This recipe makes a light gel which can easily be used with a dropper or dispenser bottle. For a thicker gel, increase the amount of high molecular weight hyaluronic acid, up to 1% of the recipe. (If increasing both types of HA, you can have the total amount of HA be up to 2% of your recipe.)
Tare the scale and add the hyaluronic acid powders. Mix the powders into the glycerin. Hyaluronic acid powders can take a while to incorporate into the water and other aqueous ingredients. By mixing it with glycerine first, it is much easier to combine all of the ingredients quickly. If you don't want to use glycerin (another humectant), you should allow the hyaluronic acid powders to slowly absorb the water overnight and then you can thoroughly mix together the ingredients.
Tare the scale between each addition of your other ingredients. I've used d-panthenol and collagen, but those are optional ingredients. They can be substituted for more water.
To customize your serum, and add a lovely scent, you can also substitute floral water or a hydrosol for part of the distilled water in the recipe.
Because this product has water-based ingredients, you will need to use some sort of preservative to prevent microbial growth. You should use it at an adequate amount for your particular preservative. (Most natural preservatives are used at around 1% of the product, but some, like Leucidal, need to be used at higher percentages to be effective. Leucidal, for example, is normally used at around 3-4% of most recipes.)
If using a different preservative, you'll want to check the pH of the serum to make sure the pH is in the effective range for your particular preservative!
Thoroughly mix together all of your ingredients until you get a smooth serum. If you find that you have small clumps of HA powder in the serum, you'll want to leave it alone and allow the powder to absorb more of the liquid. After several hours of resting, you should be able to easily blend together the ingredients to get a smooth serum. (Using a small electric mixer can also help.)
Pour the serum into bottles for storing and easy use. I often use small 10ml dropper bottles. For larger amounts, I usually use a pump dispenser to avoid the bacterial contamination that can happen when using a dropper. (See the end of the video. I often touch the dropper to my skin.) With very small quantities, you shouldn't have issues when using a preservative, but it's always best to err on the side of caution with homemade cosmetics. ;)
Recipe printed from Oh, The Things We'll Make! Blog. https://thethingswellmake.com/hyaluronic-acid-serum-recipe/