Calculating Glycolic Acid Percentage in Your Formula

Thank you for your question regarding the use of Glycolic Acid powder (Glycopure™).

Based on the information provided and the clarification from our staff, the percentage of an ingredient in a cosmetic formula, such as Glycolic Acid, is calculated based on the total weight of the final formula, not just the water phase or other individual components.

Here's a breakdown to address your questions:

1. Amount of Glycolic Acid Powder: To achieve a specific percentage of Glycolic Acid in your total formula, you should calculate the amount based on the desired percentage of the final formula weight. For example, if you want a 10% Glycolic Acid concentration in a 100g total formula, you would add 10g of Glycolic Acid powder. The remaining 90g would be the total weight of all other ingredients, including water.

2. Your Calculation (5.2g + 46.8ml): Your calculation of 5.2g Glycolic Acid powder + 46.8ml water results in a total of approximately 52g (assuming water density is 1g/ml). If this 52g mixture is then used as part of a larger formula, the percentage of Glycolic Acid in the final formula would be (5.2g / Total Formula Weight) * 100%. If this 52g mixture represents 52% of your total formula (meaning your total formula is 100g), then the Glycolic Acid concentration in the final formula is 5.2g in 100g, which is 5.2%, not 10%. Therefore, this calculation is incorrect for achieving 10% Glycolic Acid in the total formula.

3. Basis for Calculation: The calculation should be based on the total weight of the final formula, not just the water phase or net volume.

In summary: If you aim for a 10% Glycolic Acid concentration in your final product, you need to add Glycolic Acid powder equivalent to 10% of the total weight of your formula. The remaining 90% of the formula will consist of all other ingredients.