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How to Formulate with Alpha Hydroxy Acids - AHAs (exclusive)

What are AHAs?

Alpha Hydroxy Acids, also known as AHAs, are chemical exfoliants that help shed dead skin cells from the topmost layer of the skin. They can help soften the skin, even complexion, brighten skin, fade fine lines and wrinkles. They have a range of amazing skin benefits because exfoliating is an extremely important part to a good skin care routine. Regularly exfoliating helps reveal a softer, clearer, brighter and more even complexion.

The two most common AHAs are Lactic Acid and Glycolic Acid. Both of these help exfoliate the skin, but glycolic acid is said to be stronger than lactic acid since it has a lower molecular weight. Glycolic acid penetrates the skin deeper than lactic acid. On the other hand, lactic acid is better for dryer skin or more sensitive skin types since it isn't as strong and it is moisturizing.


If you've never used an AHA before it is recommended to start with a low percentage and slowly work your way up. If you have sensitive skin or it's your first time using an AHA, try a product with 5% or lower lactic acid. Us it 1-2 times a week for about a month. If no irritation occurs then you can up the percentage or try a 5% glycolic acid product.

When I first started using AHAs I stuck with Lactic Acid. My skin was far too sensitive to use Glycolic Acid. Over the years my skin has gotten used to AHA's and now I'm able to use Glycolic Acid. I like to use a 7% glycolic acid toner (startdust toner) and on top I layer a 5% lactic acid serum (moonlight serum). I also use my moon juice jelly mask periodically that has both 3% glycolic and 4% lactic acid. So you can make products with either of these AHA's or both.


I almost forgot to mention. When using AHAs make sure you are wearing SPF for up to a week after use. It makes your skin more sensitive to the sun.


How to formulate with AHAs

The hardest part about formulating with AHA's is that they have an extremely low pH. Their pH is around 0.5 - 2, which is way to low for our skin. So we need to use an alkaline solution to raise the pH to around 3.5 - 5, according to MakingCosmetics.com, which is where I purchased my lactic and glycolic acid.


How to raise the pH?

I have a video that goes into full detail about pH, which I highly recommend you watching before making anything with an AHA. You need to be comfortable with pH and have a lot of experience with working with it in order to formulate with AHA's. You could also read the blog instead if you prefer.

I like to raise the pH using a 10% sodium hydroxide diluted solution.


How to make Buffer solution to raise ph

  • 90% distilled water

  • 10% sodium hydroxide

Directions; weigh out the distilled water in a plastic container. Look for a container that is PP#5 as this is a hard plastic that can withstand heat. I use this one. Next weight out the sodium hydroxide in another container. I use a little glass bowl. Go into a well ventilated room or preferably outside and pour the sodium hydroxide into the water, NOT the other way around. Make sure you pour the sodium hydroxide into the water. You also want to make sure you have gloves, a mask, and protective eye wear on when working with sodium hydroxide. After you pour the sodium hydroxide into the water mix it up. You will notice the solution will become foggy, it may sizzle and it will heat up. This is totally normal. Let it sit until the water runs clear and it returns to room temperature. You can then store the 10% sodium hydroxide solution in a thick plastic container. You want to look for HDPE #2 plastic containers. Add a label onto your container so you know what it is and when you made it.


important note; wear protective clothing like long sleeves, goggles, and gloves when working with sodium hydroxide. Also work in a well ventilated room or outside.

You can also raise the ph using triethanolamine, I've personally never used it, but it does seem to be popular. You can purchase it here. I don't know how to use it, since I have never tried it, I just wanted to share this method with you as well.


Where to buy lactic and glycolic acid?

I purchase both my lactic acid and glycolic acid from makingcosmetics.com

& FSS sells glycolic acid

Keep in mind that none of these contain 100% lactic or glycolic acid. These are all dilutions. I use lactic acid and glycolic acid from makingcosmetics.com so those are the ones I will be talking about.

Their Lactic acid is 88% lactic acid & 12% water.

Their Glycolic Acid is 70% glycolic acid & 30% water.

That means if we wanted to make a product with 5% glycolic acid we would need to use more than 5% in our formula.

So how much do we need to use? You can figure that out by using this calculator.

The calculator will have 3 spots you need to type in numbers and one spot you will keep blank.

