Body Mask Formulation with High AHA/BHA Concentration: Mixing, pH, and Preservation

Question

I want to make a body mask using the following formula:

Water 30%
Ethyl Alcohol 20%
Glycerin 20%
Willow Bark Extract (Natural Salicylic Acid) 10%
Lactic Acid (AHA) 88% 10%
Glycolic Acid (AHA) 100% Powder 10%

This formula uses a total acid concentration of 30%. I understand the risks associated with high concentrations and the staff's recommendation to use only Glycolic Acid 5% for home use, but I want to proceed with this specific formula.

Could you please provide guidance on the following:

What is the correct mixing procedure for these ingredients? Should anything be added before or after others?
How should this formula be stored? Does it need to be kept in the refrigerator?
Is it necessary to include a preservative in this formula?
Is it necessary to purchase a pH meter when making this formula, or is it not needed?

MySkinRecipes Expert · Accepted Answer

Hello,

I understand that you would like to create a body mask formula based on the ingredients you provided, which primarily contain exfoliating acids (AHA/BHA) along with other ingredients.

Regarding your question about the percentage of the acid ingredients (Willow Bark Extract, Lactic Acid, Glycolic Acid) which you proposed at 10% each, totaling 30%, and whether you can use a higher concentration:

The staff has previously advised that using a high concentration of acids up to 30% is suitable only for medical professionals who have the knowledge to assess skin condition and response to avoid the risk of irritation or skin damage.

For home use, the staff recommends using only Glycolic Acid at a concentration of 5% as a safer option that will provide good results over the long term.

However, if you decide to proceed with the formula containing a total acid concentration of 30% as you proposed (Willow Bark Extract 10%, Lactic Acid 10%, Glycolic Acid 10%), please be aware of the risks as warned by the staff, and you assume responsibility for any potential outcomes.

For your other questions regarding the formula you proposed (with a slight adjustment to the water percentage to include 1% preservative as recommended by the staff):
Your proposed ingredients:

Water approximately 29% (adjusted from 30% to include preservative)
Ethyl Alcohol 20%
Glycerin 20%
Willow Bark Extract (Natural Salicylic Acid) 10%
Lactic Acid (AHA) 88% 10%
Glycolic Acid (AHA) 100% Powder 10%
Phenoxyethanol SA (Preservative) 1%

Mixing Instructions:
Most ingredients can dissolve directly in water and alcohol.

Weigh Water (approx. 29%), Ethyl Alcohol (20%), and Glycerin (20%) into a container. Mix well.
Add Glycolic Acid Powder (10%) and stir until completely dissolved.
Add Lactic Acid (10%) and Willow Bark Extract (10%) and stir until well combined.
Finally, add Phenoxyethanol SA (1%) and stir until evenly distributed.

Storage:
You can store it at room temperature. Avoid hot places and direct sunlight. Refrigeration is not necessary.

Preservative:
It is necessary to add a preservative because the formula contains water, which can be a breeding ground for microorganisms. The staff recommends using Phenoxyethanol SA at a rate of 1%.

pH Meter:
It is highly necessary, especially when using acids at a high concentration like 30%. The pH of the formula is crucial for both efficacy and safety. You should use a pH meter to ensure the pH is within an appropriate and safe range for skin application.

To reiterate, the staff still recommends starting with a lower concentration, such as 5% Glycolic Acid only, for safety when making it for personal use at home.

I hope this information is helpful. Please let me know if you have any further questions.