Understanding pH in Your Formulation

You're asking about the pH impact of Sodium Lactate and whether Lactic Acid is needed for adjustment.

• Sodium Lactate: As correctly noted in the reply you received, Sodium Lactate is not an acid. It is a salt of Lactic Acid and has a near-neutral pH, typically ranging from 6.5 to 7.5. Its primary role in your formulation at 3% is as a humectant, helping to moisturize the skin. While Sodium Lactate can contribute to skin cell turnover at concentrations above 3%, its main function at this level is hydration.
• L-Carnitine: The product information for L-Carnitine indicates it has a pH range of about 7.5-9.5, and at a 3% concentration, its pH is around 7.5. It is described as an amino acid that helps accelerate skin cell turnover without being acidic, working effectively in a pH range of 6-7.
• Combined pH: When you combine L-Carnitine (pH ~7.5) and Sodium Lactate (pH ~6.5-7.5) in your formulation, along with other ingredients, the initial pH of the mixture will likely be in the neutral to slightly alkaline range, probably above your target pH of 5.5.

Therefore, based on the pH of L-Carnitine and Sodium Lactate, you will still need to use an acid like Lactic Acid or Citric Acid to lower the pH of your final formulation to the target of 5.5. The product description for L-Carnitine also suggests using acids like citric acid or lactic acid to adjust the pH down to the skin-suitable range of 4-7.

Other Ingredients

• Lemon Oil: You are correct that Lemon Oil is typically an essential oil. It is often used for its fragrance and potential stimulating properties, which some believe can help with the appearance of cellulite, although L-Carnitine is more widely recognized for this claim.
• Urea and Sodium PCA: Adding Urea and Sodium PCA is an excellent way to boost the moisturizing capabilities of your gel. These ingredients, along with Sodium Lactate, are key components of the skin's Natural Moisturizing Factor (NMF) and work synergistically to hydrate the skin effectively.
• Pro Polymer and Electrolytes: Be aware that ingredients containing electrolytes, such as Sodium Lactate and Sodium PCA, can affect the viscosity of gels made with Pro Polymer. The product information for Pro Polymer mentions that electrolytes can soften the gel texture. Your mixing method of adding the other ingredients to the pre-formed gel is appropriate, but you may find that you need to adjust the amount of Pro Polymer or add a little more after incorporating the Sodium Lactate and Sodium PCA to achieve your desired gel consistency.

In summary, Sodium Lactate is not acidic and primarily provides moisturizing benefits at 3%. Your formulation containing L-Carnitine and Sodium Lactate will likely require pH adjustment with an acid like Lactic Acid to reach your target pH of 5.5. Adding Urea and Sodium PCA will enhance the moisturizing effect, but be mindful of their impact on the gel's viscosity.