Outside of sunscreen, vitamin c in the form of ascorbic acid is one of the most important topical treatments for aging skin. It is loaded in antioxidants and if used correctly, it can reverse free radical damage and promote collagen production. I mention sunscreen because vitamin c will not protect your skin from sun damage, but it can mitigate some of the effects.
Vitamin C naturally occurs in the skin and diminishes with age, excessive exposure to ultraviolet light and exposure to smoke and pollution. Those pesky dark spots that people commonly refer to as “age spots” are not age spots at all– they occur from sun damage. While chemical peeling agents like glycolic acid can gradually reduce dark spots, they work best when paired with an antioxidant like vitamin c.
My recipe for DIY vitamin c serum has some lengthy disclaimers, but the final product will only take you a few minutes to put together. It is really important that you read this post in entirety and decide if you are willing to take the time to measure out all of your ingredients and test the pH level every time that you make it. If you are not, I would not recommend making this serum at home– you will only damage your skin. I have included instructions for storing each small batch and how to add a preservative if you want a slightly longer shelf-life.
Whatever you do, you cannot simply crush up a couple of vitamin c tablets and apply them to your face. Seriously– no matter what any one tells you this will not make an effective DIY vitamin c serum. Even if you are able to find L-ascorbic acid tablets without additives like rose hips, the tablets are loaded with other ingredients and fillers that do not belong on your face. Let’s not even talk about the fact that dietary supplements are not regulated by the FDA in the same way that they regulate food and drugs.
The safest and purest way to make vitamin c serum is to purchase pure L-ascorbic acid. I use a powder from Making Cosmetics that I purchase from Amazon. Unfortunately it is not available with free shipping under Prime, but it is still cheaper than buying the powder (with added shipping costs) on Making Cosmetic’s website. Lotion Crafter is another popular provider of cosmetic supplies and they do have an ultra fine L-ascorbic acid powder. I personally have never tried it, but a lot of beauty bloggers recommend it.
There are just a few things to note before I share the serum recipe. First, unlike making a face mask at home, making a serum requires strict measurements. I recommend buying a scale that can detect as little as 0.1 grams. I use this scale for making cosmetics– its cheap and accurate. It is also really important that you purchase pH strips. I have listed the ones that I use in the ingredients section of the serum recipe.
The amount of vitamin c in your serum needs to be between 10 and 20 percent for effectiveness. If you do not measure correctly, you will make a serum that either is not strong enough to produce collagen or too strong to be effective. Yes, vitamin c actually becomes less effective topically when it is more than 20 percent of the solution.
Like other acids applied topically, vitamin c has an optimal effective pH range. If your serum has a pH level above 3.5 it will not absorb into your skin. If the pH is too low, it can burn your skin. Your final serum pH level should range between 2.5-3.5. This is really difficult to do with just L-ascorbic acid powder and distilled water. You must test your solution with pH strips and add baking soda to increase the alkalinity if necessary.
Anytime you make a skin care product at home, you must take certain precautions to store it properly. When you purchase a product from a store it contains preservatives. These preservatives prevent bacteria and mold from growing in your water-based product. You can add preservatives to your own products easily at home. For water based products, I recommend liquid germall plus. It is an anti-microbial and will slightly extend the shelf life of your vitamin c serum.
If you choose not to add a preservative, I would recommend storing your serum in the refrigerator in a dark-colored bottle with a pump. Unlike a dropper bottle, a pump prevents oxygen from entering the bottle every time you open it. Store your DIY vitamin c serum in the fridge for 3-4 days.
This recipe is for a 1 oz solution at 15 percent. I have included grams for those of you who are using a scale and tsp for measuring by hand. Keep in mind, the only truly accurate way to know the percentage is by using a scale.
1. 4.3 grams L-ascorbic acid powder
– Approximately 1 tsp of vitamin c powder = 4.5 grams. This will give you about a 16 percent serum, but it is easier than trying to measure 0.9 tsp of powder.
2. 21.25 grams or 4 1/4 tsp of distilled water
– You can buy distilled water or make your own at home using the recipe in my rose water toner.
3. 2.5 grams or 1/2 tsp of glycerin
5. If needed: baking soda
1. Measure out your distilled water and pour it into a glass bowl. Any glass or plastic bowl at your house (not metal) will work.
2. Add 4.3 grams (or 1 tsp) of L-ascorbic acid powder to the water and mix until all of the crystals dissolve.
3. Once dissolved, add the glycerin and combine thoroughly. Using your pH strips, test the solution. The serum needs to be between 3 and 4 on your test strip. If the color is too red and matches the 1 or 2 on the guide, you need to add baking soda. Mix a solution of equal parts baking soda and water in a separate bowl and add an 1/8 tsp to the serum. Keep adding until a pH strip indicates the level is between 3 and 4.
4. Using a funnel, carefully pour your serum into the glass bottle. Seal and shake. Store this serum in your fridge. Watch for oxidation. If you serum begins to yellow, it is time to throw it away.
* Note: If using a preservative, add before you test the pH level. You only need to add 0.5 percent of liquid germall plus which will be about 0 .14 grams.
For a hydrating DIY serum for anti-aging, check out my easy DIY hyaluronic acid serum.