be suitable depending on your specific goals (melasma, oil, acne, general exfoliation). Consider starting with one ingredient to see how your skin reacts.
• Mixing with water: Lactic Acid (like Lactic Acid (AHA) 90% Deodorized) and Azelaic Acid (Liquid Azelaic™) are water-soluble and can be mixed with water. Standard Salicylic Acid (Salicylic Acid (BHA)) is not water-soluble and requires a solvent like Propylene Glycol or alcohol. However, there are water-soluble forms available, such as Complex Salicylic Acid (Powder, Water-Soluble) or ActiveRelease™ Salicylic Acid (Powder, Water-Soluble).
• Concentration: The appropriate concentration depends on the specific ingredient and your skin's tolerance. Always start with a lower concentration to assess sensitivity.
  • Lactic Acid (AHA) 90% Deodorized: Recommended usage rate is 1-10%, with the product pH not lower than 3.5. FDA limit for consumers is 10% at pH not lower than 3.5.
  • Salicylic Acid (BHA): FDA allows up to 2% for leave-on products. If using a water-soluble powder form like Complex Salicylic Acid (40% active), you can use up to 5% of the powder (which provides 2% active Salicylic Acid).
  • Azelaic Acid (Liquid Azelaic™): Recommended usage rate is 5-10%. The product description recommends 10% for brightening and oil control.

Creating a multi-functional toner with multiple strong actives like these requires careful formulation to balance effectiveness with potential irritation. Given your concern about over-treating your skin, it is wise to proceed cautiously. Starting with a single active ingredient at a low concentration and gradually increasing as your skin tolerates it is a recommended approach. You can then observe how your skin responds and decide if adding another active on different nights or in a separate product is necessary.

Remember that while exfoliation can help with cell turnover and improve the appearance of melasma and acne, consistent sun protection is the most critical factor in managing melasma and preventing it from worsening.

I hope this information helps you in formulating your skincare products!