In the first column "Stock concentrate" this is the concentration of your dilution. So in this case the lactic acid would be a 88% stock concentrate, and the glycolic acid would be a 70% stock concentrate. So if you are working with the glycolic acid you would type in 70 and if you are working with the lactic acid you would type in 88. You will then go to the right and click on the % sign to switch the calculator from mM to percents.

In the next column "Volume from Stock" keep this spot blank

In the next "Final Concentration" this is how strong you want your lactic or glycolic acid. So if you want to make a 5% glycolic acid toner you would put 5.

In the next column "Final solution volume" always put 100. Because our formulas always equal 100%

Now you can click calculate and in the spot we left blank "Volume from Stock" there will appear a number. This number will be the percentage that needs used in our formula. See video for tutorial.


How to make a basic toner with glycolic or lactic acid

In this experiment I am only going to be using glycolic acid, but keep in mind that everything I mention applies to lactic acid as well.

The first thing we need to figure out is how much pH buffer we are going to need in our formula in order to get the pH to a safe pH for our skin. So how are we going to figure that out? We need to do an experiment.

Let's start with a super basic and plain formula.


5% Glycolic Acid Toner Formula (test)

  • 7.2% glycolic acid

  • 5% glycerin

  • 87.8% distilled water

I purposely left out the preservative because this is an experiment batch and will be thrown away. I honestly don't know why I put glycerin in the formula, that was a waste.

All you need to do is mix all of the ingredients together and then take the pH. Take note of the pH. Then add in a few grams of the pH buffer solution and mix. Let sit for about a minute and take the pH again. I made a 50 gram batch for my experiment and I ended up using 8 grams of my pH buffer solution which got the pH to 4.40

Since I needed 8 grams of my pH buffer in a 50 gram batch that means I will probably need around 16% of my pH buffer in my formula. You may be wondering how I got 16%. When you write a formula your formula will always add up to 100%. So that means when you make a 100 gram batch and your recipe calls for 7.2% glycolic acid then you will use 7.2 grams of glycolic acid. If you want to split that recipe in half, a 50 gram batch, then you could literally just half all of the percentages too. So if your formula calls for 7.2 grams of glycolic acid and you are making a 50 gram batch then you need 3.6 grams of glycolic acid.

I did actually decide to use 15% of my pH buffer since I was worried 16% might be too much. So here is what my new formula looks like.


5% Glycolic Acid Toner Formula

  • 7.2% glycolic acid

  • 5% glycerin

  • 72.3% distilled water

  • 15% pH buffer solution

  • 0.5% liquid germall plus

Just combine all the ingredients together making sure you add in the preservative last. Mix until combined. Check the pH and your pH should be between 3.5 - 5. If the pH is higher than 5 then lower the amount of pH buffer in your formula. If the pH is still too low then you will need to raise the percentage of your pH buffer in your formula.

Now every time you make a product with 5%(7.2%) glycolic acid you will know exactly how much of your pH buffer you need in your formula. You might need to do a little bit of adjusting to the percentage if you are using other ingredients in your formula with a really high or low pH, but in my experience it's never happened. The only time I need to make an adjustment to the percentage of pH buffer is if I increase the percentage of the glycolic acid or add in another AHA like lactic acid.


5% Glycolic Acid Face Wash w/ Coco glucoside

I wanted to try making a face wash based off of our above formula using coco glucoside since coco glucoside has a high pH. Normally when I work with coco glucoside I have to lower the pH. So I wanted to see if I could use the same amount of pH buffer in this formula too.

phase A

  • 1.5% xanthan gum soft

  • 5% glycerin

  • 0.5% liquid germall plus

  • 55.8% distilled water

phase B

  • 7.2% glycolic acid

  • 15% pH buffer solution

phase C

  • 10% foaming apple

  • 5% coco glucoside

Directions:

  • combine the xanthan gum soft, glycerin, & liquid germall plus and mix. Add in the distilled water and mix until thickened.

  • in a separate container combine both ingredients in phase B and mix.

  • pour phase B into phase A

  • combine both ingredients in phase C and then pour into phase A/B

  • check pH and the pH should be between 3.5 - 5

& that's it! Hope you guys found this helpful. This should also work with a moisturizer too. Let me know if you would like me to share an AHA moisturizer formula.






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