Questions about Homemade BHA Toner Formulation, Usage, and Ingredient Compatibility
Question
I have some questions about a homemade BHA Toner formula, especially concerning ingredients, usage, and compatibility with other actives like Azelaic Acid.
1. Can the percentage of Propylene Glycol be reduced to a minimum? What is the lowest recommended percentage? I am concerned about the texture being heavy/oily.
2. Regarding the usage of this formula, should it be applied directly to the skin or wiped with a cotton pad? Should it be left on the skin all day or washed off?
3. Can Zinc PCA be added to this formula? If so, will it affect a subsequent cream containing Azelaic Acid (Liquid Azelaic™)? How many minutes should I wait after applying the toner before applying the cream? Or should Zinc PCA not be added to this formula at all, as I am concerned about potential incompatibility?
4. What is the maximum safe percentage for Salicylic Acid in a homemade formula? I currently use lemon juice on my face daily, leaving it on for about 2 hours before washing off, but it always causes stinging. What percentage of Salicylic Acid should I use for daily application, and what percentage for application every other day, so I can adjust the formula correctly?
5. What is the difference between a formula containing Ethanol and one without? I am not sensitive to Ethanol, but I want to understand the difference.
Answer
Hello! I understand you're interested in making your own BHA Toner to address acne and oily skin, and it's great to hear that your homemade face cream and sunscreen have worked well for you. For your questions regarding the BHA Toner formula you provided, the staff has offered the following advice:
Can Propylene Glycol be reduced? What is the minimum percentage? I'm concerned about the texture being heavy/oily.
- Answer: If Propylene Glycol is reduced below the amount specified in the formula, it might cause Salicylic Acid to precipitate. If you dislike the heavy texture, it's recommended to try replacing Propylene Glycol with Butylene Glycol at the same percentage, as Butylene Glycol has a lighter texture.
How should I use the formula? Apply directly or use a cotton pad? Leave on or wash off?
- Answer: Both methods are possible: applying directly to the skin or using a cotton pad to wipe the face. Whether to leave it on or wash it off depends on your skin's tolerance. Adjust usage to suit your skin. If you have severe acne, you might need to leave it on, but observe if your skin gets irritated. If irritation is high, you should wash it off. The longer Salicylic Acid stays on the skin, the more effective it is, but skin tolerance is key.
Can Zinc PCA be added to the formula? If so, will it affect subsequent creams containing Azelaic Acid? How long should I wait before applying cream? Or should Zinc PCA not be added?
- Answer: It is not recommended to add other ingredients like Zinc PCA to the BHA Toner formula. Since the formula is acidic, other added ingredients might degrade. It is better to add nourishing ingredients to the cream that you will apply after using the BHA Toner.
What is the maximum safe percentage for Salicylic Acid? I currently use lemon juice daily and it stings. What percentage for daily use and every other day use?
- Answer: Lemon juice is likely more acidic than Salicylic Acid. For Salicylic Acid in cosmetics, the FDA allows up to 2.00%. For homemade use, slightly more might be possible, but you must consider your skin's ability to tolerate it. Anything that causes stinging, peeling, or irritation indicates that it is not suitable and is too much.
What is the difference in formulas containing Ethanol? I am not sensitive to Ethanol, but I want to know the difference.
- Answer: Alcohol like Ethanol helps dissolve Salicylic Acid well and helps prevent precipitation. However, the downside is that alcohol dries the skin, which can further increase skin irritation, especially since Salicylic Acid is already somewhat irritating. Therefore, using alcohol in the formula is not recommended.
I hope this information is helpful for adjusting your BHA Toner formula. If you have any further questions, feel free to ask!