Summarize:

You can find everything that you will need to make a basic vitamin C serum from a health food store or grocery store. To make a basic vitamin C serum, you will need to gather these ingredients and materials:  1/2 teaspoon of vitamin C powder 1 tablespoon of hot (not boiling) distilled water a tablespoon and a 1/2 teaspoon a small glass bowl a plastic whisk a small funnel a brown or cobalt (dark blue) glass container Pour one tablespoon of hot water into your bowl. Then, measure out ½ teaspoon of vitamin C powder and add it to the hot water.Mix the ingredients together until they are well-combined. Place the funnel spout in the bottle and pour the serum into the funnel to avoid spilling any of the serum. Seal the bottle and store it in the refrigerator for up to two weeks.  The cold, dark environment of your refrigerator will help to keep the vitamin C serum fresh and potent. You can make a fresh batch of vitamin C serum every two weeks or as needed.
Collect your ingredients. Add the vitamin C powder to the hot water. Transfer the basic vitamin C serum to your brown or cobalt glass container